LABORATORIES FOR THE 21ST CENTURY
BEST PRACTICES
Daylight through
clerestories and
small, stacked
I windows Illuminates
<;] the interior office
*'' area of a laboratory
building at the
National Renewable
Energy Laboratory
(NREL) in Colorado;
the towers help to
distribute heated or
DAYLIGHTING IN LABORATORIES
Introduction
Ma'iicode3404T
1200 Pennsylvania Avenue, NW
Washington DC 20460
202-566-0556
EPA
600
2003.2
Science can improve our lives dramatically, and even change the world as we know it. Therefore, it is important to
provide scientists and other researchers with laboratories that foster innovation and enhance performance. One way to
do this is by designing and building laboratories that make good use of natural light, or daylighting. Daylighting not
only saves energy, it also helps to provide an interior work environment that stimulates creativity and discovery. And
discovery is what research laboratories are all about.
Studies conducted in schools and retail centers show that daylighting helps to increase productivity and enhance
Iformance.*1'2) An increase in productivity of even 1 %—as a result of providing natural light and views to the out-
prs—has been known to nearly offset an organization's annual energy costs. In addition, providing access to natural
ht and exterior views in offices and labs is a good way to recruit and retain top scientists, technicians, and other key
iearch personnel. ,
PxEPA
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
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LABS FOR THE 21ST CENTURY
This guide to daylighting is one in a series on best
practices for laboratories. It was produced by Laboratories
for the 21st Century ("Labs 21"), a joint program of the
U.S. Environmental Protection Agency and the U.S.
Department of Energy. Geared toward architects,
engineers, and facility managers, these guides provide
information about technologies and practices to use in
designing, constructing, and operating safe, sustainable,
high-performance laboratories.
Technology Description
Daylighting is the controlled entry of natural light
into a building. The use of daylighting allows occupants to
dim or turn off a building's electric lights to save energy.
Daylighting is provided through windows, clerestories,
roof monitors, skylights, sawtooth roofs, or special light-
pipe systems. To save the most energy, the designer must
integrate daylighting into the building's overall design,
interior spaces, electric lighting system, and mechanical
systems.
Increasing the amount of daylight in a space entails
more than simply adding windows. Rather, designers
must locate and size windows and other elements to
ensure a relatively even amount of brightness in the build-
ing's interior, avoid excess heat and glare, and minimize
the amount of bright sunlight that falls directly on work
areas.
Although information about how to use daylighting
in commercial buildings is widely available, designers of
daylighting systems for laboratories face different issues.
These differences are primarily due to the large interstitial
spaces between floors, lighting requirements in labs, and
the relative complexity of a laboratory's electrical and
mechanical equipment and systems.
Interstitial spaces above the ceilings in laboratories
are often large, so they can accommodate ductwork and
mechanical and electrical equipment. If space is not need-
ed near the windows for these items, the added floor-to-
floor height provides a unique opportunity for effective
daylighting. The higher that daylight can enter a space,
the farther back it can reach.
Lighting and daylighting requirements in labs can
vary widely. In some labs, access to views is desirable, but
daylighting might not be. In other labs, scientists may
require more ambient light because task lighting is a prob-
lem for them. However, sometimes it is difficult to design
for daylighting in the the lab portion of a building. In that
case, the designer might want to specify daylighting for
offices and public areas, instead. In most labs, less energy
is needed for lighting than for ventilation. But in offices
and public areas, lighting typically accounts for 37% of
energy consumption, and daylighting helps to reduce
both the lighting load and the cooling load.
Given the complex mechanical, electrical and plumb-
ing (MEP) systems in labs, integrating daylighting into the
design of a laboratory building is more challenging than
it is for other building types. For example, MEP systems
may represent up to 50% of a lab's construction budget,®
whereas these systems typically represent 20%-25% in an
office building.
Some designers might be put off by daylighting's
seeming complexities. However, armed with information
about where to start and how to use it, they could soon
make daylighting a "standard practice" for new laborato-
ry buildings.
Daylighting within a space comes from three sources:
(1) exterior light reflected into a building from the ground,
pavement, adjacent buildings, and other objects; (2) direct
light from the sun and sky, which is typically blocked from
occupied space because of heat gain, glare, and ultraviolet
(UV) degradation issues; and (3) internal light reflected
off walls, ceilings, and other interior surfaces.^ The most
common daylighting approaches make use of side light-
ing, top lighting, and atria; other techniques can be used,
as well.
Side lighting. In side lighting, light enters a space
from windows below ceiling height, for views and day-
light. It is a very common daylighting technique.
Horizontal strip windows are often used because they
provide more uniform daylight than individual windows.
Also, windows located higher in a space allow daylight
to penetrate the interior of the space to a greater depth.
If possible, separate windows should be used for views
and for daylighting, because the optimal properties of the
glazings are different for each use (see box on page 7).
The building section shown in Figure 1—which
includes a light shelf, a view window, and a clerestory
window—illustrates a rule of thumb for daylighting the
south side of a building: the distance that daylight can
extend into an interior space is equal to 1.5 to 2 times the
distance (d) from the floor to the top of the window,®
Adding a light shelf distributes the illumination better
and reduces glare, because light shelves help the light
bounce off the ceiling. Exterior light shelves provide more
shade and less glare than interior light shelves do, but
both are best for year-round light distribution. Without
a light shelf, the distance to which daylight can extend
into the space is no more than 1.5 times d. If the light shelf
'*has a reflective top surface, the daylit zone can be up to
2.5 times d.
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LABS FOR THE 21ST CENTURY
Daylight
window
Light.
shelf
View -
window
Figure 1. This section drawing illustrates a rule of thumb in designing for daylighting.
Figure 1 shows the ceiling sloping downward and
away from the window. This improves the quality of light
in the space because the sloped ceiling allows light to dif-
fuse uniformly. A flat ceiling would be darker near the
center. In the configuration shown, ideally the view win-
dow has a lower visible transmittance (VT) than the glass
in the window above the light shelf. (See the box on page 7
for definitions of VT and other terms.)
Performance issues usually depend on orientation. In
the northern hemisphere, south-facing windows require
horizontal overhangs, external light shelves, or internal
and external light shelves to control glare and heat gain.
North-facing windows do not require shading, but they
experience greater thermal losses during the heating sea-
son, which can cause comfort problems. These can be min-
imized by using windows on the north side with a lower
U-value or well insulated windows with low-emissivity
(low-E) coatings. East- and west-facing windows are not
recommended for daylighting because it is difficult to con-
trol glare and heat gain, especially on the west side. If
Curved High Ceiling
Daylight
through
large
double-
height
windows
these windows are used for
daylighting, external vertical
fins for shading or recessed
windows are recommended.
Figures 2 and 3 illustrate
two options for placing
windows high in the space.
Figure 2 shows how the
designers of Building 50 at the
National Institutes of Health
(NIH) complex in Bethesda,
Maryland, took advantage of
large floor-to-floor dimensions
to provide daylighting in a mul-
tistory lab building. Figure 3
(page 4) illustrates how the
Georgia Public Health Laboratory (GPHL) in Decatur,
Georgia, accomplished the same thing. In this example,
staff can see outside through three layers of windows.
Figure 4 (page 4) is a cross section of a planned laboratory
designed for the National Renewable Energy Laboratory
(NREL) in Golden, Colorado. It illustrates how the build-
ing provides daylighting for labs through the use of side
lighting on the north and south.
Top lighting. For top lighting, daylight enters a space
through vertical windows located above the ceiling line.
Windows can be configured other than vertically if
overheating can be avoided, such as by using specially
designed horizontal skylights in deep window wells. Top
lighting can be effective when windows are incompatible
with the function of the perimeter walls, when interior
spaces cannot easily accommodate side lighting, when the
design or lighting criteria make sidelighting inappropri-
ate, or when there are security concerns.
Daylight apertures can face north or south. Baffles
under the roof monitors or deep window wells can be
Equipment
Room
Laboratory Workstations
Aisle
Laboratory
03094301m
Figure 2. This cross section arid photo of laboratories and work stations in Building 50 of the NIH complex shows how daylighting is
achieved through double-height windows.
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LABS FOR THE 21ST CENTURY
Figure 3. The arrows show views from the GPHL laboratory through either two or three sets of windows.
used to diffuse and reflect light in the space. Top lighting Other techniques. Not all buildings or sites are opti-
can also be provided with stepped clerestory windows, mal for daylighting. A square building, or one with a long
sawtooth or roof monitors, or horizontal window wells. axis running north and south, is not optimal. In both cases,
Figure 5 shows top lighting in a classroom building on the there is more east- and west-facing glass than is best for a
Colorado School of Mines campus in Golden, Colorado. daylit building. Even so, some techniques can be helpful.
Light is diffused through a perforated metal ceiling; this For example, designers can orient top lighting to face
prevents glare caused by direct sunlight on computer north and south. Figure 7 is a floor plan of Donald Bren
screens. A cross section of this building is shown in Hall, a classroom and lab building in Santa Barbara,
Figure 6. California. In this building, the windows in the office are
Atria. Adding an atrium is a good way to increase the oriented at an angle from the wall to take advantage of \
amount of space that receives natural light in a building. the primarily southern light. Another technique is to use
An atrium is often a central area one or more stories high vertical or egg-crate-shaped shading devices and selective
(depending on the building's height) with side lighting or surface glazing to reduce heat gain on the east and west
top lighting. Atria are used for daylighting in Pharmacia's sides while retaining some of the view to the outside.
Building Q, a pharmaceutical research laboratory in
Skokie, Illinois.
Lab
Corridor
.Views
outside
Figure 4. Daylighting will enter NREL's planned lab building primarily through clerestory windows on the north and south. Labs will also have
windows for views to the outside.
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LABS FOR THE 21 ST CENTURY
Figure 5. Top lighting used at the Center for Technology and Learning Media (CTLM) building at the Colorado School of Mines,
Design Considerations
Design considerations include the building's footprint
and mass, shading issues, placement of walls and win-
dows, colors of interior spaces, and glazing properties.
Integrating daylighting with electric lighting, the quantity
and quality of light, and codes and standards are also
important considerations.
Building footprint and mass. As much as possible,
specify a long, narrow footprint along an east-west axis; it
is easier to daylight the north and south sides of a building
than the east and west sides. Low sun angles on the east
and west make shading difficult, so glazing ,
should be minimal, especially on the west side.
Window shading. Because a well-designed
daylighting system captures indirect light from
the sun or sky, be sure to shade windows on the
south, east, and west facades from direct sun-
light. Shading options include "self-shading"
windows in deep exterior wall sections, horizon-
tal overhangs, louvers, vertical fins, and light
shelves that can be integrated into the building's
structure. Horizontal shading devices work well
on the south facade. Architecturally, this means
that the north and south facades will look differ-
ent. Vertical baffles, fins, or wing walls are rec-
ommended for east and west facades if windows
are needed there.
Interior colors, ceiling height, and window
height. Specify light-colored interior spaces, tall
ceilings, and high windows to distribute natural
light most effectively. If private offices must be
along exterior walls with windows, specify a
horizontal band of glass that is above eye level
and adjacent to the ceiling on the walls across from the
windows. This provides workers in interior spaces with
natural light and access to views through the private
offices. Also, provide a strip of glazing above shades, so
occupants always have unobstructed windows even when
they close their shades.
Glazing properties. Choose glazing that minimizes
heating and cooling loads and maximizes visual comfort.
See the glazing performance indicators on page 7 for more
information.
Figure 6. Section through classroom block of the CTLM building at the
Colorado School of Mines, showing the top lighting.
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LABS FOR THE 21 ST CENTURY
Integration with electric lighting. Coordinate the
I daylighting design with the electric lighting design so
they work together as one system. This includes defining
, zones for electric lights, selecting proper task and ambi-
?j ent lights, and determining the best control strategy for
'] the lights, including photosensors and occupancy con-
trols. Commissioning the lighting controls system to
make sure it works as designed is an important
consideration. .
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office windows
Figure 7. Windows for the offices of the Donald Bren Hall lab and
classroom building were oriented to take advantage of southern
light in Santa Barbara, California.
Quantity and quality of light. Good daylighting
design is both an art and a science. A daylighting
consultant is a "must" if your architect has never designed
a daylit space. Consultants use computer modeling tools
to size window openings properly/specify glazing proper-
ties, integrate daylighting with electric lights, and specify
the lighting control system. These factors ensure that inte-
rior spaces have the proper quantity as well as quality of
light for a given set of tasks.
Proper light quality is important. Quality issues
include the uniformity of light levels and control of glare
and veiling reflections. Some variation in light levels is
pleasant, but too much causes eyestrain and unnecessary
use of shades and electric lights. A well-daylit space has
relatively even brightness, low contrast ratios (where the
illuminance levels in the space vary by less than a 3:1
ratio), and windows on two sides to provide more uni-
form light. Glare and veiling reflections obscure people's
ability to see details and cause eyestrain. (Glare is extreme
brightness in the field of view; veiling reflections are
caused by vertical specular surfaces, such as computer
monitors, that reflect light into the eye.) A good daylight-
ing system avoids these problems by minimizing or
eliminating direct daylight on visual tasks.
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LABS FOB THE 21ST CENTURY
Codes and Standards
The Illuminating Engineering Society of North
America (IESNA) defines criteria for appropriate lighting,
which depend on the nature of the tasks. IESNA recom-
mends foot-candle levels as well as visual quality guide-
lines to consider in lighting design. The American Society
of Heating, Refrigerating, and Air-Conditioning Engineers
(ASHRAE) standard 90.1-1999 Table 9.3.1.2 lists lighting
power densities for various building types and suggests
1.8 watts (W) per square foot as a guideline for lighting
power density in buildings most like labs. And the
Uniform Building Code specifies the amount of glazing
that can be placed in internal walls, depending on the
hazard rating for the laboratory building and the fire
rating for the specific wall.
Performance Examples
The Labs 21 case studies contain examples of lighting
designs with measured electric power densities of
0.7-1.0 W per gross square foot (GSF) (see page 8 for more
information about the case studies). Monitoring results
show that lighting loads in Pharmacia's Building Q aver-
age 1 W/GSF, and those for Sandia National Laboratories'
Process and Environmental Technology Laboratory
(PETL) are 0.75 W/GSF (though designed for 1 W/GSF).
In both buildings, electronic controls turn off lights in
unoccupied spaces.
Daylighting can be designed as a significant source of
lighting in a space. If automatic lighting controls are used
to integrate daylighting with a building's electric lighting
system, the average measured power density will be sig-
nificantly less than the designed power density, because
electric lights will be used less during part of the day.
Designers can set quantitative performance specifica-
tions, such as the percentage of time that daylighting will
be used rather than electric lighting. If the daylighting and
electric lighting systems are well integrated, in theory the
lighting load will be close to zero between 10:00 a.m. and
2 p.m. on most workdays. Computer models can help
designers verify whether their design meets specifications.
For example, in a new laboratory being designed for one
of the Labs 21 pilot partners at NREL, designers specified
this performance goal: 100% daylighting between
10:00 a.m. and 2 p.m. in office spaces and 50% daylighting
during the same hours in laboratory spaces. A computer
simulation verified that the goal will be met.
Conclusion
Daylighting saves energy, enhances productivity, and
reduces costs associaated with electric lighting. Daylighting
should be considered during the design phase of every
Visibleransmlttanc8(VT)he percentage of visible light that
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new laboratory building. The best time to address it is
during the goal-setting process, when defined, measurable
goals can be specified. A successful daylighting strategy
must be well-integrated with the building's external
image, site, and form as well as its mechanical and electri-
cal systems. Therefore, it is important to set a goal for
daylighting early in an integrated design process.
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8
References
1. Heshong Mahone Group, Daylighting in Schools,
Paacific Gas & Electric Company, August 1999.
2. Romm, J., and W. Browning, Greening the
Building and the Bottom Line: Increasing
Productivity Through Energy-Efficient Design,
Rocky Mountain Institute, 1994.
3. Watch, Daniel, Research Laboratories, John Wiley
and Sons, 2001.
4. Hayter, Sheila J., LANL Sustainable Design Guide,
Los Alamos National Laboratory, <
LA-UR-6914,2002.
5. O'Connor, Jennifer, with Eleanor Lee, Francis
Rubinstein, and Stephen Selcowitz, Tips for
Daylighting with Windows: The Integrated
Approach, Lawrence Berkeley National
Laboratory, LBNL-39945,1997.
Acknowledgements
This best practices guide was written by Nancy
Carlisle of NREL; it is based on information in the
references and in "Labs 21" case studies. The follow-
ing individuals provided very helpful review com-
ments: Sheila Hayter, P.E., and Otto Van Geet, P.E.,
NREL; Geoffrey Bell, P.E., and Paul Mathew, Ph.D.,
Lawrence Berkeley National Laboratory; and Will
Lintner, P.E., U.S. Department of Energy. Paula
Pitchford, editor, and Susan Sczepanski, graphic
designer, NREL, also contributed to this guide.
For More Information
Lawrence Berkeley National Laboratory,
.Daylight in Buildings: A Source Book on Daylighting
Systems and Components, http://gaia.lbl.gov/
iea21. Accessed in April 2003.
Laboratories lor the 21st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.epa.gov/labs21 century/
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous Mure where energy
is clean, abundant, reliable, and affordable
www.eere.energy.gov/
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
Lawrence Berkeley National Laboratory,
Daylighting and Windows, http://windows.
lbl.gov/. See especially Tips for Daylighting with
Windows: The Integrated Approach, LBNL-39945.
Accessed in April 2003.
U.S. Department of Defense et al., Whole
Building Design Guide, http://www.wbdg.org.
Up-to-date information about integrated design
techniques, design tools, and other resources.
Accessed in April 2003.
U.S. Environmental Protection Agency and
U.S. Department of Energy, Laboratories for the
21st Century case studies, http://labs21.lbl.gov/
cs.html. Several case studies feature daylighting.
For an example of the use of atria, see the study on
Pharmacia Building Q; for examples of side lighting,
see the studies on the Georgia Public Health
Laboratory, Building 50 at the National Institutes
of Health, and the PETL at Sandia National
Laboratories, Albuquerque. Accessed in April
2003.
On Laboratories for the 21st Century:
Phil Wirdzek
U.S. Environmental Protection Agency
' 1200 Pennsylvania Ave., N.W.
Washington, DC 20460
202-564-2094
wirdzek.phil@epamail.epa.gov
Will Lintner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120
william.lintner@ee.doe.gov
On Daylighting:
Nancy Carlisle, A.I.A.
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384-7509
nancy_carlisle@n rel.gov
DOE/GO-102003-1766
October 2003
Printed with a renewable-source ink on paper containing at least
50% wastepaper, including 20% posteonsumer waste
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m
sir
-*
LABORATORIES FOR THE 21sr CENTURY
BEST PRACTICES £
* i*
* The Bunting
I Blaustein Cancer
Research Building
in Baltimore,
Maryland, is one
of several
buildings at
Johns Hopkins
that use enthalpy
wheels lor energy
recovery.
ENERGY RECOVERY FOR VENTILATION AIR
LABORATORIES
Introduction
Energy recovery can substantially reduce the mechanical heating and cooling requirements associated with condi-
tioning ventilation air in most laboratories. Laboratories typically require 100% outside air at high ventilation rates—
between 6 and 15 air changes per hour—primarily for safety reasons. The heating and cooling energy needed to
condition this air, as well as the fan energy needed to move it, is 5 to 10 times greater than the amount of energy used in
most offices for those purposes. Heating and cooling systems can be downsized when energy recovery is used, because
energy recovery systems reduce peak heating and cooling requirements.
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
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LABS FOR THE 21ST CENTURY
Front Cross Section
with Upstream Exhaust
Exhaust
Fan
Exhaust
Air
Wheel
Side Cross Section
with Purge Section
Figure 1. Cross sections (front and side) of enthalpy wheel system with purge section
There are many opportunities for energy recovery in
laboratories, and a few of them are covered here. Energy
recovery can occur between any two media or processes
that differ in energy content. The main focus of this guide
is on air-to-air energy recovery—using enthalpy wheels
(Figure 1), heat pipes, or run-around loops in new con-
struction. Most commonly, energy is recovered from
exhaust air and used to precondition supply air. Before
deciding on an energy-recovery technology, laboratory
managers are encouraged to perform a life-cycle cost
analysis to determine the feasibility of the application in
their laboratories. As a rule, the shortest payback periods
occur when the heating and cooling load reduction pro-
vided by an energy recovery system allows the laboratory
to use smaller hot water and chilled water.systems.
This guide to energy recovery is one in a series on
best practices for laboratories. It was produced by
Laboratories for the 21st Century ("Labs 21"), a joint pro-
gram of the U.S. Environmental Protection Agency and
the U.S. Department of Energy. Geared toward architects,
engineers, and facility managers, these guides provide
information about technologies and practices to use in
designing, constructing, and operating safe, sustainable,
high-performance laboratories.
Technology Description
Air-to-air energy recovery devices exchange energy
from one stream of air to another. The air contains sensible
(heat) and latent (water vapor) energy. Both types of
energy can be recovered; however, not all recovery devices
exchange both types of energy. The effectiveness of an
energy recovery device reflects the efficiency of the device
in recovering available energy. Most devices have a rating
for sensible effectiveness; some also have a rating for
latent effectiveness and total effectiveness.
Energy recovery devices increase the pressure drop
across the supply and exhaust fans. Enthalpy wheels
generally have a lower pressure drop than heat pipes and
run-around loops, although the pressure drop depends on .
the design. An additional pressure drop of no more than
1 inch water gauge (1 in. w.g.) in the supply and exhaust
air streams is a reasonable design goal, and it will mini-
mize the increase in fan energy. For example, an increase
in pressure drop of 1 in. w.g. on a 76% efficient fan and
a 95% efficient motor assembly results in an increase in
fan energy of 0.16 watt per cubic foot of air per minute
(W/cfm). The total increase for supply and exhaust fans
together is 0.32 W/cfm.
For laboratory applications, the design face velocity
is typically 500 fpm or less. Lower face velocities result
in lower pressure drops, higher effectiveness, and lower
operating costs. The trade-off is larger air handling equip-
ment and higher first costs. An energy recovery device
will operate more efficiently with a variable-air-volume
(VAV) system than with a constant-volume system,
because VAV systems typically operate at face velocities
lower than those of design conditions.
Enthalpy wheels. Enthalpy wheels, or rotary heat
exchangers, transfer sensible or latent energy (or both)
between the exhaust air and the incoming outside air
(Figure 1). The supply and exhaust streams must be locat-
ed next to each other. Both sensible-only wheels and total
energy wheels, sometimes referred to as desiccant wheels,
are available. A 50,000 cfm total energy wheel can have a
sensible and latent effectiveness as high as 75%, which
results in a total effectiveness of 75%. Control of the wheel
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LABSFOR THE 21ST CENTURY
at part loads is accomplished by varying the speed of the
wheel, or using a bypass duct, or both.
The type of desiccant used in a total energy wheel
must be designed to transfer only moisture and not air-
borne contaminants. To further reduce potential contami-
nation of the supply air stream, the wheel is flushed with
supply air that is deflected by a damper in the purging
section of the rotor. The damper redirects supply air leav-
ing the wheel to the inlet side of the wheel exhaust. The
purge section utilizes the pressure difference between the
supply air and exhaust air streams (see Figure 1). Purge
volumes for laboratory applications are typically between
5% and 10%, so additional fan energy is required to move
this air.
The Whitehead Biomedical Research Building at
Emory University in Atlanta, Georgia, uses enthalpy
wheels for energy recovery between the supply and
exhaust air streams. The installation cost for the wheels
was reported at $425,000, and anticipated energy savings
are $125,000 per year. The simple payback is less than four
years.
Heat pipes. Heat pipes transfer only sensible energy.
If air is cooled to below its dew point, however, condensa-
tion occurs on the heat pipe and results in some latent heat
transfer. In heat pipe applications, the supply and exhaust
air streams are next to one another, although some modi-
fied or "split" heat pipes allow the air streams to be
separated.
The sensible effectiveness of heat pipes is between
45% and 65%. Cross-contamination is not an issue. Heat
pipes have no moving parts, and failure of the entire unit
is rare. A tube may malfunction, but other tubes continue
to transfer energy. Heat pipes can be controlled for part-
load operation with a bypass duct or by tilting the unit.
Heat pipes can be used as indirect evaporative
coolers, in which water is sprayed on the exhaust side of
the pipe to precool the supply air (Figure 2). This applica-
tion has been successful at the Fox Chase Cancer Center
in Philadelphia, Pennsylvania, and in the Process and
Environmental Technology Laboratory at Sandia National
Laboratories in Albuquerque, New Mexico.
Run-around loops. Run-around loops circulate a
fluid between two air streams. This technology may seem
familiar to most designers because it usually just involves
additional coils and pumps. The air streams do not need
to be next to one another, and there are no cross-contami-
nation issues. Run-around loops have a sensible effective-
ness between 55% and 65%. In the U.S. Department of
Agriculture's new laboratory in Ames, Iowa, the preheat
coil and run-around loop coil are combined, so the added
pressure drop in the supply system is lower than that of a
system with separate energy recovery and preheat coils.
Run-around loops are well-suited for transferring
energy between process loads and ventilation air.
Fred Hutchinson Cancer Research Center in Seattle,
Washington, uses a run-around loop to take heat rejected
from the process cooling water system to preheat outside
air, thus providing free cooling of the process cooling
water.
Run-around loops and heat pipes can also be used
to reduce reheat energy by transferring heat from the
outdoor air to a reheat device located next to the
Conditioned
Exhaust
Air
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-------
LABS FOR THE 21ST CENTURY
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Energy recovery from dehumidification cooling coil loop ("wrap-around loop")
Figure 3. Run-around energy recovery loop with dehumidilication
dehumidification cooling coil in warm, Humid climates.
The energy recovery device precools the outside air before
the air enters the main dehumidification cooling coil, and
the dehumidification reheat device reheats the air leaving
the main cooling coil. This preceding and reheating can
be accomplished with a device that wraps around the
cooling coil, often called a "wrap-around loop." It can also
be accomplished with two energy recovery stages between
the supply and exhaust air streams on either side of the
cooling coil. A wrap-around loop can be added to a run-
around energy recovery loop by adding a coil on the
leaving side of the cooling coil (Figure 3). The Viral
Immunology Center at Georgia State in Atlanta, Georgia,
uses a packaged rooftop ventilation dehumidification
unit with two heat pipes. In the summer, one heat pipe
precools the outside air by transferring heat to the exhaust
air, the mechanical system DX coil subcools the air, and the
other heat pipe reheats the air with heat recovered from
the exhaust air. In the winter, both heat pipes are used to
heat the air.
Design Considerations
The following are some considerations that can help
you determine whether air-to-air energy recovery is
feasible for your project.
Schematic Design
• Identify energy recovery opportunities. Manifold
exhaust systems are ideally suited to energy recovery
because all the potentially available energy can be
captured by one energy recovery system.
• Consider the location of the supply and exhaust. If they
can be located next to one other, enthalpy wheels and
heat pipes can be used. Otherwise, modified heat pipes
and run-around loops are best suited for separate
supply and exhaust.
• Consider a wrap-around loop, if enthalpy wheels are
not an option in warm, humid climates where dehu-
midification is necessary.
• Assess the risk associated with cross-contamination
of the air streams. Purge sections on enthalpy wheels
reduce cross-contamination to below 0.1 %, according to
ASHRAE. There are no cross-contamination issues with
heat pipes and run-around loops.
• Address the potential for fouling and corrosion of the
devices. Routine maintenance and controls may be suf-
ficient, although the most suitable equipment depends
on the chemicals being released into the air stream.
Select air filters with a low pressure drop.
• Determine the space requirement for additional equip-
ment needed and its impact on design and costs.
• Estimate operation and maintenance costs for the
device, as well as replacement costs.
• Calculate the impact of energy recovery on energy
costs.
• Include the cost benefit of being able to downsize the
healing and cooling system§.
-------
LABS FOR THE 21ST CENTURY
Design Development and Construction
Documents
• Identify appropriate control strategies for part-load
operation and for preventing condensation and poten-
tial freezing. Using bypass ducts reduces the increase in
fan energy.
• Clearly define the commissioning of the energy
recovery device.
Codes and Standards
As with all building components, various codes and
standards apply to energy recovery. There are standards
for testing the performance of the equipment and stan-
dards that specify when energy recovery must or must
not be applied. American Industrial Hygiene Association
codes and standards affecting laboratories can be found
on the Web (see www2.umdnj.edu/eohssweb/aiha/
technicaI/codes.htm#Energy, accessed in 2003). Here is
a brief overview of codes and standards pertaining to
energy recovery:
• Air-Conditioning and Refrigeration Institute (ARI)
Standard 1060-2000 for Air-to-Air Energy Recovery
Ventilation Equipment rates the sensible, latent, and
total effectiveness of equipment, excluding run-around
loops. The ratings are performed by an independent
laboratory per ASHRAE 84 (see below), except as
amended by ARI 1060. The ARI-certified product direc-
tory (2001) is a useful resource for identifying various
manufacturers and their products and for comparing
effectiveness ratings.
• American National Standards Institute (ANSI)/
ASHRAE Standard 84-1991, Method of Testing Air-to-
Air Heat Exchangers, specifies the data, equipment,
and reporting procedures for testing the sensible,
latent, and total effectiveness of air-to-air heat ex-
changers. There are similar Canadian and European
standards.
• In the most recently adopted version of the
International Mechanical Code (2003), section 514 has
been added to cover the installation of energy recovery
ventilation. This section prohibits the use of all types of
energy recovery ventilation, including heat pipes and
run-around loops, with hazardous exhaust systems, as
defined in section SlO.This is a significant change to the
2000 version of the code.
• National Fire Protection Association (NFPA) 45 (2001)
states that, if there is a chance of cross-contamination
between air streams, air-to-air energy recovery can be
used only on general exhaust. The code has not been
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LABS FOR THE 21ST CENTURY
adopted by all states, although it raises liability con-
cerns for design teams. At the National Institutes of
Health (NIH) Louis Stokes Laboratory and the Nidus
Center in St. Louis, the general exhaust system is
separate from the fume hood exhaust, and there is an
enthalpy wheel on the general exhaust. NIH had to use
stainless steel ductwork for the fume hood exhaust,
because the exhaust was no longer being diluted
enough to allow for galvanized ducts.
• The ASHRAE 90.1-2001 energy efficiency standard for
nonresidential buildings requires energy recovery on
fans of 15,000 cfm or greater in buildings with fume
hoods. Laboratories with VAV fume-hood exhaust or
direct make-up air for the hoods are exempt. The
standard states that the recovery method must have a
minimum total effectiveness of 0.5. This is not always
achievable, although this caveat is often ignored if a
device proves to be cost-effective. Note that the calcu-
lation of fan power limitations in the standard includes
an adjustment for energy recovery.
Performance Examples
Air-to-air energy recovery reduces energy use and
can significantly reduce heating and cooling system sizes.
A large installation of enthalpy wheels done in 1991 at the
Johns Hopkins Ross Research Building has resulted in
millions of dollars in energy savings. All exhaust, includ-
ing fume-hood and biological safety cabinet exhaust, is
passed through the'enthalpy wheels. The equipment paid
for itself in first-cost savings because the hot water and
chilled water systems could be downsized (see Engineered
Systems, September 1995). The enthalpy wheels have per-
formed so well that Johns Hopkins is installing enthalpy
wheels in its new lab buildings, including the Cancer
Research Building shown on the cover of this guide and
the Broadway Research Building, scheduled to be com-
pleted in early 2004.
In 2002, an energy analysis of enthalpy wheels,
heat pipes, and run-around loops was performed for
Laboratories for the 21st Century. It analyzed a typical
100,000-square-foot (sf) laboratory in four locations:
Minneapolis, Denver, Seattle, and Atlanta. The simulation
model assumes a constant-air-volume system (unless
otherwise noted in the study). Electricity rates include an
energy charge of $0.03/kilowatt-hour (kWh), an on-peak
demand charge of $7/kW, and an off-peak demand charge
of $4/kW. On-peak hours are 8 a.m. to 10 p.m., Monday
through Friday. For natural gas, a rate of $0.60/therm is
assumed. (All studies need to use actual utility rates.) The
most significant findings include the following:
Air-to-air energy recovery reduces gas usage for space
heating and reheat for dehumidification by more than
35% in all climates (see Table 1).
Savings in peak electricity demand associated with an
enthalpy wheel depend on climate (see Table 2). No
savings are predicted for heat pipes and run-around
loops, because the increase in the fan energy demand
offsets the decrease in the cooling energy demand asso-
ciated with these technologies.
Annual energy cost savings are $0.27 to $1.95/cfm
of fan air flow (see Table 3). Enthalpy wheels, with
sensible and latent heat recovery, appear to be cost-
effective in all climates. The cost savings obtained with
heat pipes and run-around loops are relatively small in
warm, humid climates; however, using these devices as
wrap-around loops for dehumidification may be cost-
effective.
Only in the hot, humid climate of Atlanta did annual
electricity savings occur with the enthalpy wheel; in the
other climates, the increase in annual fan energy offset
the annual electricity savings.
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-------
LABS FOR THE 21ST CENTURY
• The greatest reduction {approximately 20%) in chiller
size occurs with enthalpy wheels in humid climates;
the savings are approximately half this amount with
sensible-only recovery devices. In the dry Denver
climate, the potential reduction is 10% with all three
devices.
• The minimum reduction in boiler size is 15% with any
of the devices. If the building is also being humidified
in the winter, the additional latent energy recovery with
enthalpy wheels results in up to a 50% reduction in
heating and humidification requirements.
At the 120,000-sf Fox Chase Cancer Center in
Philadelphia, heat pipes with bypass sections were
installed in two 30,000-cfm air handling units. The incre-
mental cost for heat pipes with the indirect evaporative
cooling option on the exhaust was $300,000. Anticipated
energy cost savings were $72,510, resulting in a simple
payback of 4 years.
Conslusion
Installing energy recovery systems can substantially
reduce the cost and use of energy in laboratories. Selecting
an appropriate energy recovery technology, properly
designing the system, meeting the applicable codes, and
commissioning the system are all important. When an
energy recovery system is design, installed and operated
correctly it will provide significant energy and environ-
mental benefits.
Key terms
, , - ~ .~ , .
S- 'iffBeliveflBssiJhe ratio of factual energy recoyered.tp «,;.-
j theoretical .energy that could be recovered. : ' •;•; -vl I-H :f * s ->• -; ;i
! .-. "'••• «,.•>:.'- -••/ ;.:•;>•••• ;. < '.?•?• --:!.-.i/i ";4";'-!'->;i -i
} " Latent energy: The energy contained in;moisture: ,; •;•"",:.$%«.?.". .,ij
I and^edifferenciEi:bet^hth'ehumidity.Fat|o:of.Uie/c^w^.airj|;
;< and the outside air.
; Sensible 8nergy:The energy associated with a temperature V
difference, . '. M' V ..,,:-J'VJ ^MSl'^ X?\
* '..;:* . T-"'.-''•• 5 :<.•'!•?'. ,' "*•",-• *~\ *','~!-'•'•$:,:; •b'x •; .•;•;':
{- difference between the dry-bulb temperature ofithejoutsicie air;/;;'^
f and supply a^;andtfjie$iffej*h^
i.temperature of the exh'austair arid the outside air.-.g =•.-,; v ••-'['., !^\
I'' Total effectiveness: Proportidnai to the'raUo;p|uie;|fffe|wjce.,!; -^
I between the enthalpy'of the outside air] M^'thj8|s5p^[yjdr^ahd V.' ]
iv Ihe difference between the enthalpy of trie exfiauslairahditrie'Z '* !
| outsideair.: ••'',. '•• --"• » '~: •>••"•"';.,..-!'-?' ^-';•:, /'<*•
Acknowledgements
We wish to thank the primary author of this guide,
Sue Reilly of Enermodal Engineering, Inc. This guide
would not have been possible without the additional
contributions of Mike Walsh of Vanderweil Engineers,
Inc.; Michael Dausch of Johns Hopkins; and John Fisher of
SEMCO. Nancy Carlisle, Otto Van Geet, Paula Pitchford,
editor, and Susan Sczepanski, graphic designer, all of
NREL, also contributed to this best practices guide.
For More Information
The different types of air-to-air energy recovery
devices are discussed in numerous sources. For example,
the American Society of Heating, Refrigerating, and Air-
Conditioning Engineers (ASHRAE) Handbook of Heating,
Ventilating, and Air-Conditioning Systems and
Equipment covers a wide range of devices, compares their
performance, and identifies appropriate applications.
The ASHRAE Laboratory Design Guide by Mclntosh
et al. includes a chapter on energy recovery and discusses
laboratory-specific concerns. Also, A Design Guide for
Energy-Efficient Research Laboratories is available in
electronic format from Lawrence Berkeley National
Laboratory. This searchable document includes a discus-
sion of different types of energy recovery as well as case
studies.
Also, the U.S. Environmental Protection Agency and
the U.S. Department of Energy have prepared several
Laboratories for the 21& Century case studies (http://
Iabs21.lbl.gov/cs.html). Several case studies feature
energy recovery; for an example of enthalpy wheels, see
the studies on Pharmacia Building Q, the Nidus Center,
and Building 50 at the National Institutes of Health; for
an example of heat pipes, see the study on the PETL at
Sandia National Laboratories, Albuquerque. Several other
good sources of information are listed below.
Air Conditioning and Refrigeration Institute (ARI).
2001. Air-to-Air Energy Recovery Ventilation Equipment
Certified Product Directory. ARI, Arlington, VA
(www.ARI.org).
ARI Standard 1060.2001. Rating Air-to-Air Energy
Recovery Ventilation Equipment. ARI, Arlington, VA.
ANSI/ASHRAE Standard 84-1991 (ARI 1060). 1991.
Method of Testing Air-to-Air Heat Exchangers. American
Society of Heating, Refrigerating and Air-Conditioning
Engineers, Inc., Atlanta, GA (www.ashrae.org).
Cockerham, K. 2000 (July). "A Tale of Two Systems."
Consulting Specifying Engineer.
DiBlasio, R. 1995 (September). "Conditioning a
Research Facility." Engineered Systems.
-------
8
Gibson, Tom, 1999. "Special Ventilation System
Helps Prevent Release of Dangerous Agents at
Georgia State," The News: Air Conditioning,
Heating and Refrigeration.
International Code Council, 2003. International
Mechanical Code. ICC, Falls Church, VA.
Mclntosh, I.; Dorgan, C.B.; and Dorgan, C.E.,
2001. ASHRAE Laboratory Design Guide. American
Society of Heating, Refrigerating and Air-
Conditioning Engineers, Inc., Atlanta, GA.
National Fire Protection Association 45,2001.
Standard on Fire Protection for Laboratories Using
Chemicals. NFPA, Quincy, MA.
National Wildlife Federation, 2002. Emory
University Campus Ecology Yearbook 2001-2002.
NWF, Reston, VA.
Paarporn, S., P.E., 1999. "Run-around Loop
Heat Recovery with Dehumidification System."
ASHRAE Journal, June.
Reilly, S., and Van Geet, O., 2003. Laboratories
for the 21st Century Energy Analysis. U.S.
Environmental Protection Agency and U.S.
Department of Energy Federal Energy
Management Program, Publication No. DOE/
GO-102003-1694. Prepared by the National
Renewable Energy Laboratory, Golden, CO,
http://labs21.lbl.gov/docs/labs21energyanaL
33410.pdf.
On Laboratories for the 21st Century:
PhilWirdzek
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W.
Washington, DC 20460
202-564-2094
wirdzek.phil@epamail.epa.gov
WillLintner,P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120
william.lintner@ee.doe.gov
On Energy Recovery:
Otto Van Geet, P.E.
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384*7369
otto_vangeet@nrel.gov
Sue Reilly, P.E.
Enermodal Engineering, Inc.
1554 Emerson Street
Denver, CO 80218
303-861-2070
eeinc7@qwest.net
Laboratories for the 21st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.epa.gov/labs21century/
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous Mure where energy
is clean, abundant, reliable, and affordable
www.eere.energy.gov/
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
DOE/60-102003-1774
October 2003
Printed with a renewable-source ink on paper containing at least
50% wastepaper, including 20% postconsumer waste
-------
Laboratories for the 21st Century
Best Practices
MODELING EXHAUST DISPERSION FOR SPECIFYING
ACCEPTABLE EXHAUST/INTAKE DESIGNS
Introduction
This guide provides general information on specify-
ing acceptable exhaust and intake designs. It also offers
various quantitative approaches (dispersion modeling)
that can be used to determine expected concentration
(or dilution) levels resulting from exhaust system emis-
sions. The guide, one in a series on best practices for
laboratories, was produced by Laboratories for the
21st Century ("Labs 21"), a joint program of the U.S.
Environmental Protection Agency (EPA) and the U.S.
Department of Energy (DOE). Geared toward architects,
engineers, and facility managers, the guides contain
information about technologies and practices to use in
designing, constructing, and operating safe, sustainable,
high-performance laboratories.
Studies have shown a direct relationship between
indoor air quality and the health and productivity of
building occupants.^'2'3) Historically, the study and pro-
tection of indoor air quality has focused on emission
sources emanating from within the building. For exam-
ple, to ensure that the worker is not exposed to toxic
chemicals, "as manufactured" and "as installed" con-
tainment specifications are required for fume hoods.
But emissions from external sources, which may be re-
ingested into the building through dosed circuiting ,. . _. . . ,
. ,,.,..,, , . . . , Figure! Photographs of wind tunnel simulations showing fumes
between the building s exhaust stacks and air intakes, exjtJng fum6 ho0(J exhaus, stacks |n ,ookjng a| ^ photo*raph) we
are an often overlooked aspect of indoor air quality. should ask: Are the air intakes safer than a worker at the fume hood?
% Only a detailed dispersion modeling analysis will provide the answer.
vvEPA
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
-------
LABS FOR THE 21ST CENTURY
I
I If the exhaust sources and air intakes are not prop-
erly designed, higher concentrations of emitted chemicals
may be present at the air intakes than at the front
j of the fume hood, where the chemical was initially
\ released. Furthermore, if a toxin spills within the fume
| hood, the worker can take corrective action by closing the
sash and leaving the immediate area, reducing
his or her exposure to the released chemical vapors.
Conversely, the presence of the toxic fumes at the air
intake, which can distribute the chemical vapors through-
out the building, typically cannot be easily
mitigated. The only option may be to evacuate the entire
building, which results in an immediate loss of productivi-
ty and a long-term reduction in occupant satisfaction with
the working conditions.
Dispersion modeling calculates the amount of fume
reentry, or the concentration levels expected at building
air intakes and ensures a "good" exhaust and intake
design. This includes mechanically driven air intakes,
naturally ventilated intakes such as operable windows
and entrances, and leakage through porous walls.
Petersen et al.W) gives a technical description of
various aspects of exhaust and intake design. Some
of the challenges of specifying a good stack design
mentioned in that article include the existing building
environment, aesthetics, building design issues, chemical
utilization, source types, and local meteorology and
topography. For example, if a new laboratory building is
being designed that is shorter than the neighboring build-
ings, it will be difficult to design a stack so that the exhaust
does not affect those buildings. Figure 1 illustrates the
effect of a taller downwind or upwind building. The figure
shows how the plume hits the face of the taller building
when it is downwind and how, when it is upwind, the
wake cavity region of the taller building traps the exhaust
from the shorter building. In either case the plume has an
impact on the face of the taller building.
Typically, laboratory stack design must strike a
balance between working within various constraints and
obtaining adequate air quality at surrounding sensitive
locations (such as air intakes, plazas, and operable win-
dows). The lowest possible stack height is often desired
for aesthetics, while exit momentum (exit velocity and
volume flow rate) is limited by capital and energy costs,
noise, and vibration.
Exhaust and Intake Design Issues
Qualitative Information on Acceptable Exhaust
Designs
Several organizations have published standards for or
recommendations on laboratory exhaust stack design, as
summarized in the sidebar.
p £e iifira i iD'eisi fnIG u i I ill l!nSsMrl5^
'.«-...•: !::: . »-•••>•: ••• 1-' -• • - -
£. ZfClJocate intakes aw^framp'i:*' A f:;"l-'.'
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';rf f a/idIpffibi^^ts^liH-rP^i^^^^^HPHHHI^H^:- V
! ^3]t DpnftiMiitealrlntakes'w^ : •: "" ;.
v^;fe^cjps:u'r^BCpr^^ .1:, , ":
jl 4. Avoid locating intakes near .V::' ^fj||j§|iff JJ^^^||(MBM £ • '
|:::;r. vehicle loading zones: Canopies pBEBMaiJIPffl^^SM^ ' :
j--- ; i over loading dpckstlk) neit^.j 3* f
|Ud,! prevent hot vehicle exhaust '>- ~ '•
f ~1,,: Ifrom rising to intakes above the:!
Ns. -I CombinCseveral exhaust - f-?_;;
[J K!- strearns Internally to d|iute1-lf i;
{": i;;/jisouriD3!and to produce an- iN:i;H=
i;.| ^fexrtau^wittigreater^imejijlj|
\ 'f-t '< rjse^Additional air volume rnayi-i
["• J:v' bV added fbrthe.exfiaust'at .f |f *
iVs!' "i"thiB!fah to achieve the sariie1' .i
p;K:L;endj||lNp|et|iatWrni^rece^ : -'= ~[
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?;;:cf;fshall be independOTtofflmer^es^ Vv'. V '
|; i";;= may preclude manrroldin^ - J," •. "•'
proposed changes eKdude rese^h latoratoriesfrom^ •;,;!. •;'
> 6. '• Group separate stacks together
I"; ; [{whereseparateexhaiistrr: ;~" |
?' >;:= systems are mandated) in a; 3 |
I ..i ;;1;t|ghttl^r;tptal(»ady^frtage:;=d
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I f * 4 from the resulting combined~~.*\
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: operate continuously to take i
dH;J=MI ^whteigpofth^cpmbinedj
,- r momehtum. If not all of the j :
[• -•**-;.Hazardous exhaust systems are designed.tb capture and control hazardous*
f '^'emissions generated from^roducUiandling of processes and convey them ••'- - •'\- ''
' ;tothe outdoors. Hazardous emissions indude flammable vapors, gases, . ','
I J- -fumes,:m(sts,ordustsi along with volatile orairbornematerialstJiatpose--" .'.- '-' ;;
|i,/j; \aheatthhazard,suchastoxiccfc6rrbsivematerials.W .-. - -.. \<
-------
LABS FOR THE 21ST CENTURY
same time, however, such as In an n+1 redundant system, the tight ',
placement of stacks may be detrimental to their performance. < •
1 i '
7. Maintain an adequate exit
),! .velocity to avoid stack-tip ...... t,?,
I down wash. The American * 8
'••'
Hygiene AssocfeMpn W'W;-;3
'' •
",;" I >->. standard for laboratory Vi! • j;t^Hfl8i!PPPiPKiiSi!^
• -: ;:: ; from an exhaurt start s^^ ;; !j
....;' Society of Heating, Refrigerating.indAir-Condmoning Engineers; ]S;:.i
> ,;, •;.. (ASHRAE)(^recommends a minimum exitvelocityof 21000 to ; rK...:: '•'}
- - . , .,
,8. Apply emission controls where v^l&;Thisn»y|ndud(( installing i ! ,
:• .restiMveflowWifce^com^
;_V ]?: systems for diemical specific releases, lov^Ndx|6^s;rf[:";[;f.;
"'' j'/nitn^n) unite for bpi^
"it"; filters w catalytic converters foremieitie^g
..,y;9. j Avoid rain caps or otheri r: :.|jj|jw||j|jj|||m
' devices that limit plume rise, j;
, .- . ;: s -on exhaust stacks. Although ; ;
',- widely used, conical'rairi "" 1;
' ; • • •' rcaps are not necessarily ::J ': •;
, ' - ' . effective at preventing rain: • ;
., from infiltrating the exhaust ~.."'.
"
typically fall straight down. Alternate design options are presented in;- 'f
^ ..„ . , „
" -.10. Consider the effect oir" :: |
, , ., architectural screens. An .-.
studyW found that screens,/
•'..-? cansigniflcanttyincrease '
. concentrations on the roofr
, and, in effect, reduce the
effective stack height A solid screen can decrease the effective . "; j
* stack height by as much as 80%. Alternatively, the effect of the '
.;.'•- screen can be minimized by installing a highly porous screen ;
' .~.'i'*SSMSt**»..
,«;,,.,.«*W!^5*i
1!
, ; -11. Avoidadirect linei of sight ;,;.:
'" . - - betweerfexhaust stacks ;• i: v"
; s .: -, and air intakes. An ASHRAE c! !
k-f'- . . research projectO°) '.* t:. : ":J
, , . demonstrated that there - "]
', , is a distinct reduction in i :,:
- ,;,'• •] air intake concentrations';;;, '^j^
, from rooftop exhaust stacks when air intake louvers are "hidden" • i\
-. *.' . " . , ^ i t-:' . ,. j: 5. ; - -;'3if:> =V";;»l;:s"'>'.,--s,--u^ ^^*(ri- ..\i\' '.'*. 'j
• , on sidewalls rather ftaii placed on the rool. Depending on^Wespecificg;i J
.'•',' i configuration, concentrations along the sidewall may be half toa full ::' 'j -;|
- ,' orterofmagnitudeiesswanU10sepiBsentbnme!robf/;,^f J
• •'. i\ rvVW • - -v rj ;- n ' • :'•:- "*, :: ".i -! ^..,;; f fcVtf ••, *?$
' '•'-; -•• •••- ••"• '-''
m-
Exhaust Design Criteria
Laboratory design often considers fume hood stack
emissions, but other pollutant sources may also be associ-
ated with the building. These could include emissions
from emergency generators, kitchens, vivariums, loading
docks, traffic, cooling towers, and boilers. Each source
needs its own air quality design criteria. An air quality
"acceptability question" can be written:
where Cmax is the maximum concentration expected at a
sensitive location (air intakes, operable windows, pedes-
trian areas), Chealthis the health limit concentration, and
Odorls t^6 0<*or threshold concentration of any emitted
chemical. When a source has the potential to emit a large
number of pollutants, a variety of mass emission rates,
health limits, and odor thresholds need to be examined. It
then becomes operationally simpler to recast the accept-
ability question by normalizing (dividing) Equation 1 by
the mass emission rate, m:
(2)
health/odor'
The left side of the equation, (C/m)max, is dependent
only on external factors such as stack design, receptor
location, and atmospheric conditions. The right side of the
equation is related to the emissions and is defined as the
ratio of the health limit, or odor threshold, to the emission
rate. Therefore, a highly toxic chemical with a low emis-
sion rate may be of less concern than a less toxic chemical
emitted at a very high emission rate. Three types of infor-
mation are needed to develop normalized health limits
and odor thresholds:
1. A list of the toxic or odorous substances that may be
emitted
2. The health limits and odor thresholds for each emitted
substance
3. The maximum potential emission rate for each substance.
Recommended health limits, Cj,eaMv are based on the
ANSI/AIHA standard Z9.5-2003,<8> which specifies that
air intake concentrations should be no greater than 20% of
the acceptable indoor concentrations for routine emissions
and 100% of acceptable indoor concentrations for acciden-
tal releases. Acceptable indoor concentrations are fre-
quently taken to be the short-term exposure limits (STEL),
which can be obtained from the American Conference of
Governmental Industrial Hygienists (ACGIH), the
Occupational Safety and Health Administration (OSHA),
and the National Institute of Occupational Safety and
Health (NIOSH), as listed in ACGIH.dM2) ACGIH can
also furnish odor thresholds, (
,;
-------
LABS FOR THE 21ST CENTURY
B:j I^MM^-A^yM^^^^QK^M^^
»i
II
IV.
laboratoiyfume".hood |
]S: : '^y t."~~- II: ':< j.i ••••* ; " ;F~ir'
400-hp diesel track , j y =• - ! ;;: ;- i ^ :'-f .>
:.""; 'v ~" "L i= •? ••- * --'' •> \, :'•'::?: ::'S!*j!:iN!"!;>»r"Si«^a^!g:;:!ii;:!':r!,-rFv''";? £"s»".;:^;rs!'T;; ;:'•: 2- v^->,n'»i;rr.~ ~r
!•: *; This criterion is more restrictive than the 0.05 ppm criterion stated in Z9.5-2B03(^ for the m^imum concentration present at th^ fume hood,
'f.t. ^dmSiz^icpnciBiitraliM desigh criteria thai are basedi on dilirtjpn standards are dependent oh the volume flow rate through the exhaust stock.1' •'" ;• , -
For laboratories, the emission rates are typically based Wind-tunnel modeling is often the preferred method
on small-scale accidental releases, either from spilling a for predicting maximum concentrations for stack designs
liquid or emptying a lecture bottle of compressed gas. For and locations of interest, and is recommended because it
other sources, such as emergency generators, boilers, and gives the most accurate estimates of concentration levels
vehicles, chemical emissions rates are often available from in complex building environments.^) A wind-tunnel
the manufacturer. Table 1 outlines typical design criteria modeling study is like a full-scale field study, except it
for various sources. is conducted before a project is built. Typically, a scale
model of the building under evaluation, along with the
surrounding buildings and terrain within a 1000-ft radius.
Concentration predictions (C/m) at sensitive locations is placed in an atmospheric boundary layer wind tunnel.
can be accomplished with varying degrees of accuracy A tracer gas is released from the exhaust sources of inter-
using three different types of studies: (1) a full-scale/ie/rf est, and concentration levels of this gas are then measured
program; (2) a reduced scale wind-tunnel study; or (3) a at receptor locations of interest and converted to full-scale
mathematical modeling study. concentration values. Next, these values are compared
A full-scale field program, although it may yield the aSainst *« appropriate design criteria to evaluate the
most accurate predictions of exhaust behavior, may be acceptability of the exhaust design. ASHRAE<6> and the
expensive and time consuming. If the nature of the study EPA(14) provide more information on scale-model simula-
is to estimate maximum concentrations for several stacks tion and testing methods.
at several locations, many years of data collection may be Wind-tunnel studies are highly technical, so care
required before the maximum concentrations associated should be taken when selecting a dispersion modeling
with the worst-case meteorological conditions are mea- consultant. Factors such as past experience and staff
sured. In addition, it is not possible to obtain data for technical qualifications are extremely important.
future building configurations.
-------
LABS FOR THE 21ST CENTURY
Mathematical models can be divided into three cate-
gories: geometric analytical, and computational fluid
dynamic (CFD) models. The geometric method® defines
an appropriate stack height based on the string distance
between the exhaust stack and a nearby receptor location.
This method is entirely inadequate for exhaust streams
that contain toxic or odorous material because it does not
yield estimated concentration values at air intakes or other
sensitive locations. Hence, no information is provided for
stack designs to avoid concentrations in excess of health
or odor limits.
Analytical models assume a simplified building con-
figuration and yield concentration estimates based on
assumed concentration distributions (i.e., Gaussian).
These models do not consider site-specific geometries
that may substantially alter plume behavior; thus, concen-
tration predictions are not as reliable. When properly
applied, the analytical equations provided in the ASHRAE
handbook on HVAC applications^6) will tend to give con-
servative results for an isolated building or one that is the
same height or taller than the surrounding buildings and
has air intakes on the roof. As such, the analytical model
can be useful for screening out sources that are unlikely to
be problematic, thus reducing the scope of more sophisti-
cated modeling. Neither the geometric nor the analytical
models are appropriate for complex building shapes or in
locations where taller buildings are nearby.
The most common type of computational fluid
dynamics resolves fluid transport problems by solving a
subset of traditional Navier-Stokes equations at finite grid
locations. CFD models are used successfully to model
internal flow paths within areas such as vivariums and
atriums, as well as in external aerodynamics for the aero-
space industry. The aerospace CFD turbulence models,
however, are ill suited for modeling the atmospheric tur-
bulence in complex full-scale building environments
because of the differing geometric scales. This is exempli-
fied in the conclusions of Castro's recent evaluation of
applying CFD to the built environment:
"Despite considerable effort over the last two decades,
there is no agreed modeling approach which will auto-
matically yield accurate results for the surface pressure
field on and/or the flow field around buildings in the
wind.. .Only large eddy simulation (LES) techniques
genuinely have the potential to yield adequate mean and
fluctuating data, but these have yet to be fully developed
for complex bluff body flows."(15>
Based on the current state of the art, CFD models
should be used with extreme caution when modeling
exhaust plumes resulting from laboratory pollutant
sources. At this time, current research indicates that CFD
models can both over- and underpredict concentration
levels by orders of magnitude, leading to potentially
unsafe designs. If a CFD study is conducted for such an
application, supporting full-scale or wind-tunnel valida-
tion studies should be carried out
Effective Stack Height and Induced-Air Fans
Induced-air fan manufacturers often quote an "effec-
tive stack height" for their exhaust fan systems. Many
designers incorrectly interpret this value to be a physical
stack height and compare it to the height requirement
defined from a dispersion modeling study. The manufac-
turer's specified effective stack height is actually a predic-
tion of the exhaust plume centerline's final height, based
on a mathematical plume rise equation. (fi) This final height
typically occurs far downwind of the exhaust stack (on
the order of 100 to 200 ft). A more general mathematical
equation is available that predicts the height of the plume
centerline as a function of downwind distance.^4) A better
method of comparing two different exhaust systems is to
specify the effective increase in the plume height versus
downwind distance. The increase may not be as great as
one might expect, as the following analysis points out.
Figure 2 shows the predicted plume centerline height
versus downwind distance for an induced-air exhaust
stack and a conventional exhaust fan system at a 20-mph
stack height wind speed. The curves indicate that the dif-
ference in the plume height between the two exhaust sys-
tems is only 1 to 2 ft at 20 ft downwind with a maximum
difference of 6 ft after both plumes have reached their final
rise. Therefore, using an induced-air fan may reduce the
35
: 30
10
Downwind Distance (m)
20 30 40 50
60
70
I-25
20
15
10
5
• Conventional
• Induced
• Difference
9.2
6.1 g
3.1
a
cu
I
50 100 150
Downwind Distance (ft)
200
250
0.0
Exhaust Parameters
Stack height (ft, m)
Stack diameter (in., m)
Discharge flow rate (cfm, m/s)
Exit velocity (fpm, m/s)
Wind speed (mph, m/s)
Fan power (bhp, bkW)
Conventional
10.2
30.3
15,000
3,000
20
14.5
3.10
0.77
7.08
15.24
8.94
10.8
Induced-Air
10.2
45.0
32,466
2,940
20
17.86
3.10
1.14
15.32
14.94
8.94
13.3
Figure 2. Plume centerline height for conventional and induced-air
exhaust systems
-------
LABS FOR THE 21ST CENTURY
necessary stack height by only a few feet, depending on
the location of the nearby air intake locations. This analy-.
sis shows why the effective stack height specification is
misleading.
Plume Rise and Exit Velocity
Adequate plume rise is important to ensure that the
exhaust escapes the high turbulence and rerirculation
zones induced by a building's roof. Plume rise increases
with increased exit momentum and decreases with
increased wind speed.(14) Reducing the diameter to
increase exit velocity will increase the exit momentum and
thus the plume rise. There are limitations on how much
the exit velocity can be increased before noise, vibration,
and energy problems develop. Therefore, it is often prefer-
able to increase the plume rise by augmenting the volume
flow rate, possibly by bringing in additional air via a by-
pass damper at the base of the stack. Plume rise is adverse-
ly affected by atmospheric turbulence because the vertical
momentum of the exhaust jet is more quickly diminished.
In areas of high turbulence, then, the only method for
obtaining an adequate plume centerline may be to increase
the physical height of the stack.
If the ratio of exit velocity to approach wind speed is
too low, the plume can be pulled downward into the wake
of the stack structure, creating negative plume rise, a con-
dition called stack-tip downwash. This downwash defeats
some of the effect of a taller stack and can lead to high
concentrations. The photo that accompanies Item 7 in the
"General Design Guidelines or Standards" sidebar on
page 3 of this guide shows an example of this phenome-
non. A rule of thumb for avoiding stack-tip downwash is
to make the exit velocity at least 1.5 times the wind speed
at the top of the stack.W This stack top wind speed is
commonly taken to be the 1% wind speed, which can be
obtained from ASHRAE for various worldwide metropoli-
tan areas.&$ Note that the ASHRAE-provided wind speed
must be adjusted from the anemometer location to the
stack top.d7>
Variable volume exhaust systems should be designed
to maintain adequate exit velocity during turndown peri-
ods. The exit velocity should be sufficient to avoid stack-
tip downwash at all times. A high exit velocity can be
maintained either by having adjustable makeup air at the
exhaust stack via a by-pass damper or by employing sever-
al stacks that can be brought on/off line in stages as flow
requirements change. Products are also available that can
change the geometry of the stack exit in an attempt to
maintain a high exit velocity with variable volume flow
rates. Many of these devices do not properly condition
the flow as it exits the stack, which reduces the vertical
momentum and ultimately the plume rise out of the stack.
As an alternative, smart control systems can be used to set
minimum exit velocity requirements based on the current
wind conditions measured at a nearby anemometer.
Energy Issues
Several factors affect exhaust system energy con-
sumption, including (1) the design and operation of the
laboratory, specifically the relative location of exhaust
sources and air intakes, the presence of nearby building
elements such as screen walls and penthouses, the exhaust
volume flow rates and exit velocities, and the chemical
utilization within the fume hoods; (2) the environment
surrounding the laboratory, involving the presence of
nearby structures, air intakes, and other critical receptor
locations; and (3) the local meteorology, specifically the
distribution of local wind speeds and wind directions.
Chemical utilization is the basic criterion used to
judge whether a specific exhaust/intake design is accept-
able. An overly conservative judgment about the potential
toxicity of an exhaust stream may result in a high-energy-
use exhaust system as volume flow or exit velocity is
increased unnecessarily. A more accurate assessment of
the intended chemical use, with some consideration of the
future program, will result in an exhaust system that
yields acceptable air quality while consuming a minimum
amount of energy.
Local wind speeds may be used to set exit velocity
targets, as discussed previously. Exhaust momentum,
however, is the true parameter governing exhaust plume
rise and dispersion. In cases of high-volume flow-rate
exhausts (i.e., 30,000 cfm or greater), studies have shown
that exit velocities as low as 1000 fpm can produce accept-
able plume rise and dispersion. Specific designs should be
evaluated on a case-by-case basis, regardless of exhaust
design parameters, to ensure that adequate air quality is
maintained at all sensitive locations.
Figure 3 was developed using the laboratory fume
hood criteria and the analytical models for dispersion
described previously. The figure shows that as volume
flow rate increases, shorter exhaust stacks can be used to
meet the design criteria. The shorter stacks, however, are
obtained at the cost of increased exhaust fan power. The
figure also demonstrates the advantage of manifolding
exhaust systems. For example, a single stack operating
at 5000 cfm should be approximately 22 ft tall to achieve
the design criterion at a receptor 160 ft downwind.
Conversely, five stacks operating at 1000 cfm would
need to be nearly 38 ft tall to provide the same air quality
at the same receptor location.
Figure 4 shows how fan power may increase with
exhaust flow rate for various system designs. The figure
illustrates the relationships between the design volume
flow rate, Q, and the fan power requirements for two
-------
LABS FOR THE 21ST CENTURY
Design Criterion 400 ug/m3 per g/s
Ve = 3,000 rpm (15.2 m/s)
Distance from Stack (m)
6.1 18,3 30.5 42.7 54.9
• 1,000 eta (0.47 mVs)
• 5.000 cfm (2.36 mi/s)
• 10,000 dm (4.72 ir«s)
• 30.000 ctm (14.16 m3/s)
•50.000 dm (23.6 mV<)
67.1 79.3
60
260
300
140
120
100 140 180 220
Distance from Stack (ft)
Figure 3. Stack height above top of intake required to meet a
specified design criterion for various exhaust volume flow rates at
a range of downwind distances
Fan Power Requirements — Design Q
(at4in.W.C.)
CommfcnalExhaust8tl.000Ipm
Coawntiooal Exhaust it 2,500 (pm
Coanntiaul Exhaust st 4,000 fpm
Wuwd-Arti * ,'
< 4 t * " ^ i - i i , *
• Is the site sufficiently complex to warrant a detailed wtnd-tunnel
' modeling evaluation? ,, ' *
• Do the laboratory exhausts have a high enough volume flow and
; exit velocity to escape the building envelope? , , ,,
Questions to ask when selecting a dispersion modeling consuttant
• Does the method you are using predict concentrations or dilution
, at building air intakes? « ' - _„• ,•
• Is your technique validated or conservative?
j ' i *j I "
• Do you utilize chemical emission rates in the analysis? • Sf
' • Does your method account for all wind conditions expected at '
typical induced-air systems and for a conventional system
at three different exit velocities. For the conventional
exhaust systems, the figure shows the benefit of decreas-
ing the exit velocity for a given design flow rate, always
assuming that the specified system meets the design goals.
To better understand the data presented in Figure 4,
consider the following example. A building exhaust system
requires 30,000 cfm at a static pressure of 4 in. water column
(W.C.) to adequately ventilate the building. An assessment
of the exhaust plume shows that a 10-ft-tall, 30,000-cfm
exhaust fan with a 2500-fpm exit velocity would meet the
design criterion established for the exhaust stack. Figure 4
shows that a conventional exhaust system meeting these
parameters requires fan power of approximately 27 bhp.
An equivalent induced-air system requires between 32 and
42 bhp to exhaust the same 30,000 cfm from the building,
an increase of 19% to 55%.
This discussion illustrates the importance of using
dispersion modeling to evaluate exhaust performance—
taking fan energy costs into consideration—to ensure that
acceptable air quality is achieved.
Summary and Conclusions
An accurate assessment of exhaust dispersion can be
used to produce exhaust/intake designs optimized for
energy consumption. No matter what type of exhaust sys-
tem is used, the important design parameters are physical
stack height, volume flow rate, exit velocity, expected pol-
lutant emission rates, and concentration levels at sensitive
locations. Whether conventional or induced-air exhaust
systems are used, the overall performance should be eval-
uated using the appropriate criterion that will ensure
acceptable concentrations at sensitive locations.
References
1. Fisk, W.J., "Review of Health and Productivity
Gains from Better IEQ," Proceedings of Healthy Buildings,
Vol. 4, pp. 23-34,2000.
2. Yates, A., "Quantifying the Business Benefits of
Sustainable Buildings (Draft)," Building Research
Establishment, Ltd., Project Report 203995,2001.
3. Kats, G., "The Costs and Financial Benefits of Green
Buildings," California's Sustainable Building Task Force,
Capital E, 2003.
4. Petersen, R.L., B.C. Cochran, and JJ. Carter,
"Specifying Exhaust and Intake Systems," ASHRAE
Journal, August 2002.
5. National Fire Protection Association (NFPA), Fire
Protection for Laboratories Using Chemicals. ANSI/NFPA
Standard 45-96,1996.
-------
8
LABS FOR THE 21ST CENTURY
6. ASHRAE, ASHRAE Handbook-HVAC Applications,
Chapter 44,2003.
7. International Code Council, Inc., International
Mechanical Code, 2003.
8. ANSI/AIHA, American National Standard for
Laboratory Ventilation, Standard Z9.5-2003,2003.
9. Petersen, R.L., J.J. Carter, and M.A. Ratdiff,
"Influence of Architectural Screens on Roof-top
Concentrations Due to Effluent from the Short Stacks,"
ASHRAE Transactions, Vol. 105, Part 1,1999.
10. Petersen, R.L., JJ. Carter, and J.W. LeCompte,
"Exhaust Contamination of Hidden vs. Visible Air
Intakes," ASHRAE Transactions, Vol. 110, Part 1,2004.
11. ACGIH, Guide to Occupational Exposure Values—
2003,2003.
12. ACGIH, 2002 Threshold Limit Values for Chemical
Substances and Physical Agents, 2003.
13. ACGIH, Odor Thresholds for Chemicals with
Established Occupational Health Standards, 1989.
14. EPA, Guideline for Use of Fluid Modeling of
Atmospheric Dispersion, April 1981.
15. Castro, I.P., "CFD for External Aerodynamics in
the Built Environment," The QNET-CFD Network
Newsletter, Vol. 2, No. 2, July 2003.
16. ASHRAE, ASHRAE Handbook-Fundamentals,
Chapter 27,2001.
17. ASHRAE, ASHRAE Handbook-Fundamentals,
Chapter 16,2001.
Laboratories for the 21 st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.labs21century.gov
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous Mum where energy is clean,
abundant, reliable, and affordable
www.eere.energy.gov
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
Acknowledgments
The following individuals contributed to the preparation
and publication of this guide to Modeling Exhaust Dispersion
for Specifying Acceptable Exhaust/Intake Designs:
Authors:
Ronald L. Petersen, Ph.D., CPP, Inc.
John J. Carter, M.S., CPP, Inc.
Brad C. Cochran, M.S., CPP, Inc.
Reviewers:
Michael A. Ratcliff, Ph.D., Rowan Williams Davies and
Irwin, Inc. (RWDI)
Thomas A. Scott, Ph.D., CPP, Inc.
Robert N. Meroney, Ph.D., Professor Emeritus,
Colorado State University
Scott Reynolds, P.E., Computer Aided Engineering
Solutions (CAES)
Otto Van Geet, P.E., NREL
Production:
Rene Howard, editor, NREL
Susan Sczepanski, graphic designer, NREL
For More Information
On Modeling Exhaust Dispersion for Specifying
Acceptable Exhaust/Intake Designs
Ronald L. Petersen, Ph.D.
CPP, Inc.
970-221-3371
rpetersen@cppwind.com
On Laboratories for the 21st Century:
DanAmon, P.E.
U.S. Environmental Protection Agency
202-564-7509 'l
amon.dan@epa.gov
WillLintner,P.E.
U.S. Department of Energy
Federal Energy Management Program
202-586-3120
william.lintner@ee.doe.gov
Best Practices Guides on the Web:
www.labs21cen tury.gov/ toolkit/bp_guide.htm
DOE/GO-102005-2104
May 2005
Printed wtth a renewable-source Ink an paper containing at least
50% wastepaper, including 20% postconsumer waste
-------
^
LABORATORIES FOR THE 21si CENTURY
BEST PRACTICES
This combined heat and
power system at the
Bristol-Myers Squibb
laboratory in Wallingford,
Connecticut, could meet
100% of the lab's power
requirement, if necessary.
ON-SITE POWER SYSTEMS FOR LABORATORIES
Introduction
Because of their unique requirements for lighting, ventilation, and equipment, laboratory buildings use a consider-
able amount of energy. The reliability of that energy is very important. Laboratories must be able to conduct research
without power interruptions, which can damage both equipment and experiments. Generating power and heat on site
is one good way to enhance reliability; it can also improve fuel utilization while trimming utility costs.
When should laboratory managers consider on-site power generation or combined heat and power systems for
their facilities? Some answers to that question are in the guidelines and "rules of thumb" presented here. Actual costs
and benefits for a particular facility can be determined through a detailed feasibility study.
" •
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
I"..
-------
LABS FOR THE 21ST CENTURY
This guide to on-site power systems is one in a series
on best practices for laboratories. It was produced by
Laboratories for the 21st Century ("Labs 21"), a joint pro-
gram of the U.S. Environmental Protection Agency and
the U.S. Department of Energy. Geared toward architects,
engineers, and facility managers, these guides provide
information about technologies and practices that can be
used to design, construct, and operate safe, sustainable,
high-performance laboratories.
Technology Description
On-site generation systems—also called distributed
generation (DG) systems—are small, modular, decentral-
ized, grid-connected, or off-grid energy systems. These
systems are located in or near the place where the energy
is used. They are also known as distributed energy or
distributed power systems. Although there is no textbook
definition yet for DG technologies, they are generally con-
sidered to be those that produce less than 50 megawatts
(MW) of power.
These systems can be installed on site to meet a vari-
ety of needs, such as for— ;
• High-quality, reliable power;
• Standby power, especially where utility-supplied
power is interrupted frequently or for long periods,
and where standby power is required for safety or
emergencies;
• Low-cost energy, where electricity or fuel costs (or both)
are high;
A rooftop photovoltaic (PV)
system produces electricity on
site at the Environmental
Protection Agency's facility in
Research Triangle Park, North
Carolina.
• Stand-alone or off-grid systems, where extending the
grid is too expensive or impractical;
• Peak shaving, where demand costs are high; or
• Combined heat and power (CHP), where thermal
energy can be used in addition to electricity.
Because they are installed close to the load, DG sys-
tems avoid some of the disadvantages of large, central
power plants, such as transmission and distribution losses
over long electric lines.
In CHP systems, two forms of useful energy—usually
electricity and heat—are generated simultaneously from
a single fuel source. Because CHP allows the waste heat
resulting from electricity production to offset a facility's
thermal energy needs, these systems are potentially
70%-85% efficient in utilizing fuels. The diagram on
page 3 illustrates this. The conventional approach to meet-
ing most facilities' energy requirements is to purchase
electricity from a central utility and generate heat sepa-
rately on site using a fossil-fuel-fired boiler. This approach
requires 72 more units of input energy to produce the
same 35 units of electricity and 50 units of heat that the
hypothetical CHP system produces. The inefficiencies of
the conventional approach are the result of— '
• Thermal inefficiencies in the
combustion process of the central generating plant;
• The inability to use the waste heat of the central gener-
ating plant (except in combined-cycle plants);
-------
LABS FOR THE 21ST CENTURY
Building Load
Conventional
Generation
Power
Plan) fuel
(113 units
remote energy)
Boiler fuel
(59 units
on-slte energy)
Combined Heat
and Power
Losses
Losses
In comparison to conventional generation, combined heat and power systems are more efficient.
CHPfuel
(100 units
on-site
energy)
*rrsn
fi
• Transmission and distribution losses from the central
generating plant to the load;
• Thermal inefficiencies of the on-site boiler.
Because they are located close to the load and allow
optimum use of waste heat, properly designed CHP
systems can be more than twice as efficient as the average
U.S. fossil-fuel power plant.
Laboratories in particular are excellent candidates for
CHP systems, for several reasons:
• Power interruptions or power quality problems
can have negative impacts on sensitive electronic
•' •• ,'TT.-- •••''<•:'. :Sumnwr!bSi^^ -f o;S5.';".i:'.V":--.-!i
" ',". ,.-.-. >(, i •'' <•'."! iv''i--'"V" . ".'•' ••.•«-j'1'•."7i*""'!"''"''. !ii;ii^:z;6'!5'jL!aJJis^ji"!i ^•r*^Mt8^'^*^^Ks*i:i^i'i,'.^',''.j,.j7"!.'! L.-. •.:...--''. t-v', a-.--'-*
• '. • •-''. ,,~i ,',;'• "A.,l '-• .':•!• .,'i-V" ;!'• •""jili'.-j. •'. V, F^f"^^ty|y^|i;^j',Xs»!'.JJV^.!i.!'3^S^.'^fej^!?88il rfi^ftiiljtife's^:'!:'
-------
LABS FOR THE 21ST CENTURY
equipment; an unexpected outage can undo months
of scientific work or damage important laboratory
specimens.
• Laboratories typically use more energy per square foot
than commercial facilities do; therefore, on-site genera-
tion can result in substantial energy cost savings.
• Laboratories tend to have a good mix of on-site thermal
and electric needs.
CHP can be more cost-effective in facilities that have
central heating systems, because much of the infrastruc-
ture needed for heat and power generation and use is
already there.
Several different technologies can be effective for
on-site generation. They include—
• Diesel, natural gas, and dual-fuel reciprocating engines;
• Combustion turbines and steam turbines;
• Microturbines;
• Fuel cells;
• Photovoltaics; and
• Wind turbines.
Energy storage technologies, such as batteries and
flywheels, often complement DG systems. Some systems
might need a fuel storage capability, as well. Thermally
activated technologies such as desiccant dehumidifiers,
service water heaters, and absorption chillers are also
possible components of a CHP system.
CHP systems—which can include reciprocating
engines, combustion or steam turbines, microturbines, or
fuel cells—may be the most appropriate on-site genera-
tion systems for laboratory facilities. However, photo-
voltaic systems and wind turbines can be a good choice
for electric-only applications in which the attributes of
renewable energy systems, such as reduced emissions, are
valued. Photovoltaics produce "green" energy from the
sun, operate quietly, and require little maintenance; they
can also be specially designed as an integral part of a
building's roof, wall, skylight, or other element, which is
known as building-integrated PV (BIPV). Wind turbines
can be appropriate where there is sufficient land area, an
adequate wind resource, and suitable laboratory siting
characteristics. The table on page 3 shows some perform-
ance characteristics of DG and CHP technologies.
For more information about DG and CHP, see Using
Distributed Energy Resources: A How-To Guide for Federal
Facility Managers, on the FEMP Web site (see also page 8).
A combined heat and power system at the U.S. Department of Agriculture's National Animal Disease Center, Ames, Iowa.
-------
LABS FOR THE 21ST CENTURY
-r-i i
Waste HeatUlilizatipn Optiohs
Waste Heal Temperature
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Design Considerations
When considering a DG or CHP project for your facili-
ty, always begin with a preliminary screening or scoping
audit to evaluate the proposed project's cost-effectiveness.
These are some design considerations to keep in mind
during your evaluation: .
• Minimize electric loads with energy-efficient equip-
ment and practices before implementing CHP or other
forms of on-site generation. This may allow you to
specify a smaller generator and minimize the capital
investment required for your DG or CHP project.
• Know your current utility costs, including energy
and demand costs; they help you determine whether
a DG or CHP system will be cost-effective at your
facility. Often, the "spark spread" between the cost of
electricity and the cost of natural gas determines cost-
effectiveness. But other impacts, such as power quality
and emissions, should also be taken into account. The
effect of the project on your facility's load profile must
be carefully evaluated for savings to be estimated
accurately.
• Consider anticipated changes in your facility's energy
requirements over the life of the DG or CHP system.
• Determine fuel costs and availability at your site; they
will help you decide which DG technologies and appli-
cations are most appropriate in your area. Complete a
fuel cost sensitivity analysis to see how changes in fuel
prices will affect the economics of the proposed system.
If possible, consider long-term gas contracts to reduce
the volatility of fuel costs over time; high fuel costs
combined with low electric rates make many forms
of DG uneconomical. In addition, fluctuations in gas
pressure, flow, and heating value must be considered in
regard to fueling DG and CHP systems.
Make your CHP system cost-effective by optimizing the
amount and use of waste heat. CHP systems are usual-
ly sized to accommodate the thermal energy needs of a
facility rather than the electric needs, but this is not a
hard-and-fast rule. To improve a project's economics, it
is important to consider every possible option for using
the waste heat, such as for space heating and cooling,
hot water, chilled water, steam, process needs, and
other uses. See the table on this page for more informa-
tion about using waste heat.
Know your local air quality requirements; they play
an important role in the selection of a technology for
a particular DG or CHP application. An "air permit"
may be required to construct, replace, and operate this
equipment. Permits can be costly and difficult to obtain
if they are not specified and planned for early in the
design process. Additional equipment, operations, and
material handling issues also need to be considered in
areas where tailpipe treatments are required to meet air
quality requirements.
> Investigate potential interconnection requirements
early in the project evaluation process, because they
vary from state to state and from utility to utility. It can
-------
LABS FOR THE 21ST CENTURY
be costly and time-consuming to delay finding out
about the requirements for interconnecting a DG sys-
tem to the local electric grid.
il • Become familiar with your utility's rate structures.
Utilities often have complicated rate structures with
I fixed charges, demand charges, block charges, and
time-of-use rates that can affect the economics of on-
site generation. For example, installing a CHP system
may allow you to purchase energy under "interruptible
rates" and thus save money. An interruptible rate is a
less expensive rate structure, which allows your utility
to interrupt your electric service for a brief time; during
that time, your facility's energy needs would be met by
your on-site generation system. On the other hand,
potentially costly backup or standby charges may be
imposed if you need electric service when your genera-
tor goes down for maintenance or repair. Not all utility
rate structures are designed to provide affordable
standby power service.
• Plan for adequate maintenance. On-site generation
requires additional maintenance. Is your current staff
capable of maintaining the new equipment? If not, con-
sider a post-installation maintenance contract that
ensures seamless operation and maintenance of the
" tij £ "ay *Jgjm S'S'f By mo si^?j a J J f|atlJi:T|
'^'"^^ ' -'
new equipment while providing training for on-site
staff to maintain equipment in the future.
Codes and Standards
In general, DG and CHP system installations are
subject to the same permitting and evaluation process as
other site or facility modifications. The National Electric
Code, the National Life-Safety Code, and the International
Fuel Gas, Plumbing, Mechanical, Building, and Fire Codes
are the key references for local code officials. For the most
part, these codes do not address some of the newer DG
technologies, such as microturbines and fuel cells. And
most code officials have little or no experience with issu-
ing permits for such installations. Therefore, code officials
may require a number of design, test, and documentation
reviews before approving a DG system.
Several standards authored by Underwriter's
Laboratories (UL), the National Fire Protection
Association (NFPA), and the Institute of Electrical and
Electronics Engineers (IEEE) specifically address the
installation of DG and CHP systems:
UL 2200 is a commonly cited reference for combustion
engines and gas turbines in stationary power applications.
It does not specifically refer to microturbines, but it could
be considered to include that technology.
NFPA 853, the Standard for the Installation of fuel
Cells, provides for the design, construction, and installa-
tion of fuel cell power plants with a capacity of more than
50 kilowatts. It covers natural gas and a number of other
fuel sources.
NFPA 3, the Standard for the Installation and Use of
Stationary Combustion Engines and Gas Turbines, works in
conjunction with UL 2200 to apply to the installation and
operation of these CHP technologies. Like UL2200, it can
be extended to microturbines.
IEEE 1547, the Standard for Distributed Resources
Interconnected with Electric Power Systems, addresses
technical requirements for the safe interconnection of DG
systems to the local electric distribution system.
Performance Examples
A variety of CHP projects are already operating suc-
cessfully at a number of laboratory facilities across the
country. Two good examples are a Bristol-Myers Squibb
laboratory in Wallingford, Connecticut, and the
Agricultural Research Service (ARS) National Animal
Disease Center (NADO in Ames, Iowa.
.. A,-* :.. t. i, - - *•• --> ??• - •>. u '• ••'
j-. ••JNw-felWK are irvMf^3BSlgn;siagfe;fe -A','^, •>'1 ^ "*j
• ' Swra: Oak Ridg'e!National laboratory'-:, •>"• 1 ='1.'"-••' r. '. f'"-'
LiIjL-*: ilijSi i!LLL™li^:l~^^
-------
LABS FOR THE 21ST CENTURY
Key Questions for DG7CHPJ S ;
Project Teams i \; !.;'--V«. t\'&:;r-r*:•!
,..',. i " ,'••,.-,,•;'';'•' -"!'•"• . ,.:'|;>",5>-K' Xi
Predesign . '• '^''L'f^^'.V,1. ^•s^^^'fj'-'^
. First; you might want to find out if .other facilities, in yipur area'^"?-. |.
' have installed nn-sitfi nRneratinn Finri thie nh'ntaiit oersSn at:r••;:-::-:^
''
.: • WhafwuldtheyhavedonBiffe>^^
.''•..- i-'^'.-V.-'-S^i' ^!^::y^&^^l^&^^^^
wesiigaiung opppnuniues TQ™^
many ''different specialists ^htlontractifi'd firrhsl'For.ihstarice/an' 1:~
i. „•* • ,, • -.' , , .. -•• v;t „!,,„„ sa; .1 „ " -^ ,i- ,v. ™,; -$;<<:;•„, j .,i-jf;is,*tH;geij:| ,— «,,^.-: , •
engineering lirrnls.usuatly hired/to pertormW.initi^^
study. DesjQri engineering dpcurnents^re;pu=t^
qualified 'A/Efirrri;.: '
• is usually 'responsible if or -building [t8sni::auitilK:{i?^;
' • How many^^DGibrCHP.systerns'fiayf you,awiprad^and/irj^-q
'. installed? What types of tecHnoiogies arid _what)sy«temI siffls%|
' have you worked with? . : ',-:- -''•;';' ^\;^:y!;;=S5;j;^'ik.
': -' i '•-",}."• . * ; ' !•#/•'•;" .y; Y<;'"i;?ji7ft;''l-.';.'!'.*^"W
, •;Haveyou^yetriad problemswithinterconniBcUng^p6.orCHP;i:
iRuclemc tn tho:riififl'> Ware theu ''Qhriiwsthrinfirs"9 «lf innt'- h'ri'w ^"
The 4.8-MW gas turbine system operating successful-
ly at the Bristol-Myers Squibb facility is a good model for
replication. Despite relatively low energy costs at the
site—about 7<(. per kilowatt-hour blended rate—the sys-
tem has a payback period of just 5 years. This is because
the project team paid close attention to steam loads at the
facility, considering the cooling side as well as the heating
side. By accounting for all the chiller plant loads and other
steam-driven equipment, they were able to optimize
waste heat utilization year-round for system economics.
Should utility power be lost, the CHP system with backup
generator sets can supply 100% of the facility's energy
needs. A knowledgeable facility engineer and project
manager—and reliable data—have been the keys to the
success of this installation.
The ARS N ADC in Ames is a major U.S. Department
of Agriculture center for research on livestock and poultry
diseases. A1.2-megawatt cogeneration system at the site
now provides highly reliable power and helps the N ADC
control utility costs in several ways. For example, by
generating power on site, NADC was able to purchase p
electricity at less expensive, interruptible rates.
Furthermore, the steam generated by using the waste heat
of the combustion process is a by-product that can be used
year-round for the thermal loads associated with steriliz-
ers, hot water, and wastewater pretreatment. Using the
technical resources and expertise of the unregulated sub-
sidiary of the serving utility—while designing, installing,
and interconnecting the CHP system—helped to make the
project a success. Because capital funds were limited, the
project was completed with financing through a "super"
energy savings performance contract coordinated by the
U.S. Department of Energy's Federal Energy Management
Program.
Conclusion
Installing an on-site generating system, such as
CHP, can be a good way to trim utility costs and enhance
energy reliability at laboratory facilities. Numerous siting,
permitting, and interconnection issues can be involved.
However, they do not need to be barriers for laboratories
that want to control costs, reduce environmental emis-
sions, enhance fuel efficiency, and ensure reliable heat and
power for sensitive equipment and important research
projects.
Acknowledgements
This best practices guide was written by Trina
Masepohl of the National Renewable Energy Laboratory
(NREL); it is based on information in the references and
in the Labs 21 case studies. The following individuals
provided very helpful review comments: Nancy Carlisle,
AIA; AH Jalalzadeh, Ph.D.; Andy Walker, Ph.D., P.E.; and
Otto Van Geet, P.E., NREL. We would also like to thank
Geoffrey Bell, P.E., and Paul Mathew, Ph.D., Lawrence
Berkeley National Laboratory, and Will Lintner, P.E.,
U.S. Department of Energy, for helpful reviews and
acknowledge the contributions of EPA; Dennis L. Jones,
P.E., USD A ARS National Animal Disease Center; and
Michael S. Conway, Bristol-Myers Squibb. Paula
Pitchford, editor, and Susan Sczepanski, graphic artist,
NREL, also contributed to this guide.
U S EPA Headquarters Library
' Mail Code 3404T
1200 Pennsylvania Avenue, NW
Washington DC 20460
202-566-0556
-------
8
For More Information
Borfaely, Anne-Marie, and Kreider, Jan R
Distributed Generation: The Power Paradigm for the
New Millennium. Boca Raton, FL: CRC Press, 2001.
U.S. Combined Heat and Power Association
(USCHPA) Website, www.nemw.org/uschpa/.
Accessed in April 2003.
US. Department of Energy, Distributed Energy
Resources Web site, www.eere.energy.gov/der.
Provides more information on the technologies and
applications of on-site distributed generation.
Accessed in April 2003.
U.S. Department of Energy, Federal Energy
Management Program, Distributed Energy
Resources Web pages at www.eere.energy.gov/
femp/. Accessed in April 2003.
U.S. Department of Energy, Federal Energy
Management Program, Using Distributed Energy
Resources, A How-To Guide for Federal Facility
Managers; see www.eere.energy.gov/femp/,
May 2002. Accessed in April 2003.
On Laboratories for the 21st Century:
PhilWirdzek
U.S. Environmental Protection Agency .
1200 Pennsylvania Ave., N.W.
Washington, DC 20460
202-564-2094
wirdzek.phil@epamail.epa.gov
Will Lintner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120
william.lintner@ee.doe.gov
On Distributed Energy Resources:
Trina Masepohl
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401-3393
303-384-7518
trina_masepohl@nrel.gov
, Laboratories for the 21st Century
\ U.S. Environmental Protection Agency
j? Office of Administration and Resources Management
/ www.epa.gov/labs21century/
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you s prosperous future where energy
is clean, abundant, reliable, and affordable
www.eere.energy.gov/
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
DOE/GO-102003-1773
December 2003
Printed with a renewable-source ink on paper containing at least
50% wastepaper, Including 20% postconsunw waste
-------
Laboratories for the 21st Century
Best Practices
WATER EFFICIENCY
GUIDE FOR
LABORATORIES
introduction
Most laboratory buildings in our country use
significantly more water per square foot than stan-
dard commercial buildings do, primarily to meet
their larger cooling and process loads. This greater
need also provides laboratories with more opportu-
nities to make cost-effective improvements in water
efficiency, especially with respect to the amount of
water they use in cooling towers and for special pro-
cess equipment. A laboratory's water efficiency can
also be improved by making a few changes in other
types of equipment, such as water treatment and
sterilizing systems, as described in this guide. And
alternative sources of water can often be effectively
integrated into a laboratory's operations.
This guide to water efficiency is one in a series
of best practices for laboratories. It was produced
by Laboratories for the 21st Century ("Labs 21"), a
joint program of the U.S. Environmental Protection
Agency (EPA) and the U.S. Department of Energy
(DOE). Geared toward architects, engineers, and
facility managers, these guides provide information
about technologies and practices to use in design-
ing, constructing, and operating safe, sustainable,
high-performance laboratories.
This exterior view of the Nidus Center for Scientific Enterprise in St. Louis,
Missouri, shows the cisterns that store rainwater used to irrigate the
grounds of this research facility.
rxEPA
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
-------
LABS FOR THE 21ST CENTURY
Laboratory Cooling Towers
Cooling towers, which are part of many laboratory
buildings, might represent the largest single opportunity
for greater water efficiency. This is because laboratories
usually have very large comfort-cooling and process
loads. Laboratories often use 100% outside air for ventila-
tion; this makes their comfort cooling loads higher than
those of most office buildings. Additional cooling is often
needed for special equipment such as lasers and electron
microscopes (see the section on laboratory equipment in
this guide). In fact, from 30% to 60% of all the water used
in multipurpose laboratories is for cooling.
Cooling towers use water in three ways: evaporation,
drift, and bleed-off. Figure 1 illustrates water use in a typi-
cal cooling tower. Evaporation (E) is fixed and controlled
by thermodynamics; about 2.4 gallons per minute (gpm)
of cooling water is used for every 100 tons of cooling.
Bleed-off (B) contains the concentrated, dissolved solids
and other material left behind from evaporation. Drift (D)
losses are typically a function of tower design. Most of
today's tower designs reduce drift to about 0.05% to 0.2%.
Since the amounts are small and they contain dissolved
solids, they are usually included in bleed-off. Make-up
(M) water replaces water lost because of E, B, or D.
Cooling Tower Water Management
The primary methods for managing water use in
cooling towers are operational ones. For example, cool-
ing towers can be investigated to see if there should be an
increase in the concentration ratio (CR) or cycles of con-
centration of water in the tower. The CR is an indication
of how many times water circulates in the tower before it •
is bled off and discharged. Increasing the recycle rate of
the tower reduces the consumption of make-up water and
l^^S^fff^^j^^^j^fWi^^a^^^j^fM
.e,. ,,
Since the CR represents the relationship between the concentration
of Dissolved solids in blee^off(CB) to the jconcentrationlnm
'«ssss^V«ife*«!*:srXi&^^
Typical Cooling Tower Operation j(.
Water flowing out of a cooling tower i '<
circulates to equipment that needs cooling. \ ' *'
The equipment is cooled; the water is ( y,
warmed. The warm water is returned to ) («<
the cooling tower where It is re-cooled \ )V
and the process begins again.
Drift ("D")
Evaporation ("E")
•»—Warm water
water f
("M") Treatment
chemicals
Cool water
f back to
Recirculating pump
Figure 1 . Water use in a typical cooling tower
(Source: New Mexico Office of the State Engineer 1 999; reprinted with
permission)
results in greater water efficiency (New Mexico Office of
the State Engineer 1999).
Figure 2 shows the effect of the CR on make-up water
use. Note that increasing the CR from 2 to 5 yields almost
85% of the savings that can be obtained by increasing the
cycles from 2 to 10. Increasing the cycling above 6 does
not significantly reduce make-up water use, but it does
increase the likelihood that deposits will form and cause •
fouling of the system (Puckorius 2002). Any of several
different parameters can be used to estimate the water
savings for a specific tower, as shown in the sample
calculation.
M 7000.0
6000.0
.
• qr|nal;co!ranjWtip|rrtto/fa::3:|;f f::.^.;;:; ;;?;r;; ;>;,.:"
Concentration ratio (CR)
Figure 2. Incremental water savings
In addition to savings on water and sewer costs, sav-
ings also result from having to purchase fewer chemicals
to treat the water. As the volume of incoming fresh water
is reduced, so is the amount of chemicals needed. Table 1
shows approximate savings on chemical usage resulting
from increasing the CR in a 10,000-gpm system.
Perhaps the best way to increase the cycles of concen-
tration is through better monitoring and management of
the water chemistry. The first step is to understand the
-------
LABS FOR THE 21ST CENTURY
Table 1. Chemical savings resulting
from increasing the concentration
ratio of a cooling tower
Cycles
Makeup
Chemical needed
fChange-
ifog
Source: GC3 Specialty Chemicals 2000. Service Document;
www.gc3.com/srvccntr/cycles.htm.
quality of the incoming water and what the controlling
parameter should be, such as hardness, silica, or total dis-
solved solids. There will be a relationship between these
parameters and conductivity, based on the water chemis-
try specific to a site. This relationship can help to establish
a conductivity set point. The conductivity controller opens
a blow-down valve as needed to maintain your control
parameter within acceptable limits.
Conductivity and flow meters should be installed
on make-up and bleed-off lines. Meters that display total
water use and current flow rate provide useful informa-
tion about the status of the tower and cooling system, so
they should be checked regularly to quickly identify prob-
lems. For example, the conductivity of make-up water and
bleed-off can be compared with the ratio of bleed-off flow
to make-up flow. If both ratios are not about the same,
the tower should be checked for leaks or other unwanted
draw-offs.
It is important to select a chemical treatment vendor
carefully—one who understands that water efficiency
is a high priority. Vendors should provide estimates of
the quantities and costs of treatment chemicals, bleed-off
water volumes, and expected CR. Criteria for selecting a
vendor should include the estimated cost of treating 1000
gallons of make-up water and the highest recommended
cycle of concentration for the water system.
New construction and renovation projects are excel-
lent opportunities to design for greater water efficiency. A
plume abatement or hybrid tower is one design that can
have an impact on water use, even if the primary reason
for it is to reduce the visible plume* emanating from large
industrial towers. A smaller plume is desirable in many
residential areas and in areas where visibility is important,
such as near airport runways.
* A plume is the visible column of saturated air exiting a
conventional cooling tower.
Hybrid towers have both a wet and a dry cooling sec-
tion (Figure 3). The tower can be run in wet mode in the
summer, when the plume is less problematic, at the high-
est efficiency. In winter, the tower can be run in either dry
or wet/dry mode. When operating in this mode, the dry
section warms the exit air stream to raise the temperature
above the dew point of the surrounding air, reducing
humidity and thus the size of the plume.
Hybrid cooling tower performance depends on the
location and environmental characteristics of the site.
Energy and water costs also play a crucial role in the deci-
sion to use hybrid cooling towers, because making some
of these towers more water-efficient could have a negative
impact on energy efficiency.
Another option for new and retrofitted cooling tower
designs is to pipe blow-down water to a storage tank.
This water can then be reused for nonpotable needs, such
as bathroom commodes or fire suppression systems.
Facilities should exercise caution when using blow-down
water, however, as it can be extremely high in dissolved
solids as well as chemical by-products from the water •
treatment process. The quality of blow-down water
should be checked to make sure that it will not dog, foul,
or otherwise damage other systems.
Special Water-Efficient Features
Special features of towers and water systems that
promote water efficiency include side-stream filtration,
sunlight covers, alternative water treatment systems, and
automated chemical feed systems.
V Air 4
\ out /
Dry
section \
Air
in
Hot
water —
in
Air
in
vH
Wet/
section
a
Airflow
"control louvers'
Mixing chamber
Dampers
- w ^
&£ v!
^^is^w^^^toiRsasfiS'iss^y^SStte:^
.Air
" In
Hot
-water
in
Air
" in
Cold
Figure 3, A hybrid cooling tower
Source: EPRI and CEC 2002.
-------
LABS FOR THE 21ST CENTURY
Side-stream filtration systems deanse the water with
a rapid sand filter or high-efficiency cartridge filter. These
systems increase water efficiency and use fewer chemicals
because they draw water from the sump, filter out sedi-
ment, and return filtered water to the tower. Side-stream
filtration is particularly helpful for systems that are subject
to dusty atmospheric conditions.
Sunlight covers can reduce the amount of sunlight
(and thus heat) on a tower's surface. They can also signifi-
cantly reduce biological growth, such as algae.
Alternative water treatment options, such as ozona-
tion or ionization, can reduce water and chemical usage.
Such systems can have an impact on energy costs, how-
ever, so managers should carefully consider their life-cycle
cost.
Automated chemical feeds should be installed on
cooling tower systems larger than 100 tons. An automated
feed system controls bleed-off by conductivity and adds
chemicals according to the make-up water flow. Such
systems minimize water and chemical use while optimiz-
ing the control of scale, corrosion, and biological growth
(Vickers2002).
Laboratory Process Equipment
Three broad areas in which the water efficiency of
a wide range of laboratory process equipment can be
improved are cooling of equipment, rinsing, and flow con-
trol. These areas can be addressed individually or together
to increase the water efficiency of most laboratories.
Equipment Cooling
Single-pass cooling typically consumes more water
than any other cooling method in laboratories. In single-
pass or once-through cooling systems, water is circulated
once through a piece of equipment and then discharged to
a sewer. Single-pass systems use approximately 40 times
more water than a cooling tower operating at 5 cycles of
concentration to remove the same heat load.
The equipment typically associated with single-pass
cooling are CAT scanners, degreasers, hydraulic equip-
ment, condensers, air compressors, welding machines,
vacuum pumps, ice machines, X-ray equipment, air con-
ditioners, process chillers, electron microscopes, gas chro-
matographs, and mass spectrometers. Sometimes, research
staff members order and install these and other types of
equipment that require cooling without consulting facility
management. The equipment is usually connected directly
to a public water supply, and it drains to a sewer.
The best way to combat the water waste associated
with single-pass cooling is to use a process or cooling
loop. This loop provides water at a preset temperature to
cool researchers' equipment. A small packaged chiller or
central plant towers can reject the heat from these systems.
Other efficient options include reusing single-pass
discharge water for irrigation or initial rinses, or for recov-
ering the heat from one process for use in another.
Often, the equipment in this category is used only
intermittently. So, it can be quite difficult to determine
how much of a laboratory's total water use goes to process
equipment. A water meter on the process loop can provide
this kind of information. By separating laboratory water
from domestic, irrigation, or other cooling water, facil-
ity managers can better monitor water quality and usage '
across the whole facility.
The more complicated equipment used in today's lab-
oratories often requires tighter or more stable temperature
control (or both) than a centralized system can provide.
Small packaged chillers allow this control and reduce
water usage. Such chiller systems consist of a compressor,
condenser, evaporator, pump, and temperature control-
ler in one small package. The packaged unit recirculates
temperature-controlled fluid to a laboratory application
to remove heat and maintain a constant temperature. The
recirculating fluid picks up heat from the application and
returns to the chiller to be cooled to a specified set point
before circulating back to the application.
Packaged chillers work in somewhat the same way
that large comfort-load chillers do. Laboratory managers
may want to compare the amount of energy used by dif-
ferent packaged chillers at both part and full loads, and
select the most efficient one that meets their needs.
Removing the chiller's heat can be done by rejecting
the heat to either air or water. If an air-cooled condenser is
used, it is better to use a design that rejects heat to the out-
side air rather than to conditioned laboratory space. The
second option would increase inside temperatures and the
amount of energy needed for space conditioning. An alter-
native is to reject the heat to water (Krupnick 2000).
• In this case, the cooling water should be recirculated
chilled water, or recirculated through a cooling tower.
Using once-through cooling water for this purpose is not
recommended.
Equipment Used in Rinsing
Rinsing equipment can often be made more efficient,
A counter-current rinsing operation is typically the most
efficient method (Figure 4). In counter-current rinsing, the
flow of rinse water is opposite to that of the workflow. The
basic premise is to use the cleanest water only for the final
or last stages of a rinse operation; water for early rinsing
tasks, when the quality of the rinse water is not as impor-
tant, is obtained later in the process. Other efficient rinsing
-------
LABS FOR THE 21ST CENTURY
Workflow
Third rinse
tank
Second rinse
tank
First rinse
tank
Rinsewater
out
Figure 4, Schematic diagram of counter-current rinsing process
(Source: New Mexico Office of the State Engineer 1999; reprinted with
permission)
options include batch processing, in which several pieces
are cleaned at the same time, and using rinses from one
process in another one.
Flow Control
Many pieces of lab equipment are "on" continuously,
even when the process runs only a few hours per day or
a few days per year. Often, the water flow to some of this
equipment is only a few gallons per minute. However, a
continuous 1.5-gpm trickle flow through a small cooling
unit adds up to 788,400 gallons per year.
Using a control or solenoid valve in these applications
allows water to flow only when the unit is being used.
Another option is to use shut-off valves or timers to turn
equipment off after normal working hours and when a
process is shut down for maintenance or other reasons.
Laboratory Specific Best Practices
Water efficiency is an important consideration not
only for special process equipment but in other lab equip-
ment, as well. This includes equipment used in laboratory
water treatment, sterilization, photographic, X-ray, and
vacuum systems.
Water-Treatment Equipment
In their day-to-day operations, many laboratories
require high-quality water or water free from mineral and
organic contaminants. There are five basic levels of sepa-
ration processes: particle filtration, micronltration, ultra-
filtration, nanofiltratioa and hyperfiltration. A nitration
spectrum (see www.gewater.com/library/ ) illustrates
the separation process and size range for common types
of materials. Typically, as finer and finer particles are
removed, energy use and water waste increase. Therefore,
facility managers will want to choose a nitration process
that matches their requirements. For example, reverse
osmosis (RO) water should be used only in processes that
require very pure water. Because RO produces the purest
water, it usually requires the most energy and materials
and results in the most waste.
Two streams exit the RO system: the concentrate
stream and filtered, purified water. The concentrate is
rejected water containing a high level of dissolved miner-
als. The concentrate is then typically sent to a drain, or a
portion of it is recycled back to the feed stream to increase
the system's overall water recovery. Although the concen-
trate is high in dissolved minerals, it can be reused in non-
potable applications (e.g., in bathroom commodes) (See
Figure 5). However, as with cooling tower blow-down,
water quality should be monitored to avoid fouling other
systems. The recovery rate (i.e., the ratio of the filtered
purified water to the volume of feed water) is typically
50% to 75% for a conventional RO system operating on
city feed water.
Disinfection/Sterilization Systems
Two types of systems are used for disinfection in labo-
ratories: sterilizers and autoclaves. Sterilizers use water
to produce and cool steam and to cool wastewater before
discharge. Some units also use water to draw a vacuum
to expedite the drying process. Water use in sterilizers
ranges from 1 to 3 gpm. Autoclaves use ethylene oxide as
the sterilizing medium rather than steam. Water is used to
ipi"e-r«i..itf*ho'SainYofithiBiwater.supplysforS period pMimelp«S
&4*SM,Nw~ifS»«s
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!.NS so ds (TDS) (see a so.wviraf.epa:gov/safewaterOKNoteihat«li3;S'i
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-------
LABS FOR THE 21ST CENTURY
1 R|i^|pH;^c^i?t^;.^
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«§• Purchase newequipment only if it is designed toreeirculatepp «Mi
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fess Adjust flow rates to the minimum ones recommended by,the.;;K3;;';;
WSIjS&t&l®*®!****^^
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I'jjsi^iWSSSSK^a^WiifiAiiRKy^Sw^
. Check with the manufecfairento make =
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• Replace older.equipment.wrth newer, more efficient models. Look
;Wsss:^^HJ^agfS»fe5^s^^^>qK^4gai!Ki!Sai8?^BSK!r'a?SE's's:'-33
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eliminates the need for chemicals used in photographic
processing.
Vacuum Systems
Wet chemical laboratories often employ faucet-based
aspirators to create a venturi-type siphon, used as a vacu-
um source. These systems can apply a vacuum to laborato-
ry filtration systems for extended periods of time. A better
approach would be to install a laboratory vacuum system
or to employ small electric vacuum pumps to create the
pressure differentials necessary for vacuum applications.
Dishwashers
Laboratory dishwasher systems use deionized or RO
water to deliver water of different qualities in the rinse
cycles. They are designed to remove chemical build-up
on glassware/pipettes, and other types of equipment.
Newer dishwashers use less water than older mod-
els. With newer models, the operator can also select the
number of rinse cycles. Fewer cycles should be selected
whenever possible, if that will not affect the quality of the
product/
Vivariums
Vivariums use equipment and practices specific to
animal care, such as automatic animal watering systems.
These can consume large volumes of water because of
-------
LABS FOR THE 21ST CENTURY
the need for constant flows and frequent flushing cycles.
If it is properly sterilized, this water can be retirculated
in the watering system rather than discharged to drains.
Where this water cannot be recycled for drinking because
of purity concerns, if it is sterilized, it is still likely to be
acceptable for other purposes, such as cooling water
make-up, or for cleaning cage racks and washing down
animal rooms.
It is also possible to reduce the amount of water used
for some process equipment (e.g., cage washers and steril-
izers) in laboratory vivariums. For example, small cages
are typically cleaned in a tunnel washer; laboratories
could reuse the final rinse water from one cage-washing
cycle in earlier rinses in the next washing cycle, by making
use of a counter-current flow system.
Alternative Water Sources
Large facilities, such as laboratory buildings, are
good candidates for alternative, or unconventional, water
sources because they usually use a large amount of non-
potable water. This section describes some ways that facil-
ities can greatly increase their total water supply without
adding capacity from the public system or well.
The two most useful water sources for laboratory
buildings are air-conditioning condensate recovery and
rainwater harvesting. Both can provide fairly steady
sources of relatively pure water; they are limited primar-
ily by the cost of capturing the water. Another source is
reclaimed effluent from wastewater treatment plants.
Utilities often supply this kind of water at reduced prices.
Condensate Recovery
In many places in the United States, mechanical space
conditioning generates significant quantities of conden-
sate, as warm humid air is cooled and dried for tem-
perature and humidity control. The condensate from air
conditioners, dehumidifiers, and refrigeration units can
provide facilities with a steady supply of relatively pure
water for many processes. Laboratories are excellent sites
for this technology because they typically require dehu-
midification of a large amount of 100% outside air.
The potential for condensate recovery depends on
many factors, such as ambient temperature, humidity,
load factor, equipment, and size. However, because this
technique is relatively new, there are no established for-
mulas for calculating the exact amount that can be
collected from a given system.
Condensate water is relatively free of minerals and
other solids. In most cases, it is similar in quality to dis-
tilled water. This makes it an excellent source for cooling
tower or boiler make-up and RO feed water, for example.
Another advantage of using condensate for cooling tower
make-up is that there is usually a good seasonal cor-
relation between condensate supply and cooling tower
demand. Additional savings could result from reduced
chemical usage and lower membrane maintenance costs,
Figure 5 (next page) illustrates how water from several
sources, including AC condensate, can be piped into one
storage tank for reuse in nonpotable water applications.
Condensate should not be considered potable because
it can contain dissolved contaminants and bacteria.
However, because biocide is added to cooling towers,
condensate is an excellent option for cooling tower make-
up. For laboratories that are not medical or bacteriological
research facilities, condensate should be safe to use for
drip-type irrigation. However, medical and other facilities
could use disinfected condensate in spray-type irrigation.
Normal chlorine feed equipment, ozone, or ultraviolet dis-
infection should be effective. It is best to use condensate
in a process that provides an additional level of biological
treatment (Hoffman).
Rainwater Harvesting
Rainwater is another excellent source of nonpotable
water. It can be used in many of the applications in which
condensate recovery water is used. Typically, however,
rainwater contains fewer impurities than potable water
^
fc-^Wif:^^
s The cities of San Antonio and Austin^Texasideveloped some rules;;,
p5iSH-««»&ig»«;S"»^^^^
of thumb tharcan be used anywhere for condensate recover^ifii
................. ~ .......................
systems that are working,well in their parUcuIancllmateslBy,,
i:mawr«.^i?fa«»;ipe^^
observnginsta ed$ystems;:they-foundthatfrom:01ito.0>3ga on
lafgetyassociatedjWrth levels of ambient humidity. For example,
. ,
Oiey could assume OHfgallonwpultl be produced at a humidity of
oof average load
-------
8
LABS FOR THE 21ST CENTURY
s^^S'^^M^nfS^m^i^W^^m\^-j
S^3^j&dsRv.«J^^|^;s3*:^^&;i^
!cffiiWCTisV53;376tfthioh^
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drains; leaf screens and roof washers that remove debris
and contaminants; cisterns or storage tanks; a conveyance
system; and a treatment system. Leaf screens are effective
in removing large debris from the system.
The storage tank or cistern is the most costly element.
It can be either above or below ground, but close to supply
and demand points to minimize piping needs. It should
have a tight-fitting lid to prevent evaporation and to keep
out mosquitoes, animals, and sunlight (which allows algae
to grow).
Laboratories considering the use of rainwater should
check with local or state governments about possible
restrictions. Many states, particularly those in the West
restrict rainwater use. The restrictions have to do with
water rights laws, which are complex and vary according
to the jurisdiction. Some allow facilities to detain water for
irrigation and other uses that return the water back to the
system, but they do not allow water to be retained perma-
nently on a site.
Rain water
A/C condensate
Tower
blowdown
from a public drinking water supply. The only cost is the
capital cost of equipment to collect and store the water
(which can be significant). Storm water from other imper-
vious surfaces besides rooftops can also be collected.
However, because storm water is not as high in quality
as rooftop rainwater, it is best to use storm water only for
irrigation.
Rainwater systems typically consist of six elements:
the roof or catchment area; gutters, downspouts, or roof
Float switch
to potable
water valve
Overflow
drain to
stormwater
system
Potable
water
supply
To fire supression
system
To nonpotable
uses
Figure 5. Nonpotable Water Collection and Reuse
-------
LABS FOR THE 21ST CENTURY
rwjf or catchment area. The average rainfall for a srte can b^iis^
^-".•s&ii^irrffcfqifijj^ii&fii;^^ ?s£E "-&'$?• 33
obtained from National Weather Service data; Because of seasoriarj 5
"•"'•'•"""««»8SgPP^^
atorchnnlri ho rnnciriorori intormc nf uariohlo*- I
•*:a:''!S!WKSn'M«l>S!g!8SWS^^
collection range; use average rainfall as a maximum and half theirs
:i:-'K>!:H*!^te|HSi;ir*iBSS3^
average rainfall as a minimum^ to represent drought conditions. The
«LkS3j.S8p;:|g«S!f:jSgt5»»S^
:•: jknm»ww I •*•**<>•«**» !•.' *** CM|I«*»M •! ' l«.j^k« —* '««» ^I«.U«4t A_~A«- 4 -__»•.«_.*. ;;•;,~ •
The collection efflcpcydepends:ons^
retention; Th^
*r.:;S%agH>iS3jpt:!?te^^
more impervious the roof surface, the more high-quality water can
.•ViiSKfexsWiS^ii*^^
; be collected. Pitched metal roofs lose negligible amounts c-f water. '4
:h;;H;"':-^£;£;f!&ii^!c?i^Sj~s&^i3i^^^
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tar and gravel roofs lose as much as 15%. Flat roofs can retain as Infers
T5-":J:^p;5£i£!Ss*!;;|
•->';A;;:];r?v^'f::>'X^^?'^<£-'.'K^
: and some water can be lost to overflow. So, many Installers assume ;«
...... ..._ ,.,,,*.,, •^!^;-;r^;;;:;i^^T^^;-c-^.f<^;Hr^^^:^^;;:.1:^s;:^:aJj;!i^a;!!^?:^M'^f';sr^:;;[r;il
fefficiencies between 75% and 90% (Texas Water Boart 1997). |:|f;;
jV^-V-^HHi^J/^BlfeSiip^;^*'*^
Rainwater and condensate recovery systems can be
expensive to install as retrofits. Storage capacity in partic-
ular is expensive. However, properly sizing the system to
match demand to supply could greatly reduce costs. The
real value of these systems comes from the high quality of
water they provide.
A laboratory complex in Washington, D.C., provides
a hypothetical example of rainwater harvesting. The site
receives an average of 43 inches of precipitation each year.
The complex has a roof area of 54,000 ft2. With a collection
efficiency of only 75%, the facility could capture about
1,085,477 gallons of rainwater annually. The site would
save on both water and sewer fees if water normally
drains to the sewer. Using a pricing rate similar to those in
the condensate recovery example, this system would save
$5,970 per year in water costs.
Reclaimed Wastewater
Reclaimed wastewater is an option in limited cir-
cumstances, when a laboratory has access to municipal
wastewater that has been treated to a secondary disinfec-
tion level or when treated wastewater can be generated
cost effectively on site. Reclaimed wastewater might be
used for some nonpotable applications, such as cooling
tower make-up. An example is the Nicholas C. Metropolis
Modeling and Simulation Center at Los Alamos National
Laboratory (LANL) in New Mexico. The center uses treat-
ed wastewater from the LANL complex for cooling tower
applications.
The EPA regulates wastewater discharge but does
not regulate water reuse applications or quality. There are
uniform national requirements only for biological oxygen
demand, total suspended solids, and pH. The National
Pollutant Discharge Elimination System (NPDES) regu-
lates all other contaminants by region and body of water.
Design Considerations
One of the most important ways to begin using water
more efficiently is to create a water balance. A water bal-
ance shows the sources and uses of water on a site. It can
be very detailed or cover only major uses; it can show
usage at the whole site or in certain buildings or opera-
tions. The objective is to show where and how water is
being used, what the sources are, and how much water
is being disposed of. In new facilities, a balance can help
designers plan equipment layouts and identify opportuni-
ties for greater efficiency. In existing facilities, it can help
laboratory managers identify leaks,'other losses, and pos-
sible misuses. Although it is not possible to account for
every drop, well-managed facilities can usually account
for 85%-957o of the water they purchase.
Creating a Water Balance
The first step is to document all major water-using
equipment and processes at the site and usage amounts.
The water quality required for each use can also be includ-
ed, as well as information about the local climate, such
as monthly averages for evapotranspiration rate, relative
humidity, temperature, and precipitation.
j^W|f«^^
tpujrieftiafcesli/i^^
•^;r=:«i^iSp&yia;ii;tei.L!!3£=iSS'SS8s-S-!:,;;.;= ^Stfl&^vibs rKA;»r;>i."\ -V 1 "-I
1\* Check grounds and facilities for obvious water or steam leaks InS i
'.•K"--it"Vi,%S*'Z$~$%:zrl ".Zt.'.-^'^-"'^^^'''*:-"-'"-"'-& " 1: •;:v^;:2;:x!:^;;")ic^«:.. :• .:; „. 1
" ''' '
ivi''j»t- '«"«iJ'"^"1"!J • • ~''t*""3'w':"i'"%™J°» ~~i~ i"*wi'1r~~*^~.c-f3f; «.'•;• >.";•.; s.sar" i.^j^.-. •»
• Check the main water meter at night and again .in the morning to £
=a fefe';at»f ji^«8=»K* w
-^i'. CAfi'ir Tnnm.'«o'4 l4*/iA ammin* «t* I»nBt*«lQinA*l iiA'kMn 4kn* l*\rt\rti+nf* *r
::V:'^'s^jjeiihj;—'^^^-^S^^^-^1^'^^)^'^-^!*^'*^^"^''^^;^1^!^-!^^';.;"!^—..:,',: '•
••-•i:-: usflriiif actual usaae'is Kidher.than'nriainat MsHmatBs^yfiSS; ~f:'••'• ~i
-.!
Sx used, if actual usage is higher than original estimates.;
• ^:^::ri;j£'f;;;;h:,!;,;;-'"-^J;."«::^!",Vf"'^.^ ":"::!•; '•; 'vlk " "•'h'::.-;".",;'"'5':!"' -•ir!;:/ !./ '.',".'•
]
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-------
10
LABS FOR THE 21ST CENTURY
ttftttft
Lawn/grounds
irrigation
tUtttH
Lawn/grounds
irrigation
Before Construction
Sewer
After Construction
Sewer
Figure 6. The diagrams show how water efficiency measures at an Intel plant in Rio Rancho, New Mexico, have changed the way in which
water flows through the facility (UPW - ultra-pure water; FAB - fabrication plant; AWN - acid waste neutralization facility).
(Source: New Mexico Office of the State Engineer 1999; reprinted with permission)
The second step is to determine whether known pur-
chases equal known usage. If these two are in balance, the
next step is to look for opportunities for greater efficiency
in each major usage category and determine whether
water from one process can be used elsewhere cost
effectively. If purchases and usage do not balance, how-
ever, more investigation is needed. Often, the chief cul-
prit is a lack of information. A thorough review can help
laboratory managers fill in any missing information and
discover the source of the imbalance.
Figure 6 shows a water balance for a microprocessor
plant near Albuquerque, New Mexico. By rethinking the
water quality needs of certain applications, plant staff
were able to use water discharges from one process for a
number of others. For example, reject water from ultra-
pure water systems can be used to irrigate the grounds.
Ultra-pure water discharged from fabrication processes is
clean enough for use in cooling towers and exhaust scrub-
bers. The company also implemented a number of efficien-
cy measures within the plant to make better use of water.
The plant has been able to maintain water use at about 4
million gallons per day despite an increase in production
of 70% (New Mexico Office of the State Engineer 1999).
Design Planning
Laboratory designers will want to consider water uses
and sources early in the design process. The following list
shows where each topic discussed in this guide should be
addressed in the design process.
During the Schematic Design Phase
• Identify appropriate alternative water sources.
• Locate collection or storage areas.
• For multibuilding campuses, design the building lay-
out to reduce the size of the distribution system.
• Include a process or cooling loop for all equipment.
• Include a vacuum system.
• Include condensate and chilled water return systems.
During the Design Development Phase
• Identify any processes that can use water from other
processes or that can supply water to processes.
• Meter all major water-using processes.
• Select equipment with water-saving features.
Conclusion
Because laboratories need more water to meet process
and cooling loads, among other requirements, they usual-
ly use much more water per square foot than conventional
commercial buildings do. However, this greater usage
also provides laboratories with significant opportunities
to reduce their total water use by making cost-effective
improvements wherever possible. Many government
agencies and organizations—such as the DOE Federal
Energy Management Program, the EPA, and the American
Water Works Association—have published guidelines and
recommendations on water efficiency for industrial, com-
mercial, and laboratory buildings. These water efficiency
guidelines can help you use less water today to ensure
that the nation will have safe, secure supplies tomorrow.
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LABS FOR THE 21ST CENTURY
11
References
American Water Works Association (AWWA). 1993.
Helping Businesses Manage Water Use: A Guide for Water
Utilities. Denver, CO: AWWA.
Electric Power Research Institute (EPRI) and
California Energy Commission (CEC). 2002. Comparison
of Alternate Cooling Technologies for California Power
.Plants: Economic, Environmental, and Other Tradeoffs.
Palo Alto, CA: EPRI; Sacramento, CA: CEC. Available
atwww.energy.ca.gov/reports/2002-07-09_500-02-
079F.PDF. Accessed August 2004.
Federal Energy Management Program. June 2004.
Saving Energy, Water and Money with Efficient Water
Treatment Technologies, A FEMPTechnology Focus. DOE/
EE-0294. Washington, DC: U.S. Department of Energy.
Hoffman, Bill. Coordinator—Commercial Industrial
Programs, City of Austin, TX, water department.
Krupnick, Stu. July 2000. "Realizing Chillers'
Capabilities in Laboratories." Process Cooling and
Equipment, A Supplement to Process Heating Magazine.
Available online at www.process-cooling.com/CDA/
Articlelnformation/features/BNP Features Item/
0,3674,7515,00.html. Accessed August 2004.
New Mexico Office of the State Engineer. July 1999.
A Water Conservation Guide for Commercial, Institutional
and Industrial Users. Albuquerque, NM: Office of the
State Engineer. Available online at www.seo.state.nm.us/
water-info/conservation/pdf-manuals/cii-users-guide.
pdf. Accessed August 2004.
New York City Department of Environmental
Protection. 2003. New York City Drinking Water Supply
and Quality Report. Available online at www.nyc.gov/
html/ dep/ pdf / wsstat03.pdf. Accessed August 2004.
Puckorius, Paul. November 2002. "Water
Conservation Via Optimizing Water Use." Process
Cooling and Equipment, A Supplement to Process Heating
Magazine. Available online at www.process-cooling.
com / CD A/ Articlemf ormation/ Water_Works_Item /
0,3677,87663,00.html. Accessed August 2004.
Tanner, Stephanie, Eva Urbatsch, and Anna
Hoenmanns. 2003. Water Efficiency Plan. Internal
Publication. Golden, CO: National Renewable Energy
Laboratory.
Texas Water Development Board. 1997. Texas Guide
to Rainwater Harvesting, Second Edition. Austin: Texas
Water Development Board.
Van Gelder, Roger E. 2004. "Field Evaluation of Three
Models of Water Conservation Kits for Sterilizer Trap
Cooling at University of Washington." Presented at the
2004 Water Sources Conference & Exposition, January
11-14, Austin, Texas.
Vickers, Amy. 2001. Handbook of Water Use and
Conservation. Amherst, MA: Water Plow Press. .
Wilcut, Eddie, and Brian Lillibridge. 2004.
"Condensate 101—Calculations and Applications."
Presented at the 2004 Water Sources Conference &
Exposition, January 11-14, Austin, Texas.
Additional Resources
Federal Energy Management Program. Best
Management Practices for Water Conservation at Federal
Facilities. Washington, DC: U.S. Department of Energy.
Available online at www.eere.energy.gov/femp/
technologies/water_fedrequire.cfm. Accessed August
2004.
North Carolina Department of Environment and
Natural Resources' Division of Pollution Prevention
and Environmental Assistance, Water Efficiency: Water
Management Options. Available online at http:/ /
www.p2pays.org/ref/04/03101.pdf. Accessed September
2004.
U.S. Department of Defense. Military Handbook
• 1165: Water Conservation. Washington, DC: DoD, 7 April
1997. Available online at https:/ /energy.navy.mil/
publications/ water/mil_hdbk_1165.pdf. Accessed
August 2004.
Acknowledgments
Stephanie Tanner was the principal author of this
publication. The author wishes to thank Bill Hoffman, City
of Austin Water Department, for information on rainwa-
ter harvesting and A/C condensate recovery, and James
Kohl, URS Corp., for initial research. Roy Sieber of ERG
and Otto Van Geet, P.E., Nancy Carlisle, A.I.A, and Sheila
Hayter, P.E., all of NREL, provided helpful comments and
peer reviews. Paula Pitchford and Susan Sczepanski of
NREL provided editing and graphic design.
-------
1.2
For More Information
On Water-Efficient Laboratories:
Stephanie Tanner
National Renewable Energy Laboratory
901D Street, S.W., Suite 930
Washington, D.C. 20024
202-646-5218
stephanie_tanner@nrel .gov
On Laboratories for the 21st Century:
Dan Amon
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W. (mail code 3204R)
Washington, DC 20460
202-564-7509
amon. dan@epa.gov
Will Lintner
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120
william.lintner@ee.doe.gov
Best Practices on the Web:
www.labs21century.gov
Laboratories for the 21 st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.labs21 century.gov
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous future where energy Is clean, abundant,
reliable, and affordable
www.eere.energy.gov
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
DOE/GO-102005-2008
May 2005
Printed with a renewable-source Ink on paper containing at least
50% wastepaper, Including 20% postconsumer waste
-------
LABORATORIES FOR THE 21sT CENTURY
CASE STUDIES
Case Study Index
Laboratory Type;\:f ,\
.-if Wet lab-. .'•.••*•.•;:,-^ ;-':.s
HIT Dry lab >
Q'Clean room; ;,:,..£
" Construction Type .('. ;>.,; jlj
Retrofit .'•' :•; .^'y^/;
• Q: Manufacturing;? ?:'-"-_: -. r 'I
if teaching.-/'.: :--' •'•"{'"
if Chemistry • •'-•;:.:"';: r.:
-V-Biology i • • ;;•_•>..'.., 1
Q Electronics '; -; '" \
Service Option- • -' ' fj
If Suspended cejllng ,v -: i
•Q Utility service corridor,; |
Q Interstitial space /;,.«
FeaturedTechnologies
0^Fumei hoods :. ' ' ,
BfContrals/T/:-.,-'^ -- j
if Mechaniciil systems ' ,ij
If Electrical loads^^* j
if Water conservation, '.•[ 'j
' la'.Renewables-1 ; „ :-"- ":j
;ISfS'ustainabie'. \-^:^t.f ..s|
. •design/planning / 1
a Onrsite generation /' \ M
.OifpayligWing .:.-•...'-,'; :1
a*' Building commissioning. |
Other Topics :'.'v '
•Q Diversity factors_.. ,
Q Carbon trading; -.• .
Hi? O Selling concepts to
13 . • .stakeholders- r '' v: j
LEED Rating:
af Platinum
DONALD BREN HALL,
SANTA BARBARA, CALIFORNIA
introduction
The Donald Bren School of Environmental Science & Management at the University of
California, Santa Barbara (UCSB) "walks the talk" and exemplifies its mission. Because of its many
energy-efficient and environmentally sound features, Donald Bren Hall has received a Platinum
rating—the highest—under the U.S. Green Building Council's Leadership in Energy and
Environmental Design (LEED)™ rating system (Version 1.0). In October 2003, this building was
one of only two certified Platinum in the nation, and it is the only laboratory to achieve this level
of recognition.
The mission of the Donald Bren School is "to play a leading role in researching environmental
issues, identifying and solving environmental problems and training research scientists and •
environmental management professionals." The school trains graduate students in rigorous,
" -rI j Q Silver;
'•-.T"o Certified
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
-------
LABS FOR THE 21 ST CENTURY
interdisciplinary approaches to environmental problem-
solving in a curriculum that blends natural science, social
science, law, and policy. It can accommodate about 100
master's degree students and 50 doctoral students annually.
During the development of construction documents
for the school's new building in the late 1990s, and follow-
ing an endowment from the Donald L. Bren Foundation,
the advisory board decided that it should be a "living lab-
oratory" for the technologies and design approaches that
it advocates. The school then commissioned reviews by
various outside experts and, midway through the design
process, began moving toward being the "greenest" build-
ing on the UCSB campus. The Greening of Bren Hall, a
report issued in October 1999, described how the building
could set an example of what can be achieved .through the
conscientious application of sustainable design principles.
''Architecture holds a mirror before society: Design
Interprets our values, reassesses our priorities, and
reflects them back to us. Sustainable design can embody
ideas about environmental responsibility, inspiring and
educating its t/s@rs."The Greening of Bren Hall. October
1999
Ultimately, Bren Hall was designed to surpass
California Title 24's required standards for energy efficien-
cy by more than 31 %, through its many energy-efficient
features. These include naturally ventilated rooms in the
office wing of the building, premium-efficiency equip-
ment motors, variable-volume pumps, variable-air-
volume (VAV) laboratory exhaust and supply systems,
and daylighting controls. Staff also obtain real-time build-
ing performance data as part of an extensive energy-use
monitoring and management system.
The university's experience with Bren Hall has
prompted it to adopt sustainable design guidelines for all
UCSB projects. These guidelines include mandating the
attainment of a LEED Silver certification and establishing
a campus-wide approach to LEED.
This case study of Bren Hall is one in a series pro-
duced by Laboratories for the 21st Century ("Labs 21"),.
a joint-program of the U.S. Environmental Protection
Agency (EPA) and the U.S. Department of Energy (DOE).
It is geared toward architects and engineers who are famil-
iar with laboratory buildings. This program encourages
the design, construction, and operation of safe, sustain-
able, high-performance laboratories.
Project Description
Donald Bren Hall is a four-story classroom, office, and
laboratory building that houses the Donald Bren School of
Environmental Science & Management at UCSB. Bren Hall
contains three floors of teaching and research laboratories
and four floors of offices. The architect was Zimmer,
Gunsul, Frasca Partnership of Los Angeles, California.
The mechanical and electrical engineer was Flack + Kurtz
Inc. of San Francisco.
The building contains 84,672 gross square feet (ft2)
(46,304 net ff.2) of space (see Table 1). The construction cost
was $22 million ($260/gross ft2), and the total project cost
was $26 million.
The design goal was for Bren Hall to be the best-
performing sustainable building to date—one of the very
best of UCSB's teaching and research buildings—and a
model not just for other UC buildings but for all those
in California. Dennis J. Aigner, Dean of the Bren School,
said, "What we want to do is create a new standard for
construction, not just at UCSB but throughout the whole
university system."
Layout and Design
Bren Hall includes faculty and administrative offices,
research and teaching laboratories, and seminar rooms
for applied and quantitative ecology, earth sciences,
environmental engineering, environmental microbiology
and toxicology, and environmental policy and resource
management programs. An open courtyard unites the lab-
oratory wing and the office wing. Upper-level walkways
provide access to offices as well as spaces for planned and
spontaneous interdepartmental interactions. A floor plan
is shown in Figure 1 and the courtyard in Figure 2.
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-------
LABS FOR THE 21ST CENTURY
Bgure 1. Bren Hali second floor plan
The form of the building serves to mediate between
the campus and its coastal location, taking advantage of
the site's sea air and views. On the eastern side of the
building is a four-story, rectangular laboratory wing with
east-facing exterior terraces on the third and fourth floors.
On the ocean side of the campus, a less formal, "organic"
curve defines the office wing.
A sawtooth pattern along the office wing's facade is
designed to maximize views and provide natural light for
offices. The ground floor of the office wing houses spaces
dedicated to teaching; it includes a lecture hall that can
seat 100 people and several 1,200-ft2 classrooms and
breakout rooms. The first floor also includes "wet" teach-
ing labs with fume hoods for watershed science. Figure 3
shows the interior of a teaching laboratory.
The prefunction space for the rooms is an interior
courtyard that can be accessed via three portals at north,
south, and northeast points of the building. Stairs near
the portals lead to a large, second-level terrace offering
panoramic ocean views. The second floor contains
both "wet" and "dry" labs for teaching environmental
microbiology, chemistry, and geography. It also houses [hi
departmental administrative offices, support facilities, and
a conference room. On the third floor are the computer
science labs. '.
Interior terraces (see Figure 4) at the second and third
levels overlook the courtyard below. The courtyard's open
walkways are lined with a two-story vertical trellis that
will be covered with green vines when they are fully
grown.
Utility Servicing
Utility servicing is provided by a horizontal piping
distribution system. Laboratory piping utility racks are
located in the corridor. Each room has an isolation valve
for each service. Access to each lab's mechanical equip-
ment, ductwork, laboratory waste piping, and ventilation
piping is above the ceiling.
Design Approach
In 1997, the school received a sizable endowment
from the Donald L. Bren Foundation, established by
Donald Bren, a California real estate developer who
strongly supports sustainable design. Although the design
process for a new building had already begun, the school
advisory board decided at that point that a School of
Environmental Science & Management should be a
living laboratory. So, the project moved from simply -
constructing a building in which environmental science
is taught to creating a structure that is itself an example
of environmental sensitivity.
m
i
Figure 2. Bren Hali features an open courtyard between
laboratory and office wings.
-------
LABS FOR THE 21ST CENTURY
Toilets on the first floor also use reclaimed water from
the local utility. None of the urinals contain water, and
each is estimated to save 45,000 gallons of water per year.
AH toilets have automatic flush valves, and low-flow
fixtures are used throughout the building.
i Measurement and Evaluation
Approach
Bren Hall has a metering system to help operate the
building efficiently; the system has an educational func-
tion for students and faculty, as well. Additional metering
monitors the actual loads of dry labs, wet labs, and offices.
For ease of access, Web interface systems also monitor
many of these items. The resulting data are being shared
in "Labs 21" benchmarking efforts to assist others in the
design of new laboratory buildings. The data will also
help the University of California with designs for future
sustainable buildings.
Building Metrics
The data in Table 2 compare design estimates to
building energy performance estimates calculated from '
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-------
LABS FOR THE 21ST CENTURY
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Figure 1. Bren Hall second floor plan
The form of the building serves to mediate between
the campus and its coastal location, taking advantage of
the site's sea air and views. On the eastern side of the
building is a four-story, rectangular laboratory wing with
east-facing exterior terraces on the third and fourth floors.
On the ocean side of the campus, a less formal, "organic"
curve defines the office wing.
A sawtooth pattern along the office wing's facade is
designed to maximize views and provide natural light for
offices. The ground floor of the office wing houses spaces
dedicated to teaching; it includes a lecture hall that can
seat 100 people and several 1,200-ft2 classrooms and
breakout rooms. The first floor also includes "wet" teach-
ing labs with fume hoods for watershed science. Figure 3
shows the interior of a teaching laboratory.
The prefunction space for the rooms is an interior
courtyard that can be accessed via three portals at north,
south, and northeast points of the building. Stairs near
the portals lead to a large, second-level terrace offering
panoramic ocean views. The second floor contains
both "wet" and "dry" labs for teaching environmental
microbiology, chemistry, and geography, It also houses
departmental administrative offices, support facilities, and
a conference room. On the third floor are the computer
science labs. \
Interior terraces (see Figure 4) at the second and third
levels overlook the courtyard below. The courtyard's open
walkways are lined with a two-story vertical trellis that
will be covered with green vines when they are fully
grown.
Utility Servicing
Utility servicing is provided by a horizontal piping
distribution system. Laboratory piping utility racks are
located in the corridor. Each room has an isolation valve
for each service. Access to each lab's mechanical equip-
ment, ductwork, laboratory waste piping, and ventilation
piping is above the ceiling.
Design Approach
In 1997, the school received a sizable endowment
from the Donald L. Bren Foundation, established by
Donald Bren, a California real estate developer who
strongly supports sustainable design. Although the design
process for a new building had already begun, the school
advisory board decided at that point that a School of
Environmental Science & Management should be a
living laboratory. So, the project moved from simply
constructing a building in which environmental science
is taught to creating a structure that is itself an example
of environmental sensitivity.
Figure 2. Bren Hall features an open courtyard between
laboratory and office wings.
-------
LABS FOR THE 21ST CENTURY
Figure 3. Interior ot a teaching laboratory in Bren Hall
UCSB then commissioned the architect to prepare a
feasibility study that would show how the building could
achieve the greatest level of attainability. Many recom-
mendations from the resulting Greening of Bren Hall
report were implemented in the new building, which was
completed in 2002. In addition, Bren Hall is the first UCSB
building to have been fully commissioned by a third party.
In this case, an independent commissioning authority con-
ducted a review of the design and construction documents
at multiple phases throughout the design process.
Technologies Used
Among the sustainable technologies used in Bren Hall
are numerous recycled materials, natural ventilation, day-
lighting, and energy-efficient motors and fans. A solar
electric system has also been installed to generate some
of the building's power.
Recycled Materials
Recycled, sustainable materials were very important
in the design and construction of Bren Hall. The original
site was a parking lot; all the old asphalt and concrete
curbing were ground up and reused as base. Contract
specifications required the builder to separate and reuse
waste and to minimize debris taken from the site.
Desilting facilities were placed at each drainage outlet,
and hay bales and fencing helped to control soil erosion
and sediment. After each rainstorm, silt and debris were
removed and the hay bails were replaced. One hundred
percent of the demolition waste and 93% of the construe-.
tion waste were recycled.
In the structural construction, a 20% fly-ash mix in the
concrete was used in the first two floors, and a 17% mix
was used in upper floors. The building's structural steel is
80% recycled material, and rebar has 80%-100% recycled
content. The pan deck is constructed of 30% recycled
material, and fireproofing is 20% recycled material
containing gypsum, polystyrene, common cellulose,
and recycled newsprint.
Recycled materials are also in carpets, lab casework,
rubber flooring, fabrics, wallboard, tiles, ceiling tiles and
grids, insulation, and furniture. Wood paneling and cork
flooring are from certified sustainable harvests. Bathroom
partitions are made of 90% recycled plastics. And restroom
countertops contain 80% post-consumer recycled rumbled
glass.
Linoleum, a biodegradable product, is one of the main
flooring materials used in the hallways. In addition, a
room on the third floor that houses lockers, a kitchenette,
and vending machines has a 100% recycled rubber floor
made of recycled tires. For every 100 square feet of this
rubber flooring, as many as 7.5 tires are diverted from
landfills. Another room has a cork floor.
Other floor areas are covered with "renewed"
carpet—10-year-old carpet tiles that are "super-cleaned"
and redyed. This carpet is free of polyvinyl chloride (PVC)
and is off-gassed before installation to enhance air quality.
In all, 14 tons of used carpeting were recycled rather than
placed in landfills.
Outside, grids around the bases of trees are made of
100% recycled metals. The fire road around the structure
consists of permeable turf-block with a grass overlay.
The building footprint was carefully designed to pre-
serve the site's landscape and its habitats. Original trees
were protected throughout the project, and native trees
were added to provide shade at the west facade. Small
plants on the old site were ground up and reused as mulch
on campus. All native soil from the site was retained and
reused.
Natural Ventilation, Daylighting, and
Lighting
Because it faces the ocean, the office wing needs no
air-conditioning. It relies instead on flow-through ventila-
tion, using operable windows and transoms. Windows in
the office wing have a mechanical interlock (a small sensor
in the frame); when the windows are opened, hot water
convectors (radiators) automatically turn off.
Daylighting is featured in the offices. Photosensor
controls detect the amount of natural lighting in a room
and dim the artificial lighting accordingly. The offices also
have on/off light switches for the electric lighting, which
incorporates energy-efficient fixtures and bulbs and
motion controls.
-------
LABS FOR THE 21ST CENTURY
Energy Efficiency
Bren Hall surpasses California's Title 24 requirements
for energy efficiency by more than the estimated 31 %.
A computer simulation estimated annual energy use at
144,700 British thermal units (Btu) per square foot per year
(144.7 kBtu/ft2/yr). Data based on actual measurements
collected in 2003 from the building's energy monitoring
system (Table 2) show that the building is using signifi-
cantly less energy than the estimate—106.7 kBtu/gross
ftVyr for electricity and gas combined.
These are the building's primary energy efficiency
and renewable energy features:
• Naturally ventilated offices
• Premium-efficiency motors on all equipment
• Variable-volume pumping systems
* Variable-air-volume laboratory exhaust and supply
system
* Daylighting controls
• Maximized chiller and cooling tower efficiencies
• A47-kilowatt (kW) photovoltaic (solar electric) system
There are 17 VAV fume hoods in the building.
Measured data show that the labs use approximately 8
air changes per hour (ACH) when occupied, and about
4 or 5 ACH when unoccupied, such as at night and on
weekends. (See page 7 for more details.)
The three exhaust stacks on the roof are each a differ-
ent size. Each one has a different-sized fan: one for 16,000
cubic feet of air per minute (cfm), one for 23,000 cfm, and
another for 30,000 cfm. The system design and controls
ensure that only one of these fans or a combination of
them is running at any given time, as required to maintain
a minimum static pressure in the exhaust control loop.
If the static pressure can't be maintained, then the next
larger fan or combination of fans turns on as the fan that
was previously running turns off. The exhaust fans use
variable-frequency drives and a bypass damper to main-
tain the proper exhaust stack discharge velocity. Bren Hall
received a LEED innovation credit for the design of this
exhaust system.
The building is connected to a new, multi-building
chilled water loop to provide cost-effective cooling for the
laboratory wing. This loop connects Bren Hall's chiller to
all other chiller plants on campus, so the loop is operated
as if it were one large campus chiller plant. Bren Hall's
chiller, which has a run time of about 15%, can thus take
on a portion of the total campus load as needed. This
allows other chillers to be fully loaded (and operating
most efficiently) before bringing in the Bren Hall chiller.
Because of UCSB's "virtual central plant" control
strategy, the Bren Hall chiller is sized at 300 tons—or
about 25% larger than the building requires. The building
has its own cooling tower. And to reduce the "heat island"
effect, an Energy Star®-rated "white cap" roofing material
reflects sunlight and helps to keep the building cool.
Bren Hall's 47-kW photovoltaic system was designed
to meet about 7%-10% of the building's total electricity
needs. In addition, 31 % of Bren Hall's electricity is
supplied by another renewable power source—methane
landfill gas—through a contract with a "green power"
provider that runs through 2004.
Indoor Environmental Quality
Products such as paint and carpeting had to meet
stringent criteria for low amounts of volatile organic
compounds, or VOCs. There are no asbestos or mineral
fibers in the materials, and no hydro-fiuorocarbons,
hydro-chloro-fluorocarbons, or chloro-fluorocarbons
(CFCs) were used. All paints, adhesives, and finishes
exceed the new South Coast Air Management Air Quality
Standards for 2005.
When the building was completed, all the mechanical
systems were run for two weeks at full capacity. Then all
the filters were changed before occupancy, which greatly
improved indoor air quality. A carbon dioxide monitoring
system also ensures fresh air in assembly spaces.
Water Efficiency
Reclaimed water is piped from the local water utility
to meet 100% of the site's landscape irrigation needs. The
landscaping also features drought-tolerant native plants.
Figure 4. Both interior and exterior terraces overlook Bren Hail's
courtyard.
-------
LABS FOR THE 21ST CENTURY
Toilets on the first floor also use reclaimed water from
the local utility. None of the urinals contain water, and
each is estimated to save 45,000 gallons of water per year.
M All toilets have automatic flush valves, and low-flow
L! fixtures are used throughout the building.
• ':*
Measurement and Evaluation
Approach
Bren Hall has a metering system to help operate the
building efficiently; the system has an educational func-
tion for students and faculty, as well. Additional metering
monitors the actual loads of dry labs, wet labs, and offices.
For ease of access, Web interface systems also monitor
many of these items. The resulting data are being shared
in "Labs 21" benchmarking efforts to assist others in the
design of new laboratory buildings. The data will also
help the University of California with designs for future
sustainable buildings.
Building Metrics
The data in Table 2 compare design estimates to
building energy performance estimates calculated from
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-------
LABS FOR THE 21ST CENTURY
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>ortionaUy.;This signal p'romptsjtne "fume'nood'mririift":
\ ^r^S^^^^^^^^^\'.^^^n^^^^T^A'^f^--f
I- ex%ustya|ye,;n™in|nrar^ £ Jf ill
5 velocity at each'Kbbd Wnsriir^
I cfm flow at the valve) to the rna&up air cipn^rp|nel:;:fe=:; >
r The make-up air controller card_caiwiafettptaffiiime .':t
j hood exhaust volume by summing &e feedj&kck signals 3*2-
f from the hood exhaust valvesi'a^grai^atingi^-^yl.hopid^;
j exhaust sighalLT he make-upaircon^Uerlcard^mES'ir^-^
j a constant, adjustable.net negatiyejqffsXbe^em itlve rai^>, i
i' trol zone's totarexhaust .and the makerup^yohtmesi;/:' ;i;3
j This .offset shouldriot vary with changes in tHe:yblume \ j. i<
'< of the exhaust "•.' ':i.. '-I v''!'j-''; •';• }•;.•.,.*' •''^^iCSB'-l"-;^''";
! 'To maintain a negative room JolffoS/.tHemajfeujpiair'^" :•.'
i controller card resets the total ^---" ~- i---"--^^-5-"^''':.?! . >
] tracting the,quantity of offset desiredl'.The, result'isja'.t'dtaf '!.
I fume hood make-up air signal; j.t represents^ thelyplume ,s: vj:
of supply air needed,to. satisfy fume Hood demanp-with|;- •!•';:
5 respect to tKe':desir^.constotoffsetf ?*? ''7!*^:/:^> .%t^":'
i _ The make-up air contrblier card mkintainsfa^ni-; J J. ;g
| mum volume of iyentUatipn make-up'aif.to'th^ labprato'ry,;,';j:
j.because supply airitb; the spacie j-^---1-1 ---^rlii*:'*,•??•-¥?¥* •-• •
. volume:The make-up air,,command;sHgnalisjgenlfaled'';/ v.
\ when the system compajres ttite niinimumy|rtHiation^r:|i'':-'
; signal to the totarhood-makerup'airiignaVantfseiectsf ji-V;"':;
I the higher of these two signals as'meomrunanidS:;:^!:1';' \%^,'
'• When the|mihimum:yolume of yentiiation make^upt?..
j 'air is being delivered to a robm,'_andrtiie-fumbJbcitj.? |:jt-!;:fe -:
j exhaust valve is'exhaustihg less than this minimumypl-'ij ,^"
i -ume, the make-up^air;cbntroller UKreases^he'ciaiSi^aliidic ? ii;
I signal to theBroom's; general exhaust•'yalye;|rhis;yalve -WvF •"
, n~*~, , ™.«i.. t_ iv_• t..-^.~ i-__ j. -_,-•_-,. _. •_.-, '."•••'-•••j;ne.y
: hood s sash isslpwer; than it shpuldbe;for the make-uprair.:;;":
i- valves' minimum volume of yentilation^ rj!' ^ |.!C:vS'S-!"H
| "When a control zone occupancy sehspHndicateSt&!i^
j the zone is unoccupied, the energy mahagement=cbhtTol; I *
the sensor fails, the control zone minimum ventilationiair
volume is reset to the scheduled value for an.occupied :•':;
I _. On^a call for cooling, the'EMCS sends;a\igna|tp'the i:sf
1 ^^?"uf air controi panel. This signal resets.ttite minimiam j
\ ventilation signal from the scheduled suppl£flbw minir, C/'!
j mum to the scheduled flow'maximum. : •' { ;i:> 7 '•?.p^:":; 1
measured data collected in 2003. Data measurements
taken for a shorter period of time were extrapolated for a
full year, because the building was just completing its first
year of operation.
The table shows that measured energy use for ventila-
tion is lower than estimated. The estimate did not assume
that all the exhaust and supply fans would be operating
together. As noted earlier, the exhaust fans operate in
stages, based on need. The design estimate assumes
2.2 cfm/net ft2 for ventilation in the labs. Measured data
show only about 1 cfm/net ft2. The cause of this discrep-
ancy could be that some planned lab equipment has not
yet been installed, as well as that the innovative exhaust
control strategy is working as designed. Because this
mixed-use building has both classrooms and labs and not
many fume hoods, ventilation loads will be lower than
those of many other buildings in the Labs 21 benchmark-
ing database.
Table 2 also shows a discrepancy between design
estimates and measured data for plug loads. One reason
is that Bren Hall plans to purchase and install significantly
more new lab equipment. Given the measured data for
plug loads, and assuming 1.8 W/ft2 of plug loads in all
spaces but labs (and other assumptions listed in Table 2,
footnote 6) actual plug loads in labs are probably about
2.2W/ft2.
The design estimates in Table 2 indicate that the
building would use 197 kBtu/ft2/yr for electricity only.
This estimate is high because it doesn't account for usage
schedules. The Bren Hall energy simulation predicted
energy use in the "as-designed building" at 144 kBtu/ft*/yr
for electricity and gas. Based on this simulation, the build-
ing was estimated to be 31 % more energy efficient than
the Title 24 base case at 209 kBtu/ft2/year. The measured
performance is almost 50% better than this simulated
base case. Measured performance is 107 kBtu/ft2/yr,
however, or 25% better than predicted for this building
in the simulation.
Summary
Bren Hall at UCSB's Donald Bren School of
Environmental Science & Management is one of two
LEED-certified Platinum buildings, and the only laborato-
ry building to achieve this recognition. Once the decision
was made to make this a high-performing, sustainable lab
and classroom building, this goal was embraced by the
school's leadership and accomplished. Its design incorpo-
rates many energy-efficient and sustainable features,
making it a living laboratory for students and faculty.
Its Web site carries this a step further by sharing informa-
tion about greening product suppliers and the cost of
-------
8
various measures (seewww.bren.ucsb.edu/about/
greening_information.html).
The building also includes a comprehensive real-time
energy-use monitoring system. This system aids in
managing the building's energy use and helps to identify
more opportunities to save energy at the University of
California and elsewhere. Bren Hall thus represents a
great resource for teaching the next generation of policy
and environmental management professionals and
research scientists.
Acknowledgements
This case study would not have been possible without
the contributions of Jim Dewey and Perrin Pellegrin at
Donald Bren Hall; Stacey Williams of Zimmer, Gunsul,
Frasca partnership; Todd See and Stephen Scaife of
Flack + Kurtz; and Lisa Fay Matthiessen of Davis Langdon
Adamson. This study was written by Nancy Carlisle of the
National Renewable Energy Laboratory with the assis-
tance of Otto Van Geet, P.E., Paula Pitchford, editor, and
Susan Sczepanski, graphic artist, all of NREL.
For More Information
On Donald Bren Hall:
Jim Dewey
Physical Facilities
University of California, Santa Barbara
Santa Barbara, CA 93106
Phone: 805-893-2661 xllOl
E-mail: jim.dewey@pf.ucsb.edu
On Laboratories for the 21st Century:
Daniel Anton
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W.
Washington, DC 20460
202-564-7509
amon.dan@epamail.epa.gov
Will Lintner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-4858
william.lintner@ee.doe.gov
Nancy Carlisle, A.I.A.
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384-7509
nancy_carlisle@nrel.gov
Laboratories for the 21st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.epa.gov/labs21century/
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
www.eere.energy.gov/femp
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
DOE/GO-102004-1794
February 2004
Printed with a renewable-source Ink on paper containing at least
50% wastepaper, including 20% postconsumer waste
-------
!"~ -•—!- !-r— •.
.,<; ,•:••'>:-:,
LABORATORIES FOR THE 21ST CENTURY
CASE STUDIES
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Case Study Index
Laboratory Type
Construction Type
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'
Itf Cohtrpfe
d MARIAN E. KOSHLAND INTEGRATED
NATURAL SCIENCE CENTER AT HAVERFORD
COLLEGE, HAVERFORD, PENNSYLVANIA
Waterconservation : ,;.. ;' ;
Rwiewables?.. v:!' .'.
Introduction
The Marian E. Koshland Integrated Natural Science Center (KINSC) reflects the commitment of
Haverford College's faculty and administrators to providing a productive, flexible, and motivating
!Q (Selling concepts to j learning environment. When the evolving space requirements of the institution's natural sciences
• -.;: stakeholders / j, •.. { departments began to exceed those of the existing facilities, the faculty and administrators started
;« Design process ,,--! / .;, _; to investigate the benefits of co-locating all the college's natural sciences activities. They recognized
i;Q: Platinum • ' ':- ,;:' - -i
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United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
-------
LABS FOR THE 21ST CENTURY
;I.| that most science graduates' careers will
require knowledge in disciplines other than
their degree areas, and that participating in a
ij wide range of scientific experiences is in the
jSJ students' best interests. The planners wished
^| to create an environment that provides state-
of-the-art research facilities and promotes
interactions within the laboratory as well as
among degree disciplines. As a result, the
185,423-ft2 (gross) KINSC was designed and
constructed. This distinctive academic center
includes laboratory, classroom, office, and
supporting spaces to house all of the Haverford
College natural science departments.
The KINSCs unique mechanical system
conditions the facility's makeup air separately
from the air that maintains thermal comfort.
Energy wheels precondition the makeup air to
»•••**••••
"The response to the new KINSC has been outstanding. •
The people who use the building love it. " Norman Bicker,
client (former Director of Physical Plant), Haverford College,
Haverford, Pennsylvania
space-neutral conditions (the temperature and relative
humidity levels desired for comfort within the building).
Individual fan-coil units located within each space or
building zone further condition a portion of this makeup
air to maintain desired thermal conditions in each space.
There is no need for reheat because the air entering the
fan-coil units is at space-neutral conditions. Because the
conditioned makeup air is distributed through a network
of plenums, there is very little ductwork in the building.
Designers estimated that the KINSC system saves 52% in
cooling and heating energy annually for the entire facility
as compared to a system using 100% outside air, variable
air volume (VAV) fume hoods, and no energy recovery.
When compared to a similar conventional laboratory
system that incorporates sensible energy recovery, the
comparable thermal energy savings are still 45%.
This study is one in a series produced by Laboratories
for the 21st Century ("Labs 21"), a joint program of the
U.S. Environmental Protection Agency (EPA) and the
U.S. Department of Energy (DOE). The program is geared
toward architects and engineers who are familiar with
laboratory buildings, and encourages the design, construc-
tion, and operation of safe, sustainable, high-performance
laboratories.
• lib SUb Suppon
j~3Cta$jroora
JS Office
Figure 1. KINSC first-floor plan
Project Description
The KINSC in Haverford is a four-story, 185,423-
gross-ft2 laboratory and classroom building. It houses
facilities for both undergraduate- and graduate-level
research activities for seven natural sciences departments
(biology, chemistry, physics, mathematics, computer sci-
ence, and psychology). As a fully integrated, cooperative
educational facility, it also contains faculty offices,
communal/interactive areas, and a natural sciences
library. The building construction was completed in two
phases in 2001 and 2003 at a total project cost of $42.6 mil-
lion ($230/gross ft2). Ayers/Saint/Gross (ASG) Architects
and Planners of Baltimore, Maryland, and CUH2A of
Princeton, New Jersey, provided the architectural and
engineering design services, respectively. Earl Walls
Associates of San Diego, California, was the laboratory
planner, and the general contractor/construction
manager was Skanska U.S.A. Building, Inc. of Blue Bell,
Pennsylvania (formerly Barclay White, Inc.).
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LABS FOR THE 21ST CENTURY
BlfeiaMowWi
i-:o:;f:::.:;:;!':i;«l^iittS;i;tS;^e:;|;|i;-3i->;
. • • ..i.. ••^.'•.••.•'*.~.'.;j~,'.',:'.'.°Jlr':^y;'.*£**4 »•;.,
e;;noted)tl h
...4; J.i:Jt,-joX,Jj.^S3^,'..-; • i yt • ',y_:
Communal/Interactive spaces;§
^ff, ..si-WivjaMA ut%*»<>(--''-«::*-5i- Sv<-- c" fvt.y>**t'
torgr^uareleetjV^i^
^^lns^i|^eK;iij|i|!ipg
Figure 2. The bowtie configuration of the benches in the biology
laboratories facilitates interactions among students.
Layout and Design
The KINSC joins the southern ends of the existing
Sharpless Hall and Hilles Hall. A section of the building,
known as the "Link," ties together these existing buildings
and the newly constructed KINSC. Figure 1 shows the
KINSC first-floor plan, and Table 1 gives a breakdown of
space by function.
Laboratory Design
The laboratory designer worked closely with the
Steering Committee, which consisted of Haverford
College faculty and staff, to optimize the laboratory
configuration and bench design to facilitate teaching.
Mock-up benches were constructed during the design
phase so that the Steering Committee members could test
their bench design recommendations. The "bowtie" bench
design for the biology laboratories was a result of this pro-
cess (Figure 2). The opea double hexagonal bench design,
which encourages interaction between groups ranging
from 2 to 8 students, also gives a clear line of sight across
the bench, further promoting conversation between
groups.
The chemistry laboratory has the more conventional
straight benches because chemistry students typically work
on their own, instead of in the groups usually found in
biology laboratories. Double-sided fume hoods used in the
larger chemistry laboratories furnish a dear line of sight
between the professors and the students (Figure 3).
Every teaching laboratory has Americans with
Disabilities Act (ADA) accessible workstations.
Figure 3. Double-sided fume hoods provide a clear line of sight to
all student workstations in the chemistry laboratories,
Utility Servicing
Four vertical interior shafts in each of the building's
east and west wings are the conduits through which the
utilities are run. These shafts also serve as the plenums
through which space makeup air is delivered. Pipes and
other utilities run horizontally from these shafts via a uni-
strut-type rack system mounted to the ceiling. Utilities are
in a standard stacked configuration with the air distribution
on top, piping in the center, and data and electrical conduits
on the bottom to give an organized appearance in the
spaces without finished ceilings. Makeup air is distributed
through corridor ceiling plenums as well as the vertical
interior shafts. Data cable trays and lighting electrical con-
duits are also routed through the corridor. Exhaust air is
ducted through separate exterior vertical shafts.
-------
LABS FOR THE 21ST CENTURY
, The vertical shafts and plenum distribution design
strategy maximizes the ceiling height. The floor-to-floor
height for most parts of this building is 13.5 ft, but ceiling
I heights range from 10.5 ft to 15 ft (these vary according to
| floor and wing). Only the corridors have ceilings installed
j below the maximum floor-to-floor height to accommodate
the horizontal makeup air plenums. All piping, ductwork,
and other utilities outside the corridors are exposed to
maintain the feeling of tall ceilings.
Mechanical rooms are located in the enclosed pent-
house on the fifth floor of the east wing and in the base-
ment of the west wing of the newly constructed portions
of the KINSC An existing mechanical room in the
Sharpless Hall basement remains in use.
The building receives steam service from the campus
central plant, where most of it is converted to hot water.
The remainder provides humidification. Two dedicated
240-ton chillers supply chilled water to the building.
There are 386 gross square feet of building area per ton of
chiller capacity in this building, which is very similar to
common office building capacity requirements. Haverford
College turns off the chillers and drains and shuts down
the cooling towers during the winter months to conserve
energy.
Communal Spaces
Communal spaces are liberally located throughout the
building to serve as comfortable and convenient areas
where students and faculty can congregate. Each commu-
nal space contains comfortable seating and a white board
or chalkboard. These spaces are designed to foster an envi-
ronment that encourages communication among the stu-
dents and faculty of the various scientific disdplines
housed within the building.
Design Approach
Consensus building was the foundation of the KINSC
design process. The ASG-ied design team and the KINSC
Steering Committee met regularly throughout the project
design phase. A variety of tools were employed to help
meeting participants fully understand the meaning and
impact of an "interdisciplinary" education. The design
team tested proposed building design solutions with
larger campus-wide issues of scale, massing, campus cir-
culation, and building orientation. Three-dimensional
"blocking and stacking" models, flow diagrams, and
bubble diagrams allowed design team and committee
members to visualize space interactions and conceptualize
building massing.
The design team and the committee established up
front that minimizing building operating costs was a pri-
mary project goal. Minimizing these costs is directly tied
to energy efficiency, especially in a laboratory building.
Because conditioning laboratory ventilation air is a princi-
pal source of energy consumption, KINSC designers
decided to use energy recovery systems, which require co-
locating the supply and exhaust air streams, early in the
design process. This necessitated coordination between
the architectural and engineering designs throughout the
design phase.
During the early design phase, the planners also con-
sidered the fume hood locations, recognizing how the
fume hoods interacted with other mechanical system com-
ponents and adjusting the building design to optimize
overall mechanical system performance. For example, the
organic and general chemistry laboratories, the most-used
laboratory spaces in the building, are located on the top
floor of the east wing. Locating these laboratories just
under the KINSC mechanical room shortened the fume
hood exhaust system, which accommodates the large
number of fume hoods that these laboratories require as
efficiently as possible at the lowest cost. '
Technologies Used
Site Related
The building project adheres to sustainable design
practices that minimize disturbances and impacts to the
site and regional environments. The new facility is con-
structed on a previously disturbed site and the building
is physically attached to two existing historic buildings
(Sharpless Hall and Hilles Hall). To make room for the
KINSC on the site, two additional buildings were moved '
a short distance instead of being destroyed.
Heating, Ventilating, and Air-Conditioning
(HVAC)
The most groundbreaking energy efficiency design
feature of the KINSC is the strategy used for laboratory
ventilation and space conditioning. A series of energy
wheels condition the exhaust and makeup air to create
space-neutral air. Individual fan-coil units (FCUs) located
within each space or building zone further condition a
portion of this makeup air to maintain desired thermal
conditions in each space. Reheat is not needed because the
air entering the FCUs is at space-neutral conditions. The
conditioned makeup air is distributed through a network
of plenums. Distributing the air through plenums mini-
mizes the need for ductwork and minimizes air pressure
drops. Designers estimate that the strategy consumes 52%
less energy than an air-handling unit system that uses
100% outside air.
The KINSC system avoids the need to both cool and
heat all the air delivered to the laboratories. A total energy
-------
I
LABS FORTHE 21ST CENTURY
72°F/26.4 Btu/lb
Exhaust
15,887 Ib/h
67°F
24.9
Btu/lb
J2
Q = 58.8
MBtu/h
57°F/22.7 8Mb
52°F
21.2
BMb
1
|cj
67.5°F
28.2
Btu/lb
fl
tj
67.5°F
28.2
Btu/lb
Q = 111
MBtu/h
Q = 0
0 = 208
MBtu/h
82.5°F
35.8 Btu/lb
15,887 Ib/h
93°F/41. 3 Btu/lb
Figure 4. KINSC laboratory makeup air and comfort conditioning
system. Values shown in this figure are based on the following
assumptions: laboratory area of 650 ft2; four VAV fume hoods, each
operating at an open 900 cfm exhaust; four people working in the
space, operating internal lighting and equipment load of 5 W/ft2;
and a summer envelope cooling load of 2400 Btu/h.
wheel and a sensible energy wheel work in series with
heating and cooling coils to condition all incoming
outside air to space-neutral conditions. Figure 4 illustrates
how the energy wheels are integrated into the makeup
air-conditioning system. Designers specified a special 3-A
molecular sieve desiccant to ensure minimal cross con-
tamination between the exhausted laboratory air and the
air delivered to the spaces.
The space-neutral conditioned makeup air is distrib-
uted through a building plenum delivery system, which
consists of vertical shafts that are open to the corridor ceil-
ing plenums on all floors. The fume hoods and general
building exhaust system passively draw the air from the
corridor plenums and deliver it into the laboratories. The
air travels through back-draft dampers that are made of
fabric and installed in the wall partition between the lab
and the corridor. These self-adjusting dampers maintain
a negative pressure of approximately 0.03 in. in the
laboratory, compared to the corridor. When a laboratory
door is open, the back-draft damper instantly shuts,
ensuring inward airflow through the door for improved
containment.
A simple control scheme combined with the back-
draft damper maintains the desired laboratory differential
pressures. This design avoids the need for a VAV box,
differential air pressure controls, and a reheat coil on the
supply air ductwork. The design results in
a first cost savings and a low supply air
pressure drop, which saves on fan energy.
Fan coil units in each laboratory sensi-
bly condition only the quantity of air needed
to maintain comfortable space conditions.
Thermostats in each laboratory control the
FCUs and the FCUs operate only during
occupied hours. Each FCU serves just one
laboratory to avoid cross contamination of
fumes among the laboratories.
The KINSC laboratory HVAC system
design has many advantages beyond
heating and cooling energy savings:
• Ductwork is minimized. Fume hoods and
general building exhaust system passive-
ly draw the makeup air from the plenums
and into the laboratories. The only supply
air ductwork that is needed introduces the space-neu-
tral air into the plenums and then delivers the supply
air from the FCUs in each space. Ductwork is also used
to direct the fume hoods' exhaust air into the laboratory
exhaust air system.
• No condensation is present in the FCUs. The FCUs
provide only sensible conditioning because the energy
wheels previously accomplished all of the required
dehumidification. Avoiding condensation in the FCUs
eliminates the need to install a system to remove con-
densate, along with the possibility of fan coil equip-
ment deterioration problems resulting from moisture
buildup.
• Control, balancing, and startup are simpler. A standard
flow tracking control located at one location within the
makeup air unit synchronizes the makeup supply air
quantity with the quantity of air exhausted from the
spaces and maintains constant global building pressure
conditions. Balancing and startup consists of properly
setting the makeup airflow tracking controls and cali-
brating the fume hood exhaust controls.
• Fewer control points and the passive makeup air deliv-
ery system combine to simplify the operations and
maintenance requirements.
• The system operation is extremely quiet. Because the
large quantities of makeup air are delivered through
plenums, the system is virtually silent when operat-
ing. The silent operation facilitates instruction in the
laboratories and classrooms and enhances the learning
environment. \
-------
6
IABS FOR THE 21ST CENTURY
One drawback of the KINSC HVAC system has been
maintenance costs for the high number of FCUs, particu-
larly the costs of filter change outs. This added mainte-
nance cost is acceptable, however, when compared with
the benefits of lower construction costs, quieter laborato-
ries, and more efficient energy use.
An outside air inlet bypass damper on the suction side
of the constant volume exhaust air fans maintains constant
stack velocity. Most of the 110 fume hoods in the building
are VAV fume hoods (a few constant volume hoods are
located in the west wing). All the teaching laboratories are
designed so that one fume hood can remain active when all
the other fume hoods in the laboratory are shut down. This
strategy was intended to allow for the continuous operation
of only one fume hood per laboratory, to meet the mini-
mum ventilation rate for the laboratory, except for the time
periods when students are occupying the laboratories.
Of the considered strategies, the mechanical system
design selected for the KINSC was the strategy that had
both the lowest first cost and operating costs. The cost of
the energy recovery devices in the makeup air-conditioning
system nearly doubled the first cost of this equipment,
compared to a conventional 100% outside air system. But
the increased cost for the energy recovery devices was
more than offset by savings resulting from a reduced
heating and cooling plant size, the reduced supply-air
ductwork, and a simpler control system. These savings
reduced the mechanical system construction cost to 10%
less than that of comparable facilities built in the region.
Lighting
Suspended, bidirectional fixtures with T-8 fluorescent
lamps light the laboratories, classrooms, communal
spaces, and corridors. In the laboratories and classrooms,
the fixtures are set to supply 85% of the lighting as down
lighting and 15% as up lighting, for an 81% fixture effi-
ciency. The fixtures in the communal spaces and corridors
are adjusted to provide a 50%-50% distribution of up-to-
down lighting, for a fixture efficiency of 94%. Suspended
linear fluorescent indirect lighting fixtures with perforated
bottoms (97% up and 3% down) illuminate the offices.
Fluorescent task lighting is installed in the offices with
overhead storage as well as in the library study carrels.
Compact fluorescent down lights are used in the circula-
tion areas, offices, and library.
Manual switches control the lighting in the laborato-
ries and classrooms and are wired to permit separate
switching of rows of lights. A relay-based lighting control
system is used in the circulation areas. This system
incorporates time-of-day scheduling, override switches,
and/or photocells (outdoor and entry lobby lighting).
Wall-mounted occupancy sensors with switch overrides
control the office lighting.
Indoor Environmental Quality (IEQ)
The KINSC design delivers good IEQ through the
following features:
• The connection with the outdoors is an important
design feature of the KINSC. Almost all classrooms,
offices, and communal/interactive areas have oper-
able windows, and all stairwells have operable win-
dows and skylights. Students and faculty report that
the availability of daylighting and the views to the
outdoors from virtually all regularly used spaces in
the building make for more comfortable learning and
working environments.
• The mechanical system design results in a relatively
small amount of air traveling through the FCUs. Less
air means less noise.
• No condensation at the FCUs eliminates the possibility
of indoor air quality problems associated with the
accumulation of condensate in occupied spaces.
• Whenever possible, materials and finishes that emit
low levels of volatile organic compounds (VOCs) were
used to minimize the introduction of indoor pollutants.
• The simple control strategy of the mechanical and
electrical systems in the building ensures that the
occupants are comfortable in the spaces.
Materials
Locally quarried stone was used as a building facade
material, and regionally quarried slate is used extensively
within the building. The precast concrete structural fram-
ing was manufactured locally. The concrete masonry'units
(CMU) and most of the ground-faced block was also local-
ly manufactured. Finally, all slate blackboards and some
of the furniture found in the building were reused from
other spaces on the Haverford College campus.
Building Metrics
Table 2 summarizes the building's metrics and pro-
vides the estimated energy use calculated using the key
design parameters. Because the KINSC is not metered sep-
arately from other buildings on the Haverford College
campus, energy use figures, as reported by measured data
or energy utility bills, are not available. The energy con-
sumption of the ventilation system is low compared to
other buildings featured in the Labs 21 case study series
because of the low fan power requirements. Distributing
the air through a network of plenums minimizes the need
for ductwork, which significantly reduces system static
-------
LABS FOR THE 21 ST CENTURY
^Annual Eneray:usage;!sssi£!!=ii:;P:!:X, i?,:'
*nnMB»w«yUse
S:\tendlaapri |i^.l-T:';:""5;;^i|;
"''
(sum of wattage of all thel
supplyjahcl the e&aulj. 1:' !•
.fansV?!y" vS^fflfivS;
pressure. Less fan power is then needed to distribute the
air. The calculated energy use is 22.2 kWh/gross ft2/yr.
Summary
The strong rapport between the design team and
Steering Committee was a key factor in the success of the
KINSC project. The building design evolved through an
iterative process consisting of continuous communication
The project construction cost was less than originally
anticipated, primarily because distributing makeup air
through plenums minimized the amount of ductwork in
the building. In addition, the energy recovery system
reduced the amount of heating and mechanical cooling
needed to meet building loads, which resulted in
decreased heating and chiller capacity requirements.
Designers chose not to install ceiling finishes in most of the
between the design team and the Steering Committee. The building as a strategy to give the building a taller, more
design schedule set at the beginning of the project was not
adversely affected by the extensively iterative nature of
the design phase. The final design balanced the program
interdisciplinary requirements, quality of construction
and finishes, and budget (final project cost of $230/ft2).
Finally, the design team and Steering Committee felt that
they successfully created a building that assimilates well
into the Haverford campus and constructed a facility that
can be used and enjoyed by all, not just the scientists it
houses.
open feeling, and for additional cost savings.
Other innovative features of the KINSC include locat-
ing fume-hood-intensive laboratories on the top floor just
under the mechanical room (to accommodate the large
number of fume hoods as efficiently as possible), installing
FCUs so that each unit serves only one laboratory (to
avoid cross contamination between laboratories), and the
practice of turning the chillers off and draining and shut-
ting down the cooling towers during the winter months.
-------
8
LABS FOR THE 21ST CENTURY
Acknowledgments
This case study would not have been possible without
the contributions of Norman Ricker of Haverford College;
Jim Patz and Earl Purdue of Ayers/Saint/Gross Architects;
and Philip Bartholomew of CUH2A. Sheila J. Hayter, P.E.,
of the National Renewable Energy Laboratory (NREL)
authored this case study. Also from NREL, Nancy Carlisle,
A.I.A., and Otto Van Geet, P.E., contributed helpful
comments and peer reviews. Ren6 Howard and Susan
Sczepanski provided editing and graphic design.
For More Information
On the Marian E. Koshland Integrated Natural
Science Center:
Client
Norman Ricker
Haverford College
370 Lancaster Avenue
Haverford, PA 19041-1392
610-896-1100
nricker@haverford.edu
Architect
Adam Gross, F.A.I.A.
James M. Patz, A.I.A.
Earl Purdue, A.I.A.
Ayers/Saint/Gross Architects
1040 Hull Street, Suite 100
Baltimore, MD 21230
410-347-8500
jpatz@asg-architects.com
epurdue@asg-architects.com
Engineer
Philip Bartholomew, P.E.
CUH2A
CN-5380
Princeton, NJ 08543-5380
609-844-1212
pbartholomew@cuh2a.com
On Laboratories for the 21st Century:
Dan Amon, P.E.
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W. (3204R)
Washington, DC 20460
202-564-7509
amon.dan@epa.gov
Will Lintner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120
william.lintner@ee.doe.gov
Sheila Hayter, P.E.
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384-7519
sheila_hayter@nrel.gov
Laboratories for the 21st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.labs21 century.gov
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous future where energy is dean,
abundant, reliable, and affordable
www.eere.energy.gov
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
DOE/GO-102005-2105
June 2005
Printed with a renewable-source Ink on paper containing at least
50% wastepaper, Including 20% postconsumer waste
-------
'""'[; '"" V"
LABORATORIES FOR THE 21ST CENTURY
CASE STUDIES
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' . '• --••,-- - certification process for energy-efficient buildings, is a not-for-profit plant biotechnology and life
Q D'vers tu facto^ '• sciences incubator in St. Louis, Missouri, sponsored by the Monsanto Company. It provides support
,II| Q Carbon trading r ' *' '! services, technical and business advice, and reasonably priced office and laboratory facilities to
«f l! Q Selling concepts to -' • J local start-up companies that commercialize promising new ideas. The center also helps to draw
;;||;j : Stakeholders/;.:,, ' ,. researchers and entrepreneurs to the region and to retain others, such as those who attend local
y&>| 'B* Design projiess . ,' •=•;,... universities and work at the Danforth Plant Science Center, Monsanto, and other nearby firms.
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-------
LABS FOR THE 21ST CENTURY
TKe Nidus Center has many sustainable, high-
performance features. They include a flexible layout,
self-sustaining landscaping, extensive use of daylighting,
an efficient mechanical system with energy recovery, and
| water conservation. Local materials were used extensively,
as well as materials containing low amounts of volatile
organic compounds (VOCs) and those with a high
recycled content.
For all its sustainable feaures, the Nidus Center
received a silver rating through the U.S. Green Buildings
Council (USGBC) Leadership in Energy and Environ-
mental Design (LEED) certification system, Version 1.0.
The facility was involved in pilot projects testing the certi-
fication process and was one of the first 12 buildings to
receive LEED certification. It was the first LEED-certified
lab.
This case study is one in a series produced by
Laboratories for the 21st Century, a joint program of the
U.S. Environmental Protection Agency (EPA) and the
U.S. Department of Energy (DOE). It is geared toward
architects and engineers who are familiar with laboratory
buildings. The program encourages the design, construc-
tion, and operation of safe, sustainable, high-performance
laboratories.
Project Description
The Nidus Center is a two-story, 41,233 gross ft2
(22,554 net ft2) laboratory and office building on the
northeast corner of Monsanto's 210-acre corporate campus
in St. Louis. It was completed in the fall of 1999 at a cost
of $10.2 million for the building, interiors, and site work
($247/gross ft2). It was designed by the architectural firm
of Hellmuth, Obata + Kassabaum, Inc. (HOK). The Struc-
tural and civil engineers were EDM, Inc.; William Tao &
Associates were the mechanical, electrical, and plumbing
engineers. The general contractor was the Park
Corporation.
The center serves entrepreneurial clients who are
. researching, refining, and preparing plant and life science
technologies for the marketplace. The facility offers wet
and dry lab space as well as office space for approximately
8 to 10 companies. It is designed to accommodate
24 wet/dry laboratories and 22 private offices. It also
includes conference rooms, a work room for support
services, and a large break area that adjoins a plant-filled
atrium. The Nidus Center offers important services for
start-up companies, such as business planning and
negotiation assistance, mentoring, and access to sources
of venture capital. A network of professionals is also
available to serve as advisory board members or tempo-
rary management.
Layout and Design
The Nidus Center building is oriented along an east-
west axis; the long sides face north and south to take
advantage of natural lighting. A central hall runs along the
spine of the building. Labs are laid out in modules 11 ft
Nidus Center
Figure 1. floor pian of the building (courtesy of HOK Architects)
-------
LABS FOR THE 21ST CENTURY
wide by 33 ft long, and each laboratory is composed of
two modules. Each laboratory also has one enclosed office
with a large window that looks into the lab, and each lab
has a gas storage room.
Every laboratory faces either north or south, with
windows that take advantage of daylighting while provid-
ing a view to the outside. All the windows on the south
side include interior light shelves to reflect light into the
labs and exterior sun shades/overhangs. Offices for scien-
tists, building administrative functions, and building
functional support are on both floors along a curved wall
on the south side of the building. The floor plan for Level 2
is shown in Figure 1.
The building has a large, two-story interior atrium
adjacent to a naturally lit coffee bar/break area with an
adjacent outdoor shaded patio, as shown in Figure 2. In
the two-story spaces, angled and perforated metal exterior
sun shades block direct sunlight, but permit views of the
sky through the perforations.
A curved stone wall evokes the agricultural image of
the old stone barns of rural Missouri. Many details were
incorporated into the building to reflect the type of agri-
cultural and plant science research carried out in the facili-
ty. For example, corrugated galvanized metal is used as an
interior accent finish, as an exterior finish material around
the inset windows, and for rainwater-collecting cisterns.
Agricultural items such as weathervanes and watering
cans are artfully integrated into building's signage; some
signs were even designed to look like seed packages. A
view of the exterior showing the cisterns and exterior
overhangs for daylighting is shown in Figure 3.
The center's 24 laboratories were designed to accom-
modate one fume hood each, although currently only 10
labs use fume hoods. The building was designed primari-
ly to be a Biosafety Level 2 (BL-2) laboratory. BL-2 labs are
suitable for work involving agents of moderate potential
hazard to people and their environments.
Utility Servicing
Utilities run horizontally in the space above the ceil-
ings on both floors. The main air supply for the building
runs above the central hallway. The general exhaust ducts
run parallel to the supply air on both sides, in about the
middle of the labs. The fume hood exhaust runs parallel
in the horizontal ceiling space adjacent to the windows.
Boilers, chillers, air handlers, and 8-ft-high heat recovery
wheels are all in the building's basement. Industrial hot
and cold water, vacuum, natural gas, and potable hot and
cold water are piped through the ceiling to each lab bench.
There is a central reverse-osmosis deionized water system
Figure ?.. The Nidus Center's break room opens onto an
outdoor patio.
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-------
LABS FOR THE 21ST CENTURY
•I ductwork to deliver more or less air, as needed, for the
new function.
Materials
The design team specified regionally manufactured
brick and metal roofing. The earth fill/concrete, concrete
masonry unit (CMU) block, steel, drywall, doors, and win-
dow blinds were also available locally. Overall, more than
60% of the materials used in constructing the building
were acquired within a 300-mile radius, and more than
50% of the materials contain significant recycled content.
All the interior materials—including paint, adhesives, and
finishes—are low in VOCs. The waste management sub-
contractor separates materials and provides recycling off
site. Asphalt, concrete, metals, cardboard, and plastics
were all recycled.
Indoor Environmental Quality
Indoor air quality is enhanced by using 100% outside
air in the offices. It is also enhanced by a living wall of
indoor plants in the atrium, which provides natural air
filtration.
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LABS FOR THE 21ST CENTURY
wide by 33 ft long, and each laboratory is composed of
two modules. Each laboratory also has one enclosed office
with a large window that looks into the lab, and each lab
has a gas storage room.
Every laboratory faces either north or south, with
windows that take advantage of daylighting while provid-
ing a view to the outside. All the windows on the south
side include interior light shelves to reflect light into the
labs and exterior sun shades/overhangs. Offices for scien-
tists, building administrative functions, and building
functional support are on both floors along a curved wall
on the south side of the building. The floor plan for Level 2
is shown in Figure 1.
The building has a large, two-story interior atrium
adjacent to a naturally lit coffee bar/break area with an
adjacent outdoor shaded patio, as shown in Figure 2. In
the two-story spaces, angled and perforated metal exterior
sun shades block direct sunlight, but permit views of the
sky through the perforations,
A curved stone wall evokes the agricultural image of
the old stone barns of rural Missouri. Many details were
incorporated into the building to reflect the type of agri-
cultural and plant science research carried out in the facili-
ty. For example, corrugated galvanized metal is used as an
interior accent finish, as an exterior finish material around
the inset windows, and for rainwater-collecting cisterns.
Agricultural items such as weathervanes and watering
cans are artfully integrated into building's signage; some
signs were even designed to look like seed packages. A
view of the exterior showing the cisterns and exterior
overhangs for daylighting is shown in Figure 3.
The center's 24 laboratories were designed to accom-
modate one fume hood each, although currently only 10
labs use fume hoods. The building was designed primari-
ly to be a Biosafety Level 2 (BL-2) laboratory. BL-2 labs are
suitable for work involving agents of moderate potential
hazard to people and their environments.
Utility Servicing
Utilities run horizontally in the space above the ceil-
ings on both floors. The main air supply for the building
runs above the central hallway. The general exhaust ducts
run parallel to the supply air on both sides, in about the
middle of the labs. The fume hood exhaust runs parallel
in the horizontal ceiling space adjacent to the windows.
Boilers, chillers, air handlers, and 8-ft-high heat recovery
wheels are all in the building's basement. Industrial hot
and cold water, vacuum, natural gas, and potable hot and
cold water are piped through the ceiling to each lab bench.
There is a central reverse-osmosis deionized water system
Figure 2. The Nidus Center's break room opens onto an
outdoor patio.
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-------
LABS FOR THE 21ST CENTURY
Figure 3. Exterior view of the Nidus Center shows the cisterns
that store rainwater for irrigation and the exterior overhangs.
for the labs and a centralized glass wash and autoclave
capability.
Design Approach
A goal for the facility was to be designated a green
building by the USGBC. Because it was one of the first
LEED projects, the building's owner, designers and con-
tractors faced some challenges associated with pilot-
testing the newly designed LEED Version 1.0 certification
process. Several of the LEED credits—such as the need
to develop a construction waste management plan—
required the general contractor to develop new ways of
doing business. During the design process, the team mem-
bers used such tools as collaborative decision-making,
design charrettes, and energy simulation modeling. The
facility was successfully designed and built in 18 months.
Technologies Used
One major site consideration was the landscape
design. It introduced native plantings rich in color and
texture, such as native river birch, cinnamon fern, flower-
ing dogwood, and moonbeam coreopsis. No in-ground
irrigation system is needed, however. Reclaimed rain-
water from the roof is stored in cisterns to irrigate the
plants and grass.
Shower facilities in the building help to promote
alternative modes of transportation, such as bicycling.
Part of the site was once a parking lot. Now, however,
specially designated parking spaces are near building
entrances to promote carpooling.
Daylighting and Lighting
The building was designed to allow daylight in all lab
suites and public areas. Each tenant can make use of large
windows on both the north and south sides of the build-
ing. The windows on the south side are divided into two
sections. The lower section has tinted glass and exterior
sun shades to help reduce the impact of low-angle sun-
light. An internal horizontal overhang that also functions
as a light shelf allows light to penetrate deeper into the
building. The north windows, though large, do not need
tinted glass or overhangs for shading because of their
orientation.
The design of the interior ceiling in the labs helps to
make the daylighting more efficient. It is highest, at 12 ft,
along the north and south perimeter, and it slopes toward
the center of the space to a 9-ft-high ceiling. This design
also eliminates dark spots near the center of the ceiling.
The strategies all work together to maximize daylight in
the spaces. Figure 4 is a view inside a typical laboratory.
Public spaces in the building are naturally daylit by
an internal atrium with a skylight. Because of the atrium,
the connecting stair, coffee bar/break room, conference
rooms, corridors, and lobby are bathed in light. Hallways
include windows with views at each end. Windows in the
enclosed offices within the labs "borrow" the light in each
lab suite.
The connected lighting load is 1.4 W/gross ft2. The
electric lighting in each lab is controlled with multiple
switches to allow users to adjust artificial lighting, as
needed. The switching involves two levels in two zones.
Lighting in corridors is controlled with wall switches so
individual corridors can be switched off when a wing of
the building is unoccupied. Lighting in the atrium is con-
trolled with photocells and time clocks, to save energy.
Heating, Ventilation, and Air-Conditioning
The Nidus Center uses one integrated mechanical sys-
tem with energy recovery for labs and offices. The system
keeps general exhaust from the labs separate from fume
hood exhaust. Make-up air for the offices is 100% outside
air. It first cascades through the offices and then flows
through the labs.
According to the mechanical engineer, the enthalpy
wheels recover 80% of the heating and cooling energy
from this exhaust air stream and transfer it to the make-up
air stream. This is the energy equivalent of recirculating
-------
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' ' Mail Code 3404T
LABS FOR THE 21ST C E N T U R Y
i9nn
12°
Avenue, NW
202-566-0556
Figure 4. inside view o! a typical laboratory
80% of the general exhaust without the potential hazards
associated with actual recirculation. The use of 100% out-
side air in the offices results in a quantity of ventilation air
greater than that required by ASHR AE standard 62-89,
Labs have the 100% outside air required for safety. The
diagram in Figure 5 depicts the integrated system.
Fume hood exhaust is discharged in a dedicated
exhaust system. The labs use 10 air changes per hour,
as specified by the building owner. The fume hoods and
general supply and exhaust air system have variable-air-
volume (VAV) controls. The fume hoods all have a zone
presence sensor that sets back the
face velocity from 100 ft per
minute (fpm) to 60 fpm when the
lab is not occupied.
The two exhaust stacks have
integral fans and outside dampers
to entrain outside air and substan-
tially dilute the exhaust stream.
According to the manufacturer, the
exhaust nozzle design enhances
flow and pressure to increase out-
let velocities while minimizing
horsepower requirements.
Consolidating the entire build-
ing into one system lowered first
costs by minimizing the number of
air-handling units needed. The
integrated system uses two air-handling
R units for both lab and office areas, pro-
viding one fewer unit than conventional
systems, which have one air handler per
| office area and two per lab area. The
- resulting savings in equipment and
space, in comparison to the cost of a
conventional air-handling system, were
estimated at more than $100,000, In
addition, the energy recovery wheels
reduced both heating and cooling loads,
allowing smaller chillers, boilers,
pumps, and piping systems to be used.
These smaller components saved more
than $210,000; therefore, total first-cost
savings were about $310,000.
The amount of electricity needed for
cooling, gas for heating, and power for
utility distribution were all reduced by
this system. A DOE-2 computer simula-
tion analysis showed that the Nidus
Center would consume about 38% less
energy than a conventional building would, resulting in
annual energy cost savings of $60,000 at current rates. This
level of savings was confirmed in an examination of two
years' worth of utility bills.
An integrated HVAC system also provides flexibility.
Since labs and offices are on the same system, it is easier
to change from wet labs to dry labs, from labs to offices,
and from offices to labs over the life of the building. The
key is a single, integrated system serving both labs and
offices from the same main ducts. Conversion can be
accomplished locally by modifying boxes and room
Figure 5. Diagram of the Nidus Center's mechanical system
-------
LABS FOR THE 21ST CENTURY
ill-
I ductwork to deliver more or less air, as needed, for the
new function.
Materials
The design team specified regionally manufactured
brick and metal roofing. The earth fill, concrete, concrete
masonry unit (CMU) block, steel, drywall, doors, and win-
dow blinds were also available locally. Overall, more than
60% of the materials used in constructing the building
were acquired within a 300-mile radius, and more than
50% of the materials contain significant recycled content.
All the interior materials—including paint, adhesives, and
finishes—are low in VOCs. The waste management sub-
contractor separates materials and provides recycling off
site. Asphalt, concrete, metals, cardboard, and plastics
were all recycled.
Indoor Environmental Quality
Indoor air quality is enhanced by using 100% outside
air in the offices. It is also enhanced by a living wall of
indoor plants in the atrium, which provides natural air
filtration.
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'••"«"'•"•"'• •'""'"*'"" 1'5""'••'•'" ''• ••"••' ' i''- --~-•-•••'. - ••' -•'"' '''•
-------
LABS FOR THE 21ST CENTURY
Water Efficiency
Above-ground galvanized metal cisterns collect rain-
water from the roof and store it for irrigation. This system
saves water and associated pumping energy while reduc-
ing the load on drainage and storm-water systems. The
plumbing fixtures use 20% less water than that specified
in the water usage requirements of the Energy Policy Act
of 1992. The plumbing fixtures used include 1.6-gallons-
per-flush (gpf) toilets and 1-gpf urinals. The contractor
then adjusted the flows to 1.3 and 0.7 gpf, respectively.
Low-flow faucets and showers were also specified.
The cooling towers were designed to reduce drift and
evaporation.
Measurement and Evaluation.
Approach
The building manager monitors and tracks energy
bills to determine cost savings. The general contractor
performed the commissioning for the building to ensure
system performance.
Building Metrics
Table 2 summarizes the building's metrics and com-
pares the total annual estimated energy use to the actual
use shown in the energy bills. Actual measured energy
use, based on the two years' worth of energy bills, aver-
aged 322 kBtu/ft2/yr. The data reported in Table 2 are
for 2002 only, when energy use was slightly lower at
298 kBtu/ftVyr.
Metered data show electrical use in two categories:
(1) process/plug and lighting loads, and (2) ventilation
and cooling loads. The process/plug and lighting loads
account for 33% of the total electrical load, while ventila-
tion and cooling account for 66%.
The 38% savings represents the difference between
the ASHRAE 90.1 base case building, which was simulat-
ed at 517 kBtu/ft2/yr, and the two-year actual usage,
322 kBtu/ft2/yr. The building's actual total energy use
over two years was about 6% less than the 347 kBtu/gross
ft2/yr predicted by the simulation model. Annual energy
use data shown in the middle column of Table 2 are based
on estimates from the design parameters rather than the
simulation model except for heating energy, which was
taken from the simulation. The estimates in the table for
electrical uses are higher than the actual performance. The
estimate for heating is lower than actual performance.
Summary
The Nidus Center achieved a silver LEED rating for
its energy-efficient, green design. Because this was one of
the first pilot projects for LEED, the design team played
an important role in crafting the LEED methodology. The
building design process involved several highly effective
elements, such as an integrated team, collaborative deci-
sion-making, and design charrettes.
The design itself incorporates many energy-efficient,
sustainable design practices. The form and orientation of
the building—along an east-west axis with the long sides
facing north and south—were optimal for daylighting.
The daylighting system incorporates windows for views,
apertures for daylighting, internal and external light
shelves on the south side, and a sloped ceiling. The
mechanical system uses VAV controls on the fume hoods
and supply and exhaust air as well as an energy recovery
system. The building has rainwater cisterns to retain water
for irrigating the site and incorporates recycled and local
materials.
Energy use in the building is as designed—approxi-
mately 38% better than a conventional laboratory building
designed to the ASHRAE 90.1-1989 standard. Actual
metered data for the building demonstrate these energy
savings.
Acknowledgements
This case study would not have been possible without
the contributions of Kelly Jobe, Bill Odell, Robert
Barringer, and David Chassin of HOK Architects; Richard
Janis of William Tao & Associates, Consulting Engineers;
and David Broughton of the Nidus Center. The case study
was written by Nancy Carlisle and Otto Van Geet of the
National Renewable Energy Laboratory (NREL). Paula
Pitchford, editor, and Susan Sczepanski, graphic designer,
NREL, also contributed to this case study
-------
8
For More Information
On the Nidus Center:
David L. Broughton
Executive Vice President and Chief Operating
Officer
893 North Warson Road
St. Louis, MO 63141
314-812-8002
david.l.broughton@niduscenter.com
David Chassin, A.I.A.
HOK Architects
271 North Broadway, 6th Floor
St. Louis, MO 63102
314-754-4308
david.chassin@HOK.com
RichJanis,P.E.
William Tao & Associates, Inc.
349 Marshall Ave., Suite 200
St. Louis, MO 63119
314-961-5258
rrjanis@primary.net
On Laboratories for the 21st Century:
Phil Wirdzek
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W.
Washington, DC 20460
202-564-2094
wirdzek.phil@epamail.epa.gov
Will Lihtner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-4858
William .lin tner@ee. doe.gov
Nancy Carlisle, A.I.A.
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384-7509
Nancy_CarIisle@nreI.gov
Laboratories for the 21 st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.epa.gov/labs21 century/
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous future where energy
is clean, abundant, reliable, and affordable
www.eere.energy.gov/
Prepared at the
National Renewable Energy Laboratory
A OOE national laboratory
DOE/GO-102003-1772
Revised March 2005
Printed with a renewable-source ink on paper containing at least
50% wastepaper, including 20% postconsumer waste
i**Wi"W* *»-.-«
-------
LABORATORIES FOR THE 21si CENTURY
CASE STUDIES
Case Study index
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"'
;d',Reriewable3',,
WHITEHEAD BIOMEDICAL RESEARCH
BUILDING AT EMORY UNIVERSITY,
ATLANTA, GEORGIA
introduction
The eight-story Whitehead Biomedical Research Building, which was completed in 2001, is the
largest of its kind in the southeastern United States; it has incorporated many energy- and water-
efficient features. This new building at Emory University supports three science departments with-
in the School of Medicine—Cell Biology, Genetics, and Physiology. And an entire floor is devoted
,..;.,..., ,, , . , to interdisciplinary programs for the Departments of Neurology, Neurosurgery, Pathology and
rpesigrip^cesSrjvKy,:: ; J Laboratory Medicine, Psychiatry, and Behavioral Sciences.
.
Q ;0n-s|te ^generation !":: V ;
" '
Bulling o>miTij^oning]r -
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QGold--: '•-. '
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|V;-vVv>- -^Clili/r.^'^-.'.;:}
••?r~-^?h^v.:'rZ*wi:.M:l?i::~-;!i
oEPA
United States
Environmental
Protection Agency
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Federal Energy Management Program
-------
tj
LABS FOR THE '2 1ST CENTURY
This case study of the Whitehead Research Building
is one in a series produced by Laboratories for the 21st
Century, a joint program of the U.S. Environmental
Protection Agency (EPA) and the U.S. Department of
1| Energy (DOE). Geared toward architects and engineers
who are familiar with laboratory buildings, the case stud-
ies exemplify the "Labs 21" approach, which encourages
the design, construction, and operation of safe, sustain-
able, high-performance laboratories.
The energy and water efficiency strategies incorporat-
ed in the Whitehead Research Building's design and
construction reflect a significant commitment to environ-
mental stewardship on the part of both Emory University
and the design team. Emory University's new buildings
are guided by a comprehensive master plan that empha-
sizes sustainable design practices, which include creating
a pedestrian-friendly campus that replaces cars and con-
crete with greenspaces and walkways. This facility was
one of the first buildings at Emory to incorporate .new
architectural guidelines while integrating the design into
the context of a historic campus.
"We may be making just a small dent in local
environmental problems in the state of Georgia,
but what if everybody did the same?" John Wegner,
Emory University Campus Environmental Officer
These are some of the building's many sustainable,
high-performance features:
• Energy recovery^-The energy recovery system is made
up of four desiccant cooling enthalpy wheels, each
20 feet (ft) in diameter, that use air exhausted from the
facility to preheat the outside air in winter and to pre-
cool outside air in summer before it is drawn into the
building.
• Condensate recovery for cooling towers—Air-condi-
tioning condensate water is piped from the air-han-
dling units (AHUs) and chilled water coils back into
nearby cooling towers for use as make-up water. This
diverts an estimated 2.5 million gallons of condensate
water per year from the county's sanitary sewer and
reduces municipal water consumption at the central
plant. The resulting savings could supply 100 people
in the United States with their daily water needs for
125 days of the year.
* Rainwater harvesting for irrigation—Storm water
from the roof and the plaza is collected into an under-
ground storage vault and reused for irrigation.
•" Natural lighting and lighting controls—
Approximately 90% of regularly occupied spaces have
large windows for daylighting, saving energy that
would otherwise be consumed by the electric lights,
many of which are controlled by photo sensors and
motion detectors.
The building received a Leadership in Energy and
Environmental Design (LEED™) silver rating in 2002
from the U.S. Green Building Council. It also won an
Energy User News "Best New Project" Award in 2002,
and it received an Honorable Mention in 2003 from
Environmental Design + Construction magazine for
"Excellence in Design." The additional cost incurred to
achieve a LEED silver rating was about $990,000, or 15%
of the building's total construction cost. Emory's savings
in energy costs alone over the next decade will cover the
additional first cost.
Project Description
The Whitehead Biomedical Research Facility is an
eight-story, 325,000 gross ft2 (212,264 net ft2) laboratory
building that houses special facilities for tissue culture and
a vivarium. It was completed in October 2001, one month
ahead of schedule, at a total construction cost of $65 mil-
lion, or $200/gross ft2. The facility was designed by
Hellmuth, Obata + Kassabaum, Inc. (HOK) of Atlanta,
Georgia. The structural engineers were Standley D.
Lindsey of Atlanta, and the mechanical, electrical, plumb-
ing and fire-protection engineers were Nottingham,
Brooke and Pennington of Macon, Georgia. The Whitting-
Turner Contracting Company of Atlanta was the general
contractor and construction manager.
Layout and Design
The building includes 150 faculty offices and
150 laboratory modules built around the "open lab" con-
cept. This concept calls for large, flexible laboratory spaces
and fewer walls, resulting in a building designed for
greater interaction and better flow among researchers.
Dry benches are along the windowed walls. Corner break
rooms with dry-erase wall coverings were designed to
foster collaboration. The largest wing of the building is
oriented along an east-west access, which allows natural
light to enter the building from the north or south. The
facility supports both Biosafety Level (BL)-2 and BL-3
research activities.
'The basic planning module for the labs measures
10 ft x 39 ft. Laboratories are organized in open groups
of 10 modules each. The design allows for increases or
decreases in occupied square footage for individual
research programs, in response to changing program
-------
LABS FOR THE 21ST CENTURY
needs. This adjustment is accomplished by simply con-
necting individual laboratory modules via openings in
shared partitions. The large, open labs also allow multiple
research groups to work very near each other with mini-
mal separation. The interdisciplinary interaction benefits
all of the building's occupants.
Each open lab grouping has its own controls for light-
ing; heating, ventilation, and air-conditioning (HVAC);
and piping. Controls for these services are located outside
the lab. In addition to designing standardized modules for
the labs, the piping and HVAC are also modular in design
to allow the lab units to adapt quickly and respond to
changes in technologies, equipment, processes, and tech-
niques. The flexibility offered by this modular approach
allows Emory to change labs without affecting adjacent
spaces. The enhanced laboratory design greatly increases
the research efficiency of departments such as Cell Biology
and Physiology, which had been housed in buildings con-
structed in the 1920s before the new facility was built.
The third-floor plan is shown in Figure 1. A break-
down of space by function is shown in Table 1.
Utility Servicing
Figure 1 depicts the duct and pipe shafts and lab pip-
ing closets; this illustrates how utilities are integrated into
the building. Much of the work in the labs, up to 24 hours
per day, is done on the bench top rather than in fume
hoods. So, building energy loads are driven by the air
change rate, instead of by the number of fume hoods.
Table 1. Whitehead Biomedical
Research Building Space
Breakdown (Net ft?, unless otherwise noted)
Function
Labs (BL-2 and BL-3) and lab
support space
Office and program support
Environment, health, and safety
space
Vivarium
Total net ft?
Other®
Total gross ft?
SizeffP)
148,000
35,600
5,000
23,664
212,265
112,735
325,000
Percentage^
70%
17%
2%
11%
100%
Notes:
1. The percentage shows a breakdown of net ft2 only. Net ft* equals gross ft2
minus "other."
2. "Other" Includes circulation, toilets, stairs, elevator shafts, mechanical and
electrical rooms and shafts, and structural elements like columns.The net-to-
gross-tt2 ratio is 0.65.
The HVAC system was designed to operate at constant
volume and to include energy recovery; four enthalpy
wheels, each one 20 ft in diameter, are used. The building
has a general exhaust system and a separate fume hood
exhaust system. Only the general exhaust goes through
the energy recovery wheels.
(
o 16 32
Figure 1. Third-floor plan of Whitehead Biomedical Research Building at Emory University
-------
LABS FOR THE 21ST CENTURY
The general labs were designed for a ventilation rate
of 10 air changes per hour (ACH). The building has 69
chemical fume hoods. Each of the fume hoods uses a valve
to keep the airflow constant in case the duct static pressure
j!| varies. The building also includes 16 exhausted biosafety
iiSSSi cabinets. The cabinets in the BL-3 area connect to the fume
hood exhaust.
The vivarium was first designed for 15 ACH but was
redesigned to 10 ACH when ventilated cages were select-
ed for use in it. However, because the cages were not
scheduled to be available when the building opened, the
vivarium was redesigned back to 15 ACH. The cages were
added later. A portion of the vivarium's exhaust, from
rooms containing general animal housing, goes through
the general exhaust. Exhaust air from animal rooms that
contain contaminants or pathogens goes through the fume
hood exhaust system.
The vivarium exhaust represents about 4% of the total
volume of air exhausted through the energy recovery
wheels. At one point, however, it was found that the
vivarium exhaust didn't mix as well as expected with the
general exhaust, and some odors were being recirculated
back into the building. The lesson learned from that
experience was to reduce the ratio of vivarium exhaust
to general exhaust even further, to about 2%.
Chilled water is supplied to the building from a
chilled water plant. The tonnage of cooling required was
computed by allowing credit for the heat recovery from
the enthalpy wheels, with one wheel offline for service at
or near the peak design date. A central plant provides the
building with steam for heating.
Design Approach
From the start, the project design reflected a commit-
ment to sustainable design practices. However, achieving
the LEED silver certification did not become a design goal
until a few months after construction began in March 1999,
when Emory University decided to make LEED certifica-
tion mandatory for all new campus projects, starting with
the Whitehead Research Building. Typically, planning for
LEED certification occurs during the early stages of the
design process. In this case, however, the design team
was already sensitive to the need to save energy and water
and to integrate the building into an overall campus plan
emphasizing pedestrian movement. So, the design team
needed to incorporate only a few things to achieve a
silver rating.
The project delivery method was Construction
Manager At-Risk, with a fast-track, phased design docu-
ment process. After the construction of the first and the
second packages (the foundation and structure) of this
project were well under way, cost reports showed that the
completed project would be $6 million over budget. At
that point, the project team—including the designers, con-
struction manager, and owner—went through an intense
value engineering phase that lasted 2 months. During that
phase, the team kept its focus on the life-cycle cost of the
project. They worked hard to protect the features of the
building that made good business sense for the owner in
the long run, even though those features added to the first
cost. At the end of the value engineering phase, the project
team was successful in bringing the project within striking
distance of the budget.
Technologies Used
The building is on a site that had been developed
previously, increasing density without losing green space.
A greenhouse already on the site was relocated to another
site on campus instead of being demolished. The new
building is served by Emory's alternative transportation
system, with no net increase in parking and a reduction
in local vehicle emissions. To support this and other new
projects, Emory built a parking garage a few miles from
the campus. A new shuttle road served by alternatively
fueled vehicles—both compressed gas and electrical
ones—allows Emory to ferry people back and forth from
the parking area to the campus.
The university also has a policy that assures no net
loss of the tree canopy. This means that, for each tree
removed, one tree is planted elsewhere on campus.
Energy Efficiency
The primary strategy for energy efficiency is to
use the four 20-f t-diameter enthalpy wheels for energy
recovery. The enthalpy wheels recover heat energy from
exhaust air and use the air exhausted from the facility to
preheat outside air in the winter and to precool outside air
in the summer. The wheels are in a mechanical penthouse
room on the top floor of the building; this mechanical
penthouse is hidden from view by a sloped roof. The air
intake is below the eve of the roof. An exterior view of the
building is shown in the photograph on page 1.
The added first cost of the heat recovery system was
$450,000, with a simple payback of about 4 years. The
mechanical engineer convinced the design team of the
usefulness of this feature, and the owner had the foresight
to see that this was the right decision in the long run. Their
efforts helped to keep the wheels in the project during the
cost-cutting phase.
Return air from clean zones, such as offices, is mixed
back into the supply air so that supply air is approximate-
ly 75% outside air to all zones. This strategy saves on the
amount of air that needs to be conditioned.
-------
LABS FOR THE 21ST CENTURY
An energy analysis was performed to compare the
building as designed with a base case building meeting
American Society of Heating, Refrigerating, and Air-
Conditioning Engineers/Illuminating Engineering Society
of North America (ASHRAE/1ENSA) standard 90.1-1999.
Expected annual savings include 2161 MBru of heating
fuel and 3.4 million kWh of electricity, or $167,730 in
energy costs. This takes into account the savings from
daylighting controls and high-efficiency equipment. And
it translates into a 22.2% overall energy savings, when
compared with the base case.
System design decisions were made on a life-cycle
cost basis, and a "value management", process was
employed to ensure that cost-reduction decisions did
not reduce the facility's long-term value to the university.
For the energy recovery system alone, the internal rate of
return on a $450,000 investment yielding $136,028 annual-
ly over 10 years would be 28% (this assumes no escalation
in utility costs over that time). If costs and benefits of other
efficiency measures were taken into consideration, the
actual rate of return relative to a code-compliant facility
would be significantly greater.
The ventilated cages used in the viviarium provide
several opportunities for energy and material savings
and health benefits to occupants. The system used in the
Whitehead Building provides supply and exhaust air
directly to and from each individual cage. And the system
allows a reduction in the ventilation air rate from 15 ACH
to 10 ACH. In new construction, this could allow a reduc-
tion in the size of the fans serving the vivarium. The venti-
lated racks also keep the corncob bedding drier, so that it
must be changed only every 14 days rather than every
7 days. The ventilated racks provide health benefits for
workers and reduce the spread of allergens.
Daylighting and Lighting
Ninety percent of the building's lab and office spaces
line the perimeter and include windows to the outside.
Thus, the vast majority of occupied rooms receive natural
light during the day. The building's perimeter electric
lighting system is tied to an on/off switch controlled by a
photocell (with manual overrides) to control the row of
lights parallel to the window. These lights are automatical-
ly switched off when there is adequate natural lighting.
Each 2500-ft2 zone in lab areas has six 3-way switches
to control lights. Individual offices and small rooms use
motion detector lighting controls. The lighting inside the
building uses T-8 lamps with electronic ballasts in two-
lamp, 1x4 recessed parabolic fixtures located directly
over each bench. The lighting level at bench top is 75 foot-
candles.
Water Efficiency
Emory University incorporated several water-saving
measures into this project. These include storm-water
harvesting for irrigation, a condensate recovery system
for make-up water in cooling towers, and advanced
cage-washing techniques.
The building's storm-water harvesting system cap-
tures water from the roof and the outdoor plaza and
moves it to a large retention vault beneath the plaza. The
water is then filtered and reused for site irrigation. Fulton
County required Emory to build a retention vault to slow
down the runoff of storm water from the roof and the
site. When they decided to go for LEED certification, the
Emory design team made the underground retention
vault 3 feet deeper so it would hold about 70,000 gallons
of water. They also added a filter, a pump, and a bit of
piping to connect this catchment area into the site's
irrigation system. Figure 2 shows the retention vault
under construction.
In addition, the design team recognized that the air-
conditioning system would create a tremendous amount
of condensate water. So, they decided to pipe the conden-'
sate from the AHUs and chilled water coils back into
nearby cooling towers for use as make-up water. This
system not only conserves water, it also diverts an estimat-
ed 2.5 million gallons a year from the county's sanitary
sewer system, saving energy and money as well.
The vivarium includes a state-of-the-art, automated '
cage-washing system. The cage washer, which was manu-
factured in Finland, is one of the first ones installed in the
United States. It saves energy, water, and chemicals by
recycling water through four stages of cleaning using a
counter-current rinsing process. In counter-current rins-
ing, the flow of rinse water for cage washing is the oppo-
Figure 2. Retention vault
-------
8
LABS FOR THE 21ST CENTURY
Acknowledgements
This case study would not have been possible without
the contributions of Rohit Saxena, AIA, and Stuart Lewis,
AIA of HOK Architects in Atlanta, GA; Bill Nottingham,
PE, and Tim Trotter, PE, of Nottingham, Brook and
Pennington in Macon, G A; and Laura Case of Emory
University in Atlanta. The author is grateful to all of them
for contributing their expertise, time, and valuable assis-
tance. This case study was written by Nancy Carlisle of the
National Renewable Energy Laboratory with assistance
from Otto Van Geet, Paula Pitchford, editor, and Susan
Sczepanski, graphic artist, also of NREL.
For More Information
On the Whitehead Biomedical Research
Building:
Laura Case
Facility Manager
Emory University
638 Asbury Circle, Building C
Atlanta, G A 30322
404-727-5543
Icase2@fmd.emory.edu
Rohit Saxena, AIA
HOK, Science + Technology
235 Peachtree Street, N.E.
Suite 500
Atlanta, G A 30303
404-439-9222
rohit.saxena@hok.com
On Laboratories for the 21st Century:
Dan Amon, P.E.
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W. (3204R)
Washington, DC 20460
202-564-8234
amon.dan@epa.gov
Will Lintner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120 •
william.lintner@ee.doe.gov
Nancy Carlisle, AIA
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384-7509
nancy_carlisle@nrel.gov
Laboratories for the 21st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.labs21century.gov
In partnership with the
U.S. Department of Energy - • •
Energy Efficiency and Renewable Energy
Bringing you a prosperous Mure where energy is clean,
abundant, reliable, and affordable
www.eere.energy.gov
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
U S EPA Headquarters Library
Mail Code 3404T
1200 Pennsylvania Avenue, NW
Washinqton DC 20460
202-566-0556
DOE/GO-102005-2046
April 2005
Printed with a renewable-source Ink on paper containing at least
50% wastepaper, including 20% postconsumer waste
-------
LABS FOR THE 21ST CENTURY
An energy analysis was performed to compare the
building as designed with a base case building meeting
American Society of Heating, Refrigerating, and Air-
Conditioning Engineers/Illuminating Engineering Society
of North America (ASHRAE/IENSA) standard 90.1-1999.
Expected annual savings include 2161 MBtu of heating
fuel'and 3.4 million kWh of electricity, or $167,730 in
energy costs. This takes into account the savings from
daylighting controls and high-efficiency equipment. And
it translates into a 22.2% overall energy savings, when
compared with the base case.
System design decisions were made on a life-cycle
cost basis, and a "value management" process was
employed to ensure that cost-reduction decisions did
not reduce the facility's long-term value to the university.
For the energy recovery system alone, the internal rate of
return on a $450,000 investment yielding $136,028 annual-
ly over 10 years would be 28% (this assumes no escalation
in utility costs over that time). If costs and benefits of other
efficiency measures were taken into consideration, the
actual rate of return relative to a code-compliant facility
would be significantly greater.
The ventilated cages used in the viviarium provide
several opportunities for energy and material savings
and health benefits to occupants. The system used in the
Whitehead Building provides supply and exhaust air
directly to and from each individual cage. And the system
allows a reduction in the ventilation air rate from 15 ACH
to 10 ACH. In new construction, this could allow a reduc-
tion in the size of the fans serving the vivarium. The venti-
lated racks also keep the corncob bedding drier, so that it
must be changed only every 14 days rather than every
7 days. The ventilated racks provide health benefits for
workers and reduce the spread of allergens.
Daylighting and Lighting
Ninety percent of the building's lab and office spaces
line the perimeter and include windows to the outside.
Thus, the vast majority of occupied rooms receive natural
light during the day. The building's perimeter electric
lighting system is tied to an on/off switch controlled by a
photocell (with manual overrides) to control the row of
lights parallel to the window. These lights are automatical-
ly switched off when there is adequate natural lighting.
Each 2500-ft2 zone in lab areas has six 3-way switches
to control lights. Individual offices and small rooms use
motion detector lighting controls. The lighting inside the
building uses T-8 lamps with electronic ballasts in two-
lamp, 1x4 recessed parabolic fixtures located directly
over each bench. The lighting level at bench top is 75 foot-
candles.
Water Efficiency
Emory University incorporated several water-saving
measures into this project. These include storm-water
harvesting for irrigation, a condensate recovery system
for make-up water in cooling towers, and advanced
cage-washing techniques.
The building's storm-water harvesting system cap-
tures water from the roof and the outdoor plaza and
moves it to a large retention vault beneath the plaza. The
water is then filtered and reused for site irrigation. Fulton
County required Emory to build a retention vault to slow
down the runoff of storm water from the roof and the
site. When they decided to go for LEED certification, the
Emory design team made the underground retention
vault 3 feet deeper so it would hold about 70,000 gallons
of water. They also added a filter, a pump, and a bit of
piping to connect this catchment area into the site's
irrigation system. Figure 2 shows the retention vault
under construction.
In addition, the design team recognized that the air-
conditioning system would create a tremendous amount
of condensate water. So, they decided to pipe the conden-
sate from the AHUs and chilled water coils back into
nearby cooling towers for use as make-up water. This
system not only conserves water, it also diverts an estimat-
ed 2.5 million gallons a year from the county's sanitary
sewer system, saving energy and money as well.
The vivarium includes a state-of-the-art, automated
cage-washing system. The cage washer, which was manu-
factured in Finland, is one of the first ones installed in the
United States. It saves energy, water, and chemicals by
recycling water through four stages of cleaning using a
counter-current rinsing process. In counter-current rins-
ing, the flow of rinse water for cage washing is the oppo-
Figure 2. Retention vault
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6
LABS FOR THE 21ST CENTURY
Figure 3. Robotics used in cage washing operation
site of that of the workflow. In other words, the cleanest
water is used only for the final rinsing stage; water for
early rinsing tasks, in which the quality of rinse water is
not as important, is water that was previously used in the
later stages of rinsing operations. An automated process
using robotics disposes of the dirty bedding, feeds the
cages through a washer, fills the clean cages with clean
bedding, and replaces cages in the racks. This has elimi-
nated much of the manual labor associated with this task.
Figure 3 shows the robotics.
A central plant system is used for cooling. The cooling
load, and thus the amount of chilled water needed, is
reduced approximately 20% by the operation of the
enthalpy wheels.
Indoor Environmental Quality
To protect the building's indoor air quality, paints
and adhesives with low levels of volatile organic com-
pounds, or VOCs, were used, and it has been designated
a nonsmoking facility. During construction, a manage-
ment plan was implemented to prevent the contamination
of building materials by water, dirt, and other sources of
pollutants. Before the staff moved in, the office areas were
flushed with 100% outside air.
Materials
The building materials incorporate products (such as
lab counters) that are manufactured using post-consumer
and post-industrial waste. In addition, the construction
featured materials that are manufactured locally, reducing
energy used for transportation. Emory also followed a
construction recycling plan. They recycled 300 tons of
metal and saved about $20,000 by being conscientious
about recycling.
Measurement and Evaluation
Approach
Meters were installed at the main switchboard to
track electrical loads off individual feeder lines as well as
to measure the use of steam and water, including chilled
water. Electric power and steam usage is reported in
Table 2.
Commissioning
Emory's standard approach is to commission all new
buildings before they open for business. This includes
commissioning all the building systems to ensure that
they are operating in the intended ways. The owners
believe that, while commissioning improves the efficiency
of most buildings, it is especially important for laboratory
buildings, which use a large amount of energy and have
special safety requirements as well as sophisticated con-
trol systems, like fume hoods.
Building Metrics
In Table 2, data on annual energy use that was esti-
mated from design parameters is compared with actual
metered data summed from three electric meters and
metered steam data. The metered data were tabulated for
2 years for comparison purposes and were similar in both
years; the table shows annual data for May 2003 through
April 2004. Metered data are 20% lower than the estimate.
This is generally the case in laboratories featured in
Labs 21 case studies because the estimates are usually
conservative, and they take into account only very general
usage information. Since the cooling load at the central
plant was not accounted for by the building's electric
meters, an estimate for cooling was added to the data for
actual energy use measured at the building. Water use at
this facility was measured at 11,715,000 gallons per year.
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LABS FOR THE 21ST CENTURY
Table 2, Whitehead Biomedical Research Center Building Metrics
System
Ventilation (sum of
wattage of all the
supply fans and all the
exhaust fans)
Cooling plant
Lighting
Process/Plug
Heating plant
Total
*
Key Design Parameters
Supply = 1.0W/cfm
Exhaust =1.25 W/cfm
Tota) = 1.13W/cfm(i)
(1 .0 cfm/gross ft2; 1 .5 cf m/net ft2
and 2.1 cfm/gross ft2 of labs)<2)
2300 tons, 1.0kW/ton
1. 6 W/ft2 average
11 W/net ft2
Not available
Annual Energy Usage Estimate
(based on design data)
19.8kWh/grossffl(3}
s
20.4kWh/grossftz<4>
7.25kWh/grosstt2<5)
32.4kWh/grossft2(6)
Not available
79,85 kWh/grossft2/yr
(estimate based on design data
for electricity only)
272kBtu/grossft2/yrfor
electricity only
Annual Energy Use
(based on measured data)
NA
NA
NA
NA
68,298,447 pounds of steam
42.90 KWh/gross fftvr for electricity only (based
on metered data from 05/03 - 04/04)
Since cooling is provided by a central plant, the
estimate of 20.4 kWh/gross ftz/yr is added back in
Total electrical energy = 63.3 kWh/grossftz/yr
(222.6 kBtu/grossft2/yr)
Steam = 210 kBtu/grossft2/yr
432.6 kBtu/gross ft2 for electricity, cooling (est.)
and steam
Notes:
1. W/cfm for supply air=910 hp x 746 W/hp/681,000 cfm (supply) = 1.0 W/cfm; lor exhaust air = 530.5 hp x 746 W/hp/317,040 cfm = 1.25 W/cfm; average = 1.13
(based on nameplate rating data).
2. 317,040 cfm (total cfm based on exhaust)/212,265 net ft2 = 1.5 cfm/net ft2; 317,040 cfm/325,000 gross ft2 = 1.0 cfm/gross ft2; 317,040 cfm/148,000 net ft2 of labs
= 2,1cfm/nettt2oflabs.
3. 1.13 W/clm x 1.0 cfm/gross ft2 x 8760 hours x 2/1000 = 19.8 kWh/gross ft2 (30.5 kWh/net ft2).
4.1 kW/ton x 2300 tons x 2890 hours/325,000 gross ft2 = 20.4 kWh/gross ft2 (assumes cooling runs 33% of the hours in a year).
5. 1.6 W/gross ft2 x 4534 nours/1000 = 7.25 kWh/gross ft2 (2.46 W/net ft2 x 0.65 = 1.6W/gross ft2) (assumes lights are on 87.2 hoursSweek).
6. 7.71 W/gross ft2 x 0.80 x 5256 hours/1000 = 32.4 kWh/gross ft2 (11 W/net ft2 x 0.65 = 7.71 W/gross ft2) (assumes that 80% of all equipment is operating 60% of the
hours in a year).
7. Estimated data are presented in site Btu (1 kWh = 3412 Btu). To convert to source Btu, multiply site Btu for electricity by 3. Note: Atlanta has approx. 3069 heating
degree-days and 1611 cooling degree-days (based on weather data for Atlanta, GA).
Summary
The Whitehead Biomedical Research Building design
team was sensitive to the need to save energy and water
and to integrate the building into an overall, pedestrian-
friendly campus plan. These became key factors in the
success of this building as a high-performance laboratory.
The mechanical engineer advocated the use of energy
recovery wheels early in the process, and they are integrat-
ed effectively into the building's architecture under a
sloped roof. The design team also strongly emphasized
water efficiency by incorporating an underground water
storage vault for storm water to use in irrigating the site,
and by piping air-conditioning condensate from the air-
handling units and chilled water coils back into nearby
cooling towers for use as make-up water.
Emory.University's strong commitment to sustain-
ability is evident in building designs that are guided by
a comprehensive master plan for the campus that includes
replacing cars and concrete with green spaces and walk-
ways. Emory's tree canopy policy also makes it a leader
in the university community for environmental responsi-
bility. In addition, the university requires all new build-
ings to achieve a LEED silver certification rating.
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8
LABS FOR THE 21ST CENTURY
Acknowledgements
This case study would not have been possible without
the contributions of Rohit Saxena, AIA, and Stuart Lewis,
AIA of HOK Architects in Atlanta, GA; Bill Nottingham,
PE, and Tim Trotter, PE, of Nottingham, Brook and
Pennington in Macon, GA; and Laura Case of Emory
University in Atlanta. The author is grateful to all of them
for contributing their expertise, time, and valuable assis-
tance. This case study was written by Nancy Carlisle of the
National Renewable Energy Laboratory with assistance
from Otto Van Geet, Paula Pitchford, editor, and Susan
Sczepanski, graphic artist, also of NREL.
For More Information
On the Whitehead Biomedical Research
Building:
Laura Case
Facility Manager
Emory University
638 Asbury Circle, Building C
Atlanta,G A 30322
404-727-5543
Icase2@fmd.emory.edu
Rohit Saxena, AIA
HOK, Science + Technology
235 Peachtree Street, N.E.
Suite 500
Atlanta, G A 30303
404-439-9222
rohit.saxena@hok.com
On Laboratories for the 21st Century:
Dan Amon, P.E.
U.S. Environmental Protection Agency
1200 Pennsylvania Ave., N.W. (3204R)
Washington, DC 20460
202-564-8234
amon.dan@epa.gov
Will Lintner, P.E.
U.S. Department of Energy
Federal Energy Management Program
1000 Independence Ave., S.W.
Washington, DC 20585
202-586-3120 •
william.lintner@ee.doe.gov
Nancy Carlisle, AIA
National Renewable Energy Laboratory
1617 Cole Blvd.
Golden, CO 80401
303-384-7509
nancy_carlisle@nrel.gov
Laboratories for the 21st Century
U.S. Environmental Protection Agency
Office of Administration and Resources Management
www.labs21 century.gov
In partnership with the
U.S. Department of Energy
Energy Efficiency and Renewable Energy
Bringing you a prosperous future where energy is clean,
abundant, reliable, ami affordable
www.eere.energy.gov
Prepared at the
National Renewable Energy Laboratory
A DOE national laboratory
U S EPA Headquarters Library
Mail Code 3404T
1200 Pennsylvania Avenue, NW
Washington DC 20460
202-566-0556
DOE/GO-102005-2046
April 2005
Printed with a renewable-source Ink on paper containing at least
50% wastepaper, including 20% postconsumer waste
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