Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
EPA Publication 909-F-07-001
What? Energy use in healthcare facilities is higher than nearly all other building types.
With rising energy costs and climate change concerns energy efficiency is
financially prudent and increasingly expected. Efficiency can be gained from
integrated design practices, including systems to control heat gain, and increase
the efficiency of heating, ventilation, and air conditioning (HVAC) systems.
Why? Enhanced Community Reputation:
• Increases energy efficiency and
reduced climate impact
• Demonstrates environmental
stewardship
Environmental /Staff/Patient Benefit:
• Improves patient and staff comfort
with less intrusive indoor environment
Cost Competitive:
• Lowers HVAC size and rating through
integrated design
• Improves facility's overall operational efficiency
• Reduces operational costs
How? • Use integrated design (viewing building systems as interrelated instead of
separate)
• Focus on building envelope
• Perform energy audit of existing facilities (consider using ENERGY STAR for
Healthcare; www.energystar.gov)
• Model and plan energy use for new buildings
• Use benchmarking data
• Use high-efficiency HVAC, chiller, and variable speed pumps
• Install high performance windows
Case " Emory University
Studies " University of Florida
Green Guide for Health Care (GGHC) Criteria: Construction: Energy & Atmosphere and Operations: Energy
Efficiency www.gghc.org
This is one of 5 Building Healthy Hospitals case studies developed by EPA's Pacific Southwest Regional Office,
with Resource Conservation Challenge and Pollution Prevention funds.
www.epa.qov/reqion09/waste/p2/pro1ects/hospart.html
Indoor Air • Sustainable Flooring • Process Water Efficiency • Lighting Efficiency • Energy Efficiency
Building Healthy Hospitals 1
This fact sheet was produced by EPA's Pacific Southwest Regional Office. Mention of trade names, products, or services does not
convey, and should not be interpreted as conveying official EPA approval, endorsement, or recommendation.
Printed on 100% recycled paper, 50% post-consumer content - process chlorine-free
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
CASE STUDY 1: HIGH EFFICIENCY CHILLERS
Applicability:
Environmental
Impact:
Other Benefits:
New construction or major renovation projects.
• 40 to 50 percent reduction in energy use required
for space cooling
• 48 percent savings in cooling tower energy use.
Long term operating efficiency.
Background
Electrical centrifugal water chillers (chillers) represent the single largest
electrical load in most institutional and commercial facilities, accounting
for 35-50 percent of a building's annual electricity use1. Though chillers
generally operate below full-load, chillers are rated at full load efficiency,
application part load value (APLV), and integrated part load value
(IPLV). To reduce long-term operating costs, Emory installed two 350-
ton high efficiency chillers with a coefficient of performance (COP) of 5.2 at the Winship
Cancer Institute. The high efficiency units run in parallel and are connected to one of
Emory's four chiller plants, using 0.676 kilowatt-hours (kwh) per ton of cooling produced.
Performance
Emory recently began metering the chillers separately to determine actual kilowatt tons per
hour per square foot (kwh ton/hour/square foot). To adjust for differences in climate, this
data was divided by the degree cooling days for the month, providing a normalized metric
that can be compared to facilities elsewhere in the country (see Exhibit 3). Exhibit 4
compares Emory's chillers to commonly used efficiency standards.
The chillers are included in the preventive maintenance and leak detection program for
other equipment on campus and data is recorded and analyzed using a computer program.
The chillers at Winship Cancer Institute use refrigerant R134A, a non-ozone-depleting
chemical used in high-pressure systems. Purge systems are primarily used in low-pressure
chillers; therefore, this maintenance activity is eliminated for Winship Cancer Institute. No
additional unique maintenance activities are required to operate the high efficiency chillers;
therefore, the operation and maintenance (O&M) costs are comparable to standard chillers.
Emory has established detailed design and construction specifications—applicable to all
construction and major remodel projects on campus—that include requirements for
"Supply Side Focus: Chiller Equipment; The Elements of Energy Efficiency." Maintenance Solutions, August
2004. Online: www.facilitiesnet.com/ms/article.asp7id = 1833
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
purchasing chillers2. In addition to design and operating features, Emory requires all new
building on campus to use construction design specifications reflecting various green and
energy efficiency requirements; for chillers, Emory's specifications are as follows:
• Have minimum full load and part load efficiencies meeting or exceeding ASHRAE
Standard 90.1-20043 (specifications allow the project manager to require a more
stringent efficiency, as needed).
• Are manufactured by Carrier, Trane, or York (York chillers were selected for
installation at the Winship Cancer Institute).
EXHIBIT 3 | WINSHIP CANCER INSTITUTE NORMALIZED CHILLER ENERGY USE
,—, U.Ub
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• Chiller
D Chiller
2
1
July
June
May
April
Emory 2006 Design and Construction Standards, online: www.fm.emorv.edu/emorv-
std/2006%20Emorv%20DesiQn%20&%20Construction%20Standards.pdf
ASHRAE Standard 90.1 (2004) available online at:
www. realread.com/prst/paaeview/browse.cai?book= 1931862664
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
EXHIBIT 4 | EMORY CHILLERS VERSUS FEMP CHILLER EFFICIENCY RECOMMENDATIONS
Centrifugal
Chiller Size
150-299 tons
300-2,000 tons
Part Load Optimized Chillers
ASHRAE
Standard
0.78
0.66
Note: IPLV = Integrated Part
FEMP = Federal Energy
Adapted from "How to
January 2004. Online:
American Society of He
online: http://www.ash
FEMP
IPLV
0.52 or less
0.45 or less
Best
Available
IPLV
0.47
0.35
Full Load Optimized Chillers
ASHRAE
Standard
0.84
0.68
FEMP
Full-Load
0.59 or
less
0.56 or
less
Best
Available
Full-Load
0.50
0.47
Winship
(350 tons)
0.676
Load Value
Management Program
Buy an Energy Efficient Water-Cooled Electric Chiller," Department of Energy,
http://wwwl.eere.enera.v.aov/femp/pdfs/wc chillers.pdf.
ating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) Standards available
rae.org/.
Cost
High efficiency chillers are designed with enhanced controls, improved condenser sections,
and high-efficiency compressors; these features raised the initial cost to Emory by about 20
percent more than a comparable standard unit. However, the use of these chillers-
combined with the lower demand for chiller water through other energy conservation
measures—resulted in a 42 percent reduction in the energy required for space cooling and a
48 percent savings in cooling tower energy use. Emory estimates the simple payback from
using the new chillers instead of units with standard energy efficiency at less than 4 years
(see Exhibit 5).
The simple payback for recovering the cost premium of the chillers is directly related to the
cost of energy. At $0.05 per kilowatt-hour (kwh), Emory's energy costs are low compared
to elsewhere in the United States. In addition, Emory's energy costs are low despite recent
annual increases; costs have increased from $33.30 per megawatt-hour ($0.033/kwh)
between 2001 and 2006 (natural gas prices have more than doubled during this time as
well). As energy prices increase, Emory has been able to cost-justify more efficient
equipment with a higher cost premium. At many other institutions and in many other parts
of the U.S. higher costs could easily yield payback periods for the cost premium of 1.0 year
or less.
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
EXHIBIT 5 | COST/BENEFIT ANALYSIS - WINSHIP CANCER ENERGY-EFFICIENT CHILLER
Annual
Hours of
Operation
7,000
Standard ASHRAE
Efficiency
Annual
kwh
2,183,751
Annual
Cost
$109,187
Winship Cancer
Institute High-
Efficiency
Annual
kwh
1,263,387
Annual
Cost
$63,169
Cost
Premium
$100,000
Annual
Savings
$46,018
Payback
(years)
2.17
Note: Emory University energy costs approximately $0.05 per kwh in 2006.
The chillers at the Winship Cancer Institute operate at 70% average load.
Case Study Vitals
The following summarize success criteria for implementing this project at other healthcare
facilities:
Develop or Adopt Green Design Standards - Emory's detailed design and
construction specifications provide the University with a clear path to implementing
energy efficiency strategies on every project. Further, Emory requires the standards
as the "default" specifications for all buildings on campus. Though Emory's
standards generally follow LEED standards, other organizations can adopt standards
wholesale or modify them to suite their needs.
Establish Multi-Disciplinary Team - Healthcare facilities should ensure that its
design team encompasses several disciplines so that collectively the design team
understands expectations for energy efficiency projects and purchasing requirements
for energy-intensive systems.
- Know Your Organizations Investment Parameters - Chillers are available in a
variety of efficiency ratings with more efficient units coming with progressively
higher initial costs. The cost premium acceptable to a healthcare facility for
purchasing an energy-efficient chiller typically depends on cost/benefit analyses
(e.g., simple payback, internal rate of return) of the investment appropriate for the
institution. Designers of healthcare facilities typically have the benefit of using very
long "useful life" design horizons. In addition, areas with higher energy costs or
increasing energy costs will realize shorter payback.
No Additional Installation or Operation Issues - Emory has used high efficiency
chillers for several years with no additional installation or maintenance issues or
concerns.
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
CASE STUDY 2: HIGH EFFICIENCY AND VARIABLE-SPEED PUMPS
Applicability: New construction or major renovation projects
Environmental
Impact:
Other Benefits:
40 percent reduction in energy use required for pump
systems
Long-term operating efficiency
Background
Pumps serve a variety of purposes in HVAC systems, but primarily
function to move air or water within the system to control temperature.
Pumps have conventionally been designed to operate at a single-speed,
using the same amount of energy at all times of operation regardless of
load demand. Manufacturers have begun offering improved efficiency
pumps in two ways:
• Designing pumps with efficiency ratings 20 to 40 percent higher
than standard new models.
• Including variable-speed motors that operate with variable energy loads depending
on the amount of air or liquid that must be circulated at any given time, using only
what energy is needed.
Performance
Emory's Winship Cancer Institute uses high-efficiency, variable-speed pumps to pump: (a)
chilled water to the air handling units, and (b) condenser water from the chillers to the
cooling towers. A computer system installed in the building controls the pumps, monitoring
differential pressure to monitor load increases and decreases and set pumping requirements
accordingly; in this way the pump output (and therefore the energy input) changes to
match the HVAC requirements at the particular time of day.
Energy use associated with the pumps is estimated at 40 percent less than a typical facility
of comparable size (see Emory's calculations using USGBC's LEED Calculator 2.0 results in
Attachment A). The savings in pump energy is due not only to the use of variable speed,
high-efficiency pumps, but also to HVAC equipment efficiency differences and energy
recovery methods. These HVAC system improvements resulted in a smaller amount of
chiller water being handled by the pumps. As a result, the pumps operate less frequently
and more efficiently, significantly reducing overall energy use.
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
Cost
Emory installed the pumps as part of the new building construction at Winship Cancer
Center.
EXHIBIT 6 | HIGH-EFFICIENCY, VARIABLE SPEED PUMP FEATURES
Energy savings from pumps alone in the HVAC system is unavailable, but based on
vendor data and operational history, Emory estimates payback of pumps at
approximately 3 years.
Variable-speed high-efficiency pumps have operating efficiency 40 percent better
than standard new pumps
Energy savings of approximately 205 kwh per year (LEED Calculator 2.0 estimate)
Note: Emory University energy costs approximately $0.05 per kwh in 2006.
Pumps operate approximately 7,000 hours per year.
4_i_jr I Case Study Vitals
The following summarize success criteria for implementing this project at other healthcare
facilities:
Look for Additional Benefits Accruing to Other Systems - Improving efficiency
in building systems can have a waterfall effect, reducing the energy demands in
other related systems. For example, in Emory's case HVAC equipment efficiency
differences and energy recovery methods decreased the demand for chilled water,
also reducing the frequency pumps must operate. It is important to understand the
effects energy- and water-efficiency strategies will have on other systems and make
design decision using more efficient operating assumptions.
• Smaller Pumps are Good Candidates - Emory found payback on larger pumps
(more than 10 HP) not as attractive because of the run duration and cycling.
No Additional Installation or Operation - Emory has found no additional
installation or maintenance issues or concerns with the variable speed pumps and
has been using them successfully in numerous buildings across campus for many
years.
Building Healthy Hospitals 200?
An EPA P2 Project 7
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
CASE STUDY 3: LOW-E WINDOWS
Applicability:
Environmental
Impact:
Other Benefits:
New construction or major renovation projects;
windows selection is based on location and climate of
facility, as well as the building design and window
position
30 to 50 percent reduction in energy use
Long term operating efficiency; improved access to
daylight and natural views for occupants without
increasing energy costs for heating and cooling
Background
Windows are a critical part of the building envelope and provide
considerable aesthetic value to building occupants by introducing natural
light and providing a visual connection to the outside environment.
However, windows can also represent a large source of heat gain or loss.
Unmanaged solar energy can increase the heating load of the building,
demanding more of the air conditioning systems. Similarly, windows with
a poor ability to keep heat in allow warm air to escape the building in the
winter, increasing the demands on heating systems.
Window manufacturers have developed many new insulating and glazing techniques to
improve the performance of windows. The National Fenestration Rating Council defines five
performance areas to consider when choosing windows most suited for your local climate4:
U-Factor measures how well a product prevents heat from escaping a home or
building. U-Factor ratings generally fall between 0.20 and 1.20 with lower numbers
indicating a product better at keeping heat in.
• Solar Heat Gain Coefficient (SHGC) measures how well a product blocks heat from
the sun from entering the building. SHGC is expressed as a number between 0 and
1, with a lower SHGC indicating a product that is better at blocking unwanted heat
gain.
• Visible Transmittance (VT) measures how much light comes through a product. VT is
expressed as a number between 0 and 1 with a higher VT indicating higher potential
for daylighting.
"The Facts About Solar Heat Gain and Windows." National Fenestration Rating Council; online at:
www.nfrc.orQ/documents/SolarHeatGain.pdf
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
• Air Leakage (AL) measures how much outside air comes into a home or building
through a product. AL rates typically fall in a range between 0.1 and 0.3 with a
lower AL indicating a product that is better at keeping air out.
Condensation Resistance (CR) measures how well a product resists the formation of
condensation. CR is expressed as a number between 1 and 100 with a higher CR indicating
a product better able to resist condensation.
More so than other green building strategies, window selection must be tailored to the local
climate of a facility and building orientation. For example, facilities in warmer climates
should install windows with a lower SHGC and those in a cooler climate should install
windows with a lower U-factor. Low-e windows can be applied in different ways specific to
local climates and heating and cooling needs. Low-e coatings applied to exterior
windowpanes prevent heat gains from exterior radiation; whereas low-e coatings applied to
interior windows prevent heat loss. Manufactures often offer several low-e coatings with
varying degrees of solar gain.
Performance
Both Emory's Winship Cancer Institute and the University of Florida's Sports and Orthopedic
Surgery and Sports Medicine Institute installed low-e windows throughout their facilities.
Exhibit 7 compares the products installed at each facility against the ASHRAE 90.1 standard.
EXHIBIT 7 | CASE STUDY LOW-E WINDOWS VERSUS ASHRAE 90.1 STANDARD
ASHRAE 90.1
Emory - Winship Cancer Inst.
U of F - Orthopedic Surgery
and Sports Medicine Institute
U-COG
0.571
0.370
0.38
SHGC
0.404
0.372
0.380
VT
0.732
0.328
Not Available
SC
0.43
0.47
0.42
Note: U-COG: U-Factor at center of glass
SHGC: Solar heat gain coefficient
VT: Visible transmittance
SC: Shading coefficient
Emory installed low-e windows throughout the Winship Cancer Institute to reflect the sun's
radiant energy and reduce heat entering the building. Low-e interior glass was purchased
from Viracon, Inc. and low-e windows and curtainwall systems were purchased from EFCO.
These windows drastically reduced the cooling requirements of the building, but also
resulted in a slight increase in heating needs during the winter months. Because both the
buildings at Emory and the University of Florida are located in a humid, subtropical climate,
the slight increase in heating needs was easily compensated for in the reduced cooling
needs due to the installation of low-e windows.
Building Healthy Hospitals
An EPA P2 Project
2007
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
Cost
Windows manufactured with low-e coatings typically cost about 10 to 15 percent more than
regular windows, but they reduce energy loss by as much as 30 to 50 percent5.
Furthermore, this improvement in the building envelope—particularly when coupled with
other strategies that improve the efficiency of the building envelope—ultimately impacts the
demands of building HVAC systems. These benefits should be included in evaluating the
lifecycle costs of installing efficient windows.
EXHIBIT 8 | 2005/2006 ENERGY USE DENSITY - HEALTHCARE FACILITIES:
UNIV. OF FLORIDA ORTHOPEDICS CENTER
EMORY WINSHIP CANCER CENTER
• Windows with low-e coatings vary widely in cost depending on performance, glazing,
and other factors; generally the price premium is 10 to 15 percent, approximately the
cost premium for the buildings at both Emory and the University of Florida.
Low-e coatings reduce energy loss from 30 to 50 percent.
Neither Emory nor the University of Florida have data on energy reduction specifically
from the windows.
Univ. of Florida Orthopedic Center:
Energy use density for the Orthopedic Center varies between 210 to 380
BTUs/day/square foot; the building contains 46 exam rooms with support services of
Radiology, Rehabilitation, and Biomechanics representing a relatively equal mix of
patient rooms, offices, and therapy rooms. The building's energy use density is
approximately 50 percent lower than other medical building on campus (though the
comparable buildings contain more energy-intensive diagnostic equipment).
Univ. of Florida Energy management staff estimate that approximately 20 percent of
that energy efficiency at the Orthopedic Center is the result of the windows used in the
building based on their experience managing energy across campus and data provided
by the window vendor and architect.
Emory Winship Cancer Center:
Energy use density for Winship Cancer varies between 560 to 680 BTUs/day/square
foot; the building contains a large amount of energy-intensive treatment and patient
care equipment along with patient rooms and offices. Comparisons to other buildings at
Emory are difficult because of the lack of similar activities occurring elsewhere.
• Emory Building Management staff estimate the simple payback of the windows used in
the building at approximately 7 years.
5 "Low Emissivity Window Glazing or Glass." U.S. Department of Energy Efficiency and Renewable Energy.
Online: www.eere.enerav.Qov.
Building Healthy Hospitals 200?
An EPA P2 Project 10
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
400
350
300
250
200
150
Univ. of Florida Orthopedics Center - Energy Use Density
[BTUs/day/square foot]
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Note: University of Florida energy costs are $0.954 per kwh in 2006.
Winship Cancer - Energy Use Density
[BTUs/day/square foot]
750
Energy Density
2006 Energy Density
500 r-
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Note: Emory energy costs are $0.05 per kwh in 2006.
Case Study Vitals
The following summarize success criteria for implementing similar projects at other
healthcare facilities:
Building Healthy Hospitals
An EPA P2 Project
2007
11
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Energy Efficiency: Integrated Design and HVAC Systems
HEALTHCARE - TOP 5 GREEN BUILDING STRATEGIES
Efficient windows are defined by the climate of the building in which they will be
installed. Engineers and vendors are able to make recommendations based on local
climate and building orientation.
Efficiency improvements to the building envelope directly impact the heating and
cooling needs of the building; therefore, HVAC systems should be adjusted
accordingly to account for decreased demands on the systems.
Building Healthy Hospitals 200?
An EPA P2 Project 12
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