S-EPA
United States
Environmental Protection
Agency
Air and Radiation
(6202J)
EPA 430-K-96-001
April 1996
ENERGY STAR Buildings
Tech Tips
BUILDINGS
Sffi/iNGlhE EARTH. SAViNG^VbUR MONEY:
Building Tune-Up
Findings and Results
Stage 2
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
INTRODUCTION
This Tech Tip was developed using results from the
EPA Energy Star Buildings Program, a voluntary
program that prevents pollution by encouraging enejgy
efficiency in commercial buildings. Building on the
successful Green Lights energy-efficient lighting
program, Energy Star Buildings bases its success on
proven technologies that are profitable investment
opportunities. A central component of the program is a
stage-by-stage implementation process that takes
advantage of the system interactions and enables
building owners to achieve additional energy savings
while lowering capital expenditures. The stages of this
process are summarized in the box below
As many building owners entering the Energy Star
Buildings program have already implemented Green
Lights upgrades, a "tune-up" is often the first step. Even
new buildings can use improved controls and
operational strategies to reduce energy consumption. To .
document and verify the Energy Star Buildings strategy,
EPA signed an agreement with 24 organizations to
become Showcase Partners and implement energy
efficient upgrades in one building in one year. The
Showcase buildings demonstrate that small investments
in operational arid maintenance activities can provide a
large return for buildings and benefit the environment
by reducing greenhouse gas emissions.
Stage 1 Stage 2
Stages
Stag© 4
Stage 5
Green Building HVAC Load Improved Fans
Lights Tune-Up Reductions and Air-Handling
Systems
Improved
Heating and
Cooling Plant
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
This can be accomplished through a comprehensive,
structured energy survey of a facility where partners
determine which energy-saving modifications and
upgrades will be profitable. Based; on survey results,
Partners start with low-cost adjustments and tune-ups to
existing building systems. Partners also review and
improve preventative maintenance programs and train
building personnel on keeping the building's systems
working at peak efficiency.
EPA's experience has shown that these tune-up steps can
save significant amounts of energy as well as
significantly improve indoor air quality and occupant
comfort
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ENERGY STAR Buildings Tech Tips
Building Tune-lip
SHOWCASE SUCCESS
Tune-up measures were successfully implemented in many Energy Star Showcase-
buildings and in many cases tune-ups were able to provide immediate savings which
aided in funding energy efficiency measures in later stages. Table 1 summarizes the
key building characteristics (floor area and energy consumption) for Showcase
buildings where tune-ups were implemented, and the level of costs and savings which
were associated with the tune-up measures. The tune-up performed by Honeywell will
be the focus of this report The tune-up measures performed by the other Showcase
Partners are summarized in this section.
Table 1. Summary of Showcase Buildings Tune-up Savings
£XV< ^^^ "> s> fs">f > "
."Showcase, ' ',,,! >'" " 4
"* 's s $v> .** 2f\J>t&^*f
"Partaer ^ ^ ?^-
, -. ^w. ₯>s, '> xvt.. y-«- >
Douglas County,
OR
Honeywell Inc.
MN
J.C Penney GA
Louisville MSD
KY
Mobil Corp
VA
Mobil R&D
TX
Montgomery
County, MD
Warner Lambert
NJ
W*fV<,
|3!F^"M
Gov.
Office
Office
Retail
Office
Office
Off/Lab
Gov.
Office
Office
Sqiaaase
'i^eel^f -' "^
s ? f f
254,000
958,000
161,540
64,000
605,000
220,000
84,000 .
125,000
..Annual v
^±'*xt<'- '?<--? -
^cm #,,/^
5,343,800
16,993,000
9,105,000
1,816,000
6,178,000
15,500,000
3,722,000
2,726,000
\ ^Fmne^'ai)*
i&QSt? < ' ',-
$12,500
$108,785
$3,100
$10,400
$12,100
$69,000
$54,770
$2,410
Animal
$37870
$62,560
$5,450
$3,409
$24,200
$16,000
$10,260
$4,250
.**-: -
31%
58%
176%
32%
200%
23%
19%
176%
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
Douglas County, Oregon:
For this Showcase project, involving a courthouse and a jail, Douglas County replaced
their old Energy Management System (EMS) with a newer system and added energy
saving controls strategies. The new strategies included adding chilled water, condenser
water and hot water resets, optimal start/stop, duty cycling and demand shaving, and
pre-cool and pre-heat Chilled water and hot water temperatures are calculated based
on complex formulas integrating outside air temperatures, space demands, and
seasonal schedules. During simultaneous cooling/heating periods, the chillers are duty
cycled between full load operation and off. Low temperature chilled water is provided
for cooling while waste heat from the chiller is used to provide warm air to spaces that
need heating. During the cooling season, the chiller provides a variable chilled water
temperature based on outside air temperature and the previous day's load. During the
heating season, the boilers shut down if the outside air rises above 55 °F and there is
enough solar incidence (measured with ah insolator) to provide envelope heating.
Additionally, Douglas County uses a card-access system to measure occupancy in
specific zones and adjusts airflow and lighting provisions accordingly. This has not
only minimized overheating and cooling, but has also decreased comfort complaints.
Lessons Learned: Significant savings can be achieved without a major investment using an EMS
and integrating controls. A strategy which uses ambient conditions and occupancy schedules
to provide only the cooling and lieating necessary for individual zones maximizes energy
reduction while maintaining comfort levels
J.C. Penney
This Showcase building is a department store in Atlanta, GA. The tune-up measures
included coil cleaning and sensor replacements and additions. Thermocouples were
relocated and humidity sensors were added to improve the comfort control. Some
problems discovered during the tune-up survey were rectified as a result of HVAC
equipment replacement associated with other Showcase upgrades. For instance, during
the audit, the cooling tower was found to leak water, wasting about $1,000 per year.
The Showcase upgrades included replacement of the cooling tower, which eliminated
this problem.
Lessons Learned: This building was very well operated, and therefore few improvements were
identified. Tliefew measures implemented paid for themselves in less than a year. Improved
operation is yet anotlier benefit of replacing old equipment with energy efficient equipment
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
Louisville Metropolitan Sewer District
This Showcase building underwent complete renovation during the Showcase process.
The building was converted from what was a bank to office space. During this
renovation it had already been decided to convert operations from pneumatic controls
to direct digital controls (DDC). Several additional strategies were added as a result of
participation in the Showcase program, including winter night setback, optimal fan
start-up mode, and outside air damper controls.
Lessons Learned: Tune-up strategies are not limited to retrofits of existing buildings. Control
strategies far buildings under renovation or new construction can also prove to be -profitable, .
usually at little incremental cost.
Mobil Corp.
This Showcase building is a two-tower office complex in Reston, Virginia containing
offices for Mobil Corporation. The facility was constructed in 1990-1991, and included a
sophisticated EMS. Tune-up measures were identified in one of the tower buildings.
Besides an air balancing and thermostat calibration/ during the Showcase process a
supply air reset and optimal start/stop was added. After each Energy Star Buildings
upgrade stage (starting with Green Lights) they experimented with reset to
accommodate for the associated load reduction.
Lessons Learned: Even newer, well maintained buildings can expect energy savings by following
the staged strategy. Continuous monitoring and load measuring during the upgrade process
and afterwards can be used to shift set points, which minimizes energy consumption while
providing adequate comfort levels.
MobilR&D
This Showcase building is a research facility in Dallas, Texas. The tune-up involved
several changes to the air handling units. A walk through revealed that water coils
were piped incorrectly (providing parallel flow instead of counter-current flow), and
that problems with the pneumatic system were resulting in excessive reheat Mobil
organized a team of management, facilities operators, and outside consultants to
maximize energy reduction with the tune-up while maintaining inside comfort levels.
Two air handling units Were chosen, one supplying 100% outside air to lab spaces and
the other supplying mixed air to office spaces, to test new procedures. A combination
of air balancing and AHU redesign eliminated a lot of the reheat run-time and reduced
the cooling load by 250 tons. In another tune-up measure, Mobil converted the lab
supply units from constant 100% outside air to dual duct design where return air could
be diverted to mix with outside air when possible.
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
Lessons learned: Because the entire cur handling system needed to be overhauled, forming a team
including all potential players proved to be very effective. The AHU upgrades were able to
reduce the cooling load by over 250 tons, and the dual duct design eliminated an additional 40
tons of cooling. As a result, Mobil was able to completely turn off one 250-ton chiller. Mobil
had made an investment on the new CFC-free chillers prior to joining the Showcase program and
conducting file tune-up. The new chillers were sized based on expected ^downsizing from
lighting and other measures, however, the building tune-up led to an additional 290 tons
reduction. By staging upgrades and completing a tune-up prior to committing capital for
equipment, additional cost and energy savings are sometimes possible. '- ' '
Montgomery County, MD
The Montgomery County office building is a seven-story building with one air handling
unit and VAV boxes dedicated on each floor. By breaking down energy consumption
by "end-use it was discovered that a large amount of annual energy was used for heating
(31%). The tune-up process identified electric reheat coils in the VAV boxes that were
operating nearly continuously during summer months. A combination of faulty sensors
and inefficient controls Was causing substantial overcooling in combination with reheat.
To solve the problem, Montgomery County demonstrated new DDC control systems
and schedules to eliminate reheat for most of the cooling season. The demonstration
showed significant savings which if applied to the total building would result in an
annual reduction in heating energy of over 2 million kBtu (53%).
As part of the Showcase upgrades/ Montgomery County initiated the new air supply
schedules on all of the floors. Other measures included air balancing and thermostat
calibration on all floors, and installation of controls on the chilled water valves.
Lessons Learned: Measuring energy consumption by end-use before performing surveys can lead
to identification of significant savings. Few comfort complaints do not necessarily imply an
efficiently running system, especially when reheat is used. Thermostats must be calibrated
regularly, especially if they provide input to the chiller. Example: a sensor in error by two
degrees trying to maintain 65 F will cause the chiller to overwork to cool a space to 63 F (when
the sensor'wouldread 65 F).
The benefit of demonstrating energy efficiency measures on one or more floors was another
valuable lesson. A small investment can show real energy savings, and can justify application of
the measures to tlie remainder of the floors, as well as provide a more accurate estimate of overall
energy savings
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
SHOWCASE ALL-
STAR
Honeywell Inc.
The Honeywell Inc. Showcase facility is located at
Honeywell Plaza in Minneapolis, MN. This project stands
out because of the extensiveness of the upgrades while"
maintaining a highTRR.
Honeywell Plaza houses the corporate offices of
Honeywell, Inc. and consists of three primary facilities
known as Plaza South, Plaza East, and Plaza West. The
gross square footage of this Showcase building complex is
approximately 958,000 square feet The facility's average
annual energy costs, excluding the mainframe computers,
prior to joining the Showcase program was $967,580.
The Plaza has been built in stages and has expanded with
Honeywell's growth through the years. Plaza East consists
of six smaller attached buildings ranging from 4 to 10 floors
each. Plaza West consists of one independent stand-alone
building with eight floors. Plaza South is the latest
building constructed at the Honeywell facility and consists
of one building with five floors. This building houses the
main computer support systems for the overall company
transactions.
Building Control and
Operation
Plaza East
Plaza South
Plaza West
The Honeywell facility is equipped with a Honeywell
energy management system (EMS) known as the DeltaNet
System. This system has a capacity of 20,000 control points.
with about 600 points currently in use. The system
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
Overview of
Lighting and HVAC
Systems
presently controls the operation of the air handling units,
chillers, hot water pumps, chilled water pumps, condenser
water pumps, boilers, and the overall building security
systems. -
The general facuity operational hours are Monday through
Friday from 7:30 AM to 6:00 PM. The lighting and HVAC
operational hours extend before and after the occupancy
hours and are generally from about 5:30 AM to 8:30 PM
with the exception of Mondays when the units are started
at 4:00 AM for pre-warmup. The standard facility
thermostat set point is 72° F on a year-round basis.
Work orders for problems found in the building are
executed based on a schedule developed by a sophisticated
computer program.
A brief description of the Honeywell Plaza lighting and
HVAC systems prior to the tune-up measures is given
below.
Lighting. After Stage 1: Green Lights upgrades, the interior
lighting fixtures for all of the three Plazas consisted of a
variety of fluorescent fixtures with T8 lamps and electronic
ballasts. There were also some incandescent and compact
fluorescent fixtures throughout the facility. Several areas
are equipped with occupancy sensors. '
Air Distribution. Most of the fan systems at the Honeywell
Headquarters are variable air volume (VAV) systems.
Most of the AHUs in the three Plazas are equipped with an
economizer or a pre-heat coil. Fan operations are
controlled by the building EMS. Existing supply and
return fans are automatically turned on and off depending
on their EMS operational set points.
Cooling. The cooling systems consist of large chillers
throughout the various Plazas. Plaza South has four
chillers with a total capacity of 1625 tons, Plaza West has
two 110-ton chillers, and Plaza East uses three chillers with
a total capacity of 1110 tons. In the past, Plaza East
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
utilized well water to directly address the building's
cooling requirements in favorable weather conditions.
However, due to new state restrictions, Honeywell was
required to abolish its use of well water by the end of 1995,
Therefore, the capacity of the chiller plant in the adjacent
Plaza South building will be expanded using thermal cold
water storage to accommodate the cooling load
requirements of Plaza East
Heating. Two large steam boilers, installed in 1947 and
located in the lower level of Plaza East, provide the heating
requirements for all of Honeywell's three Plazas.
Pre-Tune-Up
Modeling
Before implementation of any measures were completed, a
DOE-2 model of Plaza West was performed to simulate
energy consumption before and after upgrades. Building
characteristics were entered, and the model was calibrated
based on utility bills to increase accuracy. The tune up
measures that were included in the simulation were winter
night setback to 60 F (instead of 66 F) and a change in the
minimum setting of the VAV boxes from 10 percent to 30
percent to increase comfort The model estimated the cost
for these measures to be $1,800. As a result, the fan energy
savings would be 39,300 kWh, and the annual cooling
energy would increase by about 500 kWh (since the range
of VAV control between 10% and 30% would now operate
at 30%, consuming slightly more energy). The heating
system would save 2,750 therms annually, and overall
annual savings would be $2,450 (IRR136%).
Building Tune-Up
Measures
The Outside Homes & Buildings division of Honeywell
was used to investigate tune-up measures. Problems were
identified using the Building Tune-Up survey form found
in Appendix B in the Energy Star Buildings Manual. Table
2 is a listing of the major problems and tune-up actions
taken as part of Stage 2 upgrades. It includes the savings
and costs which can be expected for particular measures.
A summary of highlighted measures follows the table.
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
Table 2. Summary of Honeywell Tune-up Measures
lisa&ls-m identified -\ , ; ;
* v^S. -/.. ''"j f ~*"* "f-i "> --v>v» * * "&*
Outdoor lights on South
loading dock operate all day
Space temperature not set
back at night during winter
Vending machines and
water coolers operate
constantly
Heat exchangers and valves
not insulated ,
Leaves in AHU coil
Poor access to dampers in
several AHUs
Leaky AHU dampers
Poor air filtration in several
AHUs -
Coil fins damaged in several
AHUs
Dirty bearings, fan wheels,
and chambers in AHUs
Loose fan belt
Dirty chilled water coil
Broken RA damper motor
Faulty fan starter connection
Tom supply canvas
Worn out outside air .
dampers
Two uninsulated boilers
jy />'-V*V"i V.V.V. > j v,>v.% .S. f
:Ac:ti(pt Mecoieupaelideti.";
,*;/ , v ,--.??v, /< ,-^ ,v~
' \^ '--, : ,*<: ^TOc^» - \
Repair photocell
Program night setback into
EMS
Install time docks on
coolers and vending
machines containing non-
perishable goods such as
soda
Insulate all exposed metal
surfaces on the steam
distribution system
Repair screen
Install access doors
Repair/ adjust dampers
Upgrade primary filters
Straighten fins
Clean AHUs
Tighten belt
Clean coil
Replace motor
Repair starter
Repair canvas
Replace dampers
Insulate boilers
tVtttyttyp -,' f
jB$9t;
:t%f , ;
$150
$500
$3,465
$19,300
$50
$4,000
$1,000
$2,000
$150
$1,100
$20
$50
$200
$200
$100
$1,200
$16,500
:-Jb0d9^aJT''x.j
$aTiegs*-i
$40
$13,200*
$6,000*
$3,800
$100
$2,000
$1,000
$500
$50
$550
$20
$50
$200
$200
$200
$500
$4,500
$Enpie^ !
<«. ""ff » **j :
rFay»a«%/'!
3.8 yr
immediate
0.6 yr
5.0 yr
0.5 yr
2.0 yr
1.0 yr
4.0 yr
3.0 yr
2.0 yr
1.0 yr.
1.0 yr
1.0 yr
1.0 yr
0.5 yr
2.4 yr
3.7 yr
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ENERGY STAR Buildings Tech Tips
Building Tune-Up
Boilers need tune-up
Over 400 defective steam
traps
Some fans running
unnecessarily
Frequent start-up of
secondary chiller
Dirty chilled water coil
Test and tune-up boilers
Repair-replace steam traps
Minimize fan run times
Adjust setpoints in EMS
Clean coil
$1,000
$57,400
$100
$200
$50
$500
$27,600*
$500
$1,000
$50
2.0 yr
2.1 yr
0.2 yr
0.2 yr
1.0 yr
Totals:, $108,785 $62,560 1.7 yr
* Denotes savings which were measured and verified. All others are projected savings based on
modeling
Timers on vending machines. For several hours every night vending machines operate
without anyone using them. The facilities engineers unplugged several machines
during hours when it was expected that they wouldn't be used, and did not receive any
complaints. By monitoring the energy consumption of machines left on during this
period, they were able to determine that they could save $6,000 per year, with a simple
payback of about 7 months, by installing timers. This strategy will work on machines
serving non-perishable items, as well as display cases and other devices used only
during occupied hours.
Replacing steam traps. Ultrasonic testing of the steam traps along the distribution system
identified over 400 defective traps, which were wasting over $27,000 per year in fuel
costs.
Winter night setback. Initially winter night and weekend setback was set at 66 degrees,
which consumed a lot of energy during the particularly cold weather which could be
expected in Minnesota. Significant savings at a small initial cost were achieved by
lowering the space temperature set point to 60 degrees during the winter for night
unoccupied hours.
Lessons Learned: Even though tine Honeywell Plaza buildings were already very well
maintained, before the Showcase -project commenced, the tuned building will save an estimated
$62,560 per year, or 6.5% oftlie total operational costs. The net internal rate of return for the
tune-up measures is about 58%. Using in-house personnel to survey and implement measures
increases the profitability of many measures which otherwise would not have been implemented.
12
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ENERGY STAR Buildings Tech Tips
Building Tune-lip
CONCLUSION
Tune-up measures provide significant savings, usually
with a minimal investment A complete building audit can
usually be performed by in-house personnel, or outside
consultants can be hired if cost-effective. Measures as
simple, as cleaning cooling coils save energy by allowing air
handling systems to operate more efficiently. Other
measures, such as updated EMS controls, provide larger
savings by improving building operations. In many cases,
performing a tune-up before approaching other upgrades
provides a quick payback and savings which can be used to
fund future upgrades. A newer building should expect to
budget $0.01 - $0.10 per square foot for the tune-up. Older
buildings and tune-ups involving significant purchases
should budget $0.10 - $0.50 per square foot
As was found in the Showcase projects, there are other
advantages to tune-up measures besides direct energy
savings. Cooling and heating loads can be reduced when
the building is operating more efficiently. Indoor air
quality problems can be prevented by a regular
maintenance and cleaning schedule of air handling
equipment Correcting faulty sensors and controls reduces
the amount of comfort complaints in a building. Although
quantifying these advantages in terms of costs and savings
is hard to estimate, the functional improvements merit
their consideration.
By following the Energy Star Buildings staged strategy, the
building tune-up should occur prior to investment in
mechanical equipment upgrades and should be one of the
first actions in an upgrade project A good tune-up
procedure should include a full understanding of the
energy profile of a building through an energy end-use
breakdown, a comprehensive facility survey, and an
examination of O&M procedures for improvements.
Training of in-house staff for new equipment, and of new
staff for existing equipment will prevent potential
problems and ensure efficient operation. A comprehensive
tune-up strategy plays a significant role in protecting the
environment by reducing greenhouse gas emissions.,
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