20030207First Response Idaho Power.pdf

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MONICA MOEN ISB #5734
Idaho Power Company
P. O. Box 70
Boise , Idaho 83707
Telephone No. [phone]
FAX Telephone No. [phone]
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Attorney for Idaho Power Company
Street Address for Express Mail:
1221 West Idaho Street
Boise, Idaho 83702
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE
APPLICATION OF IDAHO POWER
COMPANY FOR AUTHORITY TO
IMPLEMENT A RESIDENTIAL AIR
CONDITIONER CYCLING PILOT
PROGRAM.
CASE NO. IPC-02-
IDAHO POWER COMPANY'
RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF
COMES NOW , Idaho Power Company ("Idaho Power" or "the Company
and in response to the First Production Request of the Commission Staff dated
January 24, 2003, herewith submits the following information:
Request No.1: Please provide the results of any research Idaho Power
has done to assess how much premature wear and lost efficiE:mcy are likely to occur as
a result of increased cycling of air conditioners.
Response to Request No.1: Prior to filing its application for the
Residential Air Conditioner Cycling Pilot Program ("Program" or "Pilot Program ) with
the Commission, the Company consulted the purveyors of thermostats and load control
equipment who advised the Company that there was no premature wear of air
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page
conditioners as a result of air conditioner load control cycling. Furthermore, managers
of existing air conditioner cycling programs at other utilities assured the Company that
premature wear and lost efficiency had not been an issue with their programs. Since
filing the Program , the Company has not encountered any research that concludes that
air conditioner cycling within the parameters considered by the Company is harmful to
the efficiency or wear of air conditioners.
The information that Idaho Power has found indicates that air conditioner
cycling within the parameters considered by the Company is within the industry
guidelines set by the Air Conditioning & Refrigeration Institute (ARI). This national trade
association , which represents manufacturers of central air-conditioning equipment
publishes a guideline entitled "Energy Management Systems and Load Management
Through Duty Cycling," ARI Guideline A-1987 , that addresses peak load reduction
through air conditioner cycling. Guideline No., Cycling Rate, indicates that Idaho
Power s plan to cycle air conditioners two to three times an hour is within industry
guidelines. Attached is a copy of ARI Guideline A-1987.
The response to this request was prepared by Kent McCarthy, Planning
Engineer, Idaho Power Company, in consultation with counsel , Monica Moen, Attorney
for Idaho Power Company.
Request No.2: How will this program measure the effect of increased
cycling on efficiency and premature wear on air conditioners?
Response to Request No.2: Since Idaho Power s proposed cycling of
air conditioners is well within industry guidelines , Idaho Power does not anticipate that
there will be any effects on the air conditioners due to load control cycling. Idaho Power
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 2
does not anticipate measuring any effect of increased cycling on the efficiency of and
premature wear on central air conditioners.
The response to this request was prepared by Kent McCarthy, Planning
Engineer, Idaho Power Company, in consultation with counsel, Monica Moen , Attorney
for Idaho Power Company.
Request No.3: Please provide the results of any research Idaho Power
has done to assess how frequently typical residential air conditioners currently cycle
under various conditions.
Response to Request No.3: Idaho Power has not conducted any formal
research to assess how frequently typical residential air conditioners currently cycle
under various conditions. However, the Idaho Public Utilities Commission staff provided
the Company with an article entitled
, "
Energy-Efficiency Air Conditioning," published by
the United States Department of Energy, that does address the issue of air conditioner
sizinq and cycling (page 5, Sizing Air Conditioners). After reviewing this article, the
Company believes that this material addresses frequent cycling due to over sizing of air
conditioners and does not address load reduction cycling. Attached is a copy of this
article (DOE/GO-10099-379, FS 206, June 1999).
Since the Company is planning to cycle air conditioner units only two to
three times per hour, which is within industry guidelines , the Company has deemed it
unnecessary to conduct extensive research to assess the frequency which typical
residential air conditioners cycle under various conditions.
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 3
The response to this request was prepared by Kent McCarthy, Planning
Engineer, Idaho Power Company, in consultation with counsel , Monica Moen, Attorney
for Idaho Power Company.
Request No.4: Idaho Power s Application states the goal of the AC
Cycling Pilot Program is to assess its effectiveness in reducing peak load.
Will Idaho Power assess the total energy used by each participant
in addition to demand?
Please describe in detail how the effectiveness of each of the three
forms of AC Cycling, as defined in the tariff, will be measured.
Will such measurement include the use of a control group whose
air conditioners and/or thermostats are not affected by this program , but whose energy
use and demand is recorded in the same manner (increments) as those whose air
conditioners and lor thermostats are being altered by this program?
If measuring a control group s usage is not contemplated , please
explain why not.
Please list the physical characteristics of landscapes , houses , and
households that will be criteria for customer participation.
Response to Request No.
Yes. The Company will assess the effect of cycling events on
average energy usage. The Company does not plan to assess the change in energy
consumption resulting from the use of programmable thermostats.
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 4
The response to this request was prepared by Paul Werner, Business
Analyst, Idaho Power Company, in consultation with counsel, Monica Moen , Attorney
for Idaho Power Company.
The Company does not propose to test the effectiveness of each of
the three forms of AC Cycling mentioned in the tariff.
AC Cycling was defined broadly in the tariff to include three types of
cycling strategies in order to allow the Company the flexibility to use the capabilities of
whichever load control system is selected and to adjust the cycling strategy during the
pilot program if necessary.
The effectiveness in reducing peak load of the cycling strategy or
strategies that are used in the Pilot Program will be evaluated by comparing the
average load profiles of the participants on cycling days with the average load profiles of
the participants on similar non-cycling days.
The response to this request was prepared by Paul Werner, Business
Analyst, Idaho Power Company, in consultation with counsel , Monica Moen , Attorney
for Idaho Power Company.
No.
The response to this request was prepared by Paul Werner, Business
Analyst, Idaho Power Company, in consultation with counsel, Monica Moen, Attorney
for Idaho Power Company.
The Company believes that the effectiveness of the Pilot Program
in reducing peak load can be evaluated by comparing the demand data of the
participants on cycling days with the demand data of the participants on non-cycling
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 5
days, and accordingly, that the expense of selecting, maintaining, and metering a non-
cycling control group to collect baseline interval demand data can be avoided.
The response to this request was prepared by Paul Werner, Business
Analyst, Idaho Power Company, in consultation with counsel, Monica Moen , Attorney
for Idaho Power Company.
This is a Pilot Program with limited participation. The Company
first goal is to select up to 500 participants in the two years of the Pilot Program who
meet the minimum qualifications outlined in the application , i.e., homeowners in Boise
or Meridian who have central air conditioning. If the number of applicants exceeds the
number of allowable participants , Idaho Power will use selection criteria to select
participants.
At the present time, precise selection criteria have not yet been
determined. The Company may choose to select customers based on residential
location , size of home or other factors aimed at creating a diverse population for this
Pilot Program. The Company will attempt to select participants in as egalitarian a
process as possible. The Company does plan to collect data from applicants regarding
characteristics such as landscaping, housing types and household size to be used for
analysis and Program evaluation. If it is necessary to utilize criteria to select
participants , this information will be useful in creating a diverse group of participants.
The response to this request was prepared by Kent McCarthy, Planning
Engineer, Idaho Power Company, in consultation with counsel , Monica Moen , Attorney
for Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 6
Request No.5: Has Idaho Power assessed the effect that poor air
conditioner design installation and maintenance have on peak demand? Such factors
include, but may not be limited to , oversized AC units, improper charging of the AC unit
lack of cleaning, leaking or improperly sized, imbalanced or otherwise poorly installed
ducts, and inefficient housing envelopes.
If so , please provide the results of such assessments.
If not, please explain why Idaho Power believes controlling AC units
and thermostats is potentially more cost-effective than programs to help correct other air
conditioning inefficiencies?
Response to Request No.5: No.
The response to this request was prepared by Darlene Nemnich , Energy
Efficiency Coordinator, Idaho Power Company, in consultation with counsel, Monica
Moen, Attorney for Idaho Power Company.
N/A.
The response to this request was prepared by Darlene Nemnich , Energy
Efficiency Coordinator, Idaho Power Company, in consultation with counsel , Monica
Moen , Attorney for Idaho Power Company.
Idaho Power does not purport that controlling air conditioning units
and thermostats is more cost effective than programs to help correct other air
conditioning inefficiencies, nor does establishing this Pilot Program preclude the
implementation of programs aimed at addressing air conditioner inefficiencies in the
future. In fact, the two programs could complement one another.
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 7
The Company s goal for the air conditioner cycling Pilot Program is
to test the effectiveness of a dispatchable residential air conditioner load control
program in reducing summer peak demand. The Company s plan is to operate the
Program such that the peak load is reduced in a uniform , dependable and dispatchable
manner. The Company intends to measure the feasibility, practicality and cost-
effectiveness of this type of dispatchable load control program. Current research
indicates that other electricity providers have been successful in their efforts to cycle
residential air conditioners and to reduce peak loads. However, the Company wishes to
assess the feasibility, practicality and cost-effectiveness of this Program as well as the
level of consumer satisfaction given the geographic and climatic characteristics of Idaho
Power s service area.
The response to this request was prepared by Darlene Nemnich, Energy
Efficiency Coordinator, Idaho Power Company, in consultation with counsel , Monica
Moen , Attorney for Idaho Power Company.
Request No.6: Given that temperatures and humidity sometimes are
significantly different between urban and rural locations , please explain why the
Company is proposing to limit this trial to customers who live within the city limits of
Boise and Meridian.
Response to No.6: The Company wants to limit the geographic area for
the Pilot Program to make it economical and logistically easier to manage. Idaho Power
chose the Boise and Meridian areas because (1) offering this program in a limited area
will require fewer trained personnel to administer the program , (2) it is more cost-
effective to install the thermostats and the meters in densely populated areas , (3) a
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 8
smaller geographic area will necessitate contracting and training fewer HV
contractors to install the thermostats and (4) there is enough urban diversity in the Boise
and Meridian areas to test the effectiveness of this Pilot Program in a variety of settings.
The response to this request was prepared by Pete Pengilly, Senior
Analyst, Idaho Power Company, in consultation with counsel , Monica Moen, Attorney
for Idaho Power Company.
Request No.7: Please provide a breakdown of the estimated $820 000
cost of the AC Cycling program, including, but not limited to: costs of meters
thermostats , installation labor, transportation , other hardware and software, labor to
control air conditioners and thermostats , data analysis and program evaluation.
Response to Request No.7: Although Idaho Power has estimated the
costs associated with this Pilot Program , some of the costs requested in Request No.
have not been separately identified (such as the labor to control air conditioners).
Attached is a copy of Idaho Power s Estimated Air Conditioner Cycling Pilot Program
Costs.
The response to this request was prepared by Sandy Kowallis , Business
Analyst, Idaho Power Company, in consultation with counsel, Monica Moen , Attorney
for Idaho Power Company.
Request No.8: The tariff says that customers who volunteer to participate
in the pilot will be able to opt out one day each month by notifying the Company prior to
4 p.m. the day before that customer wants to opt out.
How will the Company handle disputes if a customer claims to have
notified the Company, but the Company has no record of such notification?
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 9
How will the Company handle a situation that is deemed to be an
emergency that was not foreseen by a customer prior to 4 p.m. the day before?
Response to Request No.
The Company does not foresee disputes with customers claiming
to have notified the Company of their interest in opting out of the program. However
the Company intends to keep records of all communications with customers with regard
to the one day opt out provision. In this way, the Company can track the frequency of
such events and track individual customer s opt out record and preferences. The
Company also plans to require customers to complete a very brief opt out questionnaire
to find out why the customer wishes to opt out. This questionnaire will provide another
record of customer activity. Should a dispute arise, the Company will trouble-shoot the
situation to prevent it from reoccurring and work individually with the customer to ensure
his/her satisfaction with the Program.
The response to this request was prepared by Pete Pengilly, Senior
Analyst, Idaho Power Company, in consultation with counsel, Monica Moen , Attorney
for Idaho Power Company.
Based on the information provided by the thermostat purveyors and
the managers of existing air conditioner cycling programs, the Company believes that
household temperatures should not increase by more than two degrees during air
conditioner cycling periods. However, in the rare event that this amount of temperature
fluctuation causes an emergency for a customer, the Company will work with the
customer on a case-by-case basis to reach a mutually satisfactory outcome.
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTION
REQUEST OF COMMISSION STAFF Page 1 0
The response to this request was prepared by Pete Pengilly, Senior
Analyst, Idaho Power Company, in consultation with counsel , Monica Moen , Attorney
for Idaho Power Company.
Request No.9: Will the old thermostats of participating customers be left
with those customers when Idaho Power s programmable thermostat is installed?
If not, when a customer decides to terminate participation in the
program and returns the new thermostat to the Company according to the terms of the
tariff, will the Company then return the old thermostat to that customer?
Will the Company reinstall the old thermostat at no charge?
Response to Request No.9: Yes.
The response to this request was prepared by Pete Pengilly, Senior
Analyst, Idaho Power Company, in consultation with counsel , Monica Moen , Attorney
for Idaho Power Company.
N/A
The response to this request was prepared by Pete Pengilly, Senior
Analyst , Idaho Power Company, in consultation with counsel , Monica Moen , Attorney
for Idaho Power Company.
No.
The response to this request was prepared by Pete Pengilly, Senior
Analyst, Idaho Power Company, in consultation with counsel, Monica Moen, Attorney
for Idaho Power Company.
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTIONREQUEST OF COMMISSION STAFF Page 11
DATED at Boise , Idaho, this 7th day of February, 2003.
MONICA MOEN
Attorney for Idaho Power Company
IDAHO POWER COMPANY'S RESPONSE TO FIRST PRODUCTIONREQUEST OF COMMISSION STAFF Page 12
CERTIFICATE OF SERVICE
I HEREBY CERTIFY that on the 7th day of February, 2003 , I served a true
and correct copy of the within and foregoing IDAHO POWER COMPANY'S RESPONSE
TO FIRST PRODUCTION REQUEST OF THE COMMISSION STAFF upon the
following named parties by the method indicated below, and addressed to the following:
Lisa Nordstrom
Deputy Attorney General
Idaho Public Utilities Commission
472 W. Washington Street
O. Box 83720
Boise, Idaho 83720-0074
Hand Delivered
S. Mail
Overnight Mail
FAX
MONICA MOEN
CERTIFICATE OF SERVICE
TT A CHMENT
RESPONSE NO.
. """-
1987
GUIDELINE for
(REAFFIRMED 1997)
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AIR-CONDITIONING &
REFRIGERATION
INSTITUTE
ENERGY
MANAGEMENT
SYSTEMS AND
LOAD
MANAGEMENT
THROUGH
DUTY
CYCLING
Guideline
4301 NORTH FAIRFAX DRIVE ARLINGTON. VIRGINIA 22203
.. . "
IMPORTANT
SAFETY RECOMMENDA T/ONS
It is strongly recommended that the product be designed, constructed, assembled and instal1ed in accordance
with national1Y recognized safety requirements appropriate for products covered by this guideline.
ARI, as a manufacturers' trade association, uses its best efforts to develop guidelines employing state-of-the-
art and accepted industry practices. However, ARI does not certify or guarantee safety of any products
components or systems designed, tested, rated, instal1ed or operated in accordance with these guidelines or
that any tests conducted under its standards win be non-hazardous or free from risk.
Note:
This is a new guideline.
(Reaffinned 1997)
Price $5,00 (M) $10,00 (NM)
Printed in tLS,
.=:;;
.:-t..,.IQCopyright 1987, by Air-Conditioning and Refrigeration Institute
Re.nstered United States Patent and Trademark Office
~ .
ARI GUIDELINE A-1987
ARI GENERAL GUIDELINES ON ENERGY MANAGEMENT
SYSTEMS AND LOAD MANAGEMENT THROUGH DUTY
CYCLING
ARI recognizes the desire of many customers, users and
other building owners to install some sort of energy
management system (EMS) device on heating, ventilating,
air conditioning and refrigeration equipment. It is also
recognized that some power suppliers feel the need to effect
load management through duty cycling," a program
designed to reduce the peak load on a power distribution
system and hence delay or eliminate the need for additional
generating capacity. ARI offers these guidelines without
stipulating that either energy savings, user comfort or
equipment performance will be achieved.
The product scope of ARl encompasses a wide variety of
products, The availability of various type of EMS devices is
very broad and the effect of such devices on equipment
warranties may vary product-by-product and manufacturer-
to-manufacturer. Therefore, ARl urges that the equipment
manufacturer be contacted for specific recommendations
concerning that equipment.
The general guidelines are as follows:
1. Safety
Do not alter, disable or bypass any of the safety
controls.
2. Control Circuits
Control the unit operation through the control
wiring. An auxiliary power supply may be required
to carry the load of any additional field supplied
controls. Additional load on the equipment
transformer can cause voltage drop, chattering
contactors, and ultimate failure of motor-
compressor or other components.
Fail-Safe Requirement
In the event of failure of an add-on control
device(s), the normal operation of the equipment
being controlled should not be jeopardized.
4. Cycle Rate
Do not short cycle motor controllers, motors, or
motor-compressors. The compressor off cycle must
be five (5) minutes or longer. If more than four (4)
cycles per hour are anticipated, contact the
equipment manufacturer for specific
recommendations.
5. Fossil Fuel Heating Equipment
Do not short cycle or underfire fossil fuel heating
equipment. Adequate burner operating time and
temperature is necessary to prevent condensation
damage to heat exchanger and/or flue.
In the event of any conflict between the manufacturers
specific instructions and these Guidelines, such instructions
should prevail over these Guidelines.
The information in these Guidelines is current as of the date
of publication. These Guidelines are only guidelines and
should not be referred to or construed as a standard
certification or warranty. The appropriate steps to be taken
with respect to duty cycling devices should be done by and
under the supervision of qualified and experienced personnel
to insure proper installation, and should be properly
inspected. However, no changes in these Guidelines (when
identified as ARl guidelines) shall be made without the
approval of ARl.
Released for publication by the ARl General Standards
Committee on June 12, 1985.
Note: Published in the approved ARI Guideline Format in
1987 without change.
TT A CHMENT
RESPONSE NO.
ENERGY
EFFICIENCY
AND
RENEWABLE
DOE/GO-IO099-379
FS 206
June 1999
Energy-Efficient
Air Conditioning
Are you considering buying a new air
conditioner? Or, are you dissatisfied with
the operation of your current air condi-
tioner? Are you unsure whether to fix or
replace it? Are you concerned about high
summer utility bills? If you answered yes
to any of these questions, this publication
can help, With it, you can learn about
various types of air conditioning systems
and how to maintain your air conditioner
hire professional air conditioning services,
select a new air conditioner, and ensure
that your new air conditioner is properly
installed,
Understanding Air Conditioners
Many people buy or use air conditioners
without understanding their designs,
components, and operating principles.
Proper sizing, selection, installation,
maintenance, and correct use are keys to
cost-effective operation and lower overall
costs,
Air Conditioning
'- '- - \,--'
This publication discusses both central
and room air conditioners. Heat pumps,
which provide both home cooling and
heating, are not covered in this publica-
tion, Contact the Energy Efficiency and
Renewable Energy Clearinghouse
(EREC-see Source List below) for more
information about heat pumps of all kinds.
How Air Conditioners Work
Air conditioners employ the same operat-
ing principles and basic components as
your home refrigerator. An air conditioner
cools your home with a cold indoor coil
called the evaporator, The condenser, a hot
outdoor coil, releases the collected heat
outside, The evaporator and condenser
coils are serpentine tubing surrounded by
aluminum fins, This tubing is usually
made of copper. A pump, called the
compressor, moves a heat transfer fluid
(or refrigerant) between the evaporator
and the condenser. The pump forces the
1!.
The fluid that collects heat at the evaporator and releases it at the condenser is called refrigerant.
A pump, called the compressor, forces the refrigerant through the circuit of tubing and fins in
the coils. Air moves through the tiny spaces between the fins and is cooled by the refrigerant in
the coils.
This document was produced for the US Department of Energy (DOE) by the Nadonal Renewable Energy Laboratory (NREL). DOE national laboratory,
The document was produced by the Information Services Program. under the DOE Office of Energy Efficiency and Renewable Energy, The Energy Efficiency
and Renewable Energy Clearinghouse (EREC) is operated by NCllnformation Systems. Inc.. for NREL I DOE. The statements contained herein are based
information known to EREC and NREL at the time of printing No recommendation or endorsement of any product or service is implied if mendoned by EREC,
Printed with a renewable,source ink on paper containing at least 50% wastepaper. including 20% postconsumer waste \.1
refrigerant through the circuit of tubing
and fins in the coils. The liquid refrigerant
evaporates in the indoor evaporator coil,
pulling heat out of indoor air and thereby
cooling the home. The hot refrigerant gas
is pumped outdoors into the condenser
where it reverts back to a liquid giving up
its heat to the air flowing over the
condenser s metal tubing and fins,
Types of Air Conditioners
The basic types of air conditioners are
room air conditioners, split-system central
air conditioners, and packaged central air
conditioners.
Room Air Conditioners
Room air conditioners cool rooms rather
than the entire home, If they provide cool-
ing only where they re needed, room air
conditioners are less expensive to operate
than central units, even though their
efficiency is generally lower than that of
central air conditioners,
Smaller room air conditioners (Le" those
drawing less than 7,5 amps of electricity)
can be plugged into any 15- or 20-amp,
US-volt household circuit that is not
shared with any other major appliances,
Larger room air conditioners (Le" those
drawing more than 7,5 amps) need their
own dedicated US-volt circuit. The
largest models require a dedicated
230-volt circuit.
Condenser fan
Room Air Conditioner
Room air conditioners are installed directly in windows or walls, which means
they have no ductwork. The evaporator s fan faces indoors, while the condenser
fan faces outdoors.
Central Air Conditioners
Central air conditioners circulate cool air
through a system of supply and return
ducts. Supply ducts and registers (Le.,
openings in the walls, floors, or ceilings
covered by grills) carry cooled air from the
air conditioner to the home. This cooled
air becomes warmer as it circulates
through the home; then it flows back
to the central air conditioner through
return ducts and registers. A central air
conditioner is either a split-system unit or
a packaged unit.
In a split-system central air conditioner,
an outdoor metal cabinet contains the
condenser and compressor, and an indoor
cabinet contains the evaporator. In many
split -system air conditioners, this indoor
cabinet also contains a furnace or the
indoor part of a heat pump. The air
conditioner s evaporator coil is installed
in the cabinet or main supply duct of this
furnace or heat pump, If your home
already has a furnace but no air
conditioner, a split-system is the most
economical central air conditioner to install.
In a packaged central air conditioner, the
evaporator, condenser, and compressor
are all located in one cabinet, which
usually is placed on a roof or on a concrete
slab next to the house s foundation. This
type of air conditioner also is used in
small commercial buildings, Air supply
and return ducts come from indoors
through the home s exterior wall or roof to
connect with the packaged air conditioner
which is usually located outdoors. Pack-
aged air conditioners often include electric
heating coils or a natural gas furnace. This
combination of air conditioner and central
heater eliminates the need for a separate
furnace indoors.
Maintaining Existing
Air Conditioners
Older air conditioners may still be able to
offer years of relatively efficient use,
However, making your older air condi-
tioner last requires you to perform proper
operation and maintenance.
:s;
Packaged Air Conditioner
Evaporator
Condenser
A packaged air conditioner sits outside the house next to the foundation or on the
roof. Its cabinet contains the evaporator, condenser, compressor, and all other parts
of the air conditioner. Supply and return ducts connect to this outdoor cabinet.
Evaporative Coolers
An evaporative cooler (also called a "swamp cooler ) is a completely different
type of air conditioner that works well in hot, dry climates,
Evaporative Cooler
1:,
Evaporative coolers cost about half as much as central air conditioners and
use about 25% less energy.
These units cool outdoor air by evaporation and blow it inside the building,
causing a cooling effect much like the process when evaporating perspiration
cools your body on a hot (but not overly humid) day, When operating an
evaporative cooler, windows are opened part way to allow warm indoor air
to escape as it is replaced by cooled air,
Evaporative coolers cost about one-half as much to install as central air condi-
tioners and use about one-quarter as much energy, However, they require
more frequent maintenance than refrigerated air conditioners and they're
suitable only for areas with low humidity,
Air Conditioning Problems
One of the most common air conditioning
problems is improper operation, If your air
conditioner is on, be sure to close your
home s windows and outside doors.
Other common problems with existing air
conditioners result from faulty installation,
poor service procedures, and inadequate
maintenance. Improper installation of your
air conditioner can result in leaky ducts
and low air flow. Many times, the refriger-
ant charge (the amount of refrigerant in the
system) does not match the manufacturer
specifications. If proper refrigerant charging
is not performed during installation, the
performance and efficiency of the unit is
impaired, Service technicians often fail to
find refrigerant charging problems or even
worsen existing problems by adding refrig-
erant to a system that is already full. Air
conditioner manufacturers generally make
rugged, high quality products, If your air
conditioner fails, it is usually for one of the
common reasons listed below:
refrigerant leaks. If your air conditioner
is low on refrigerant, either it was
undercharged at installation, or it leaks,
If it leaks, simply adding refrigerant is
not a solution, A trained technician
should fix any leak, test the repair, and
then charge the system with the correct
amount of refrigerant, Remember that
the performance and efficiency of your
air conditioner is greatest when the
refrigerant charge exactly matches the
manufacturer s specification, and is
neither undercharged nor overcharged,
inadequate maintenance. If you allow
filters and air conditioning coils to
become dirty, the air conditioner will
not work properly, and the compressor
or fans are likely to fail prematurely
electric control failure. The compressor
and fan controls can wear out, especially
when the air conditioner turns on and
off frequently, as is common when a
system is oversized. Because corrosion
of wire and terminals is also a problem
in many systems, electrical connections
and contacts should be checked during
a professional service call.
The most important
maintenance task
that will ensure the
efficiency of your air
conditioner is to
routinely replace
clean its filters.
Regular Maintenance
An air conditioner s filters, coils, and fins
require regular maintenance for the unit to
function effectively and efficiently
throughout its years of service. Neglecting
necessary maintenance ensures a steady
decline in air conditioning performance
while energy use steadily increases,
Air Conditioner Filters
The most important maintenance task that
will ensure the efficiency of your air con-
ditioner is to routinely replace or clean its
filters, Clogged, dirty filters block normal
air flow and reduce a system s efficiency
significantly With nonna1 air flow obstructed,
air that bypasses the filter may carry dirt
directly into the evaporator coil and
impair the coil's heat-absorbing capacity,
Filters are located somewhere along the
return duct's length. Common filter
locations are in walls, ceilings, furnaces, or
in the air conditioner itself.
Some types of filters are reusable; others
must be replaced, They are available in a
variety of types and efficiencies, Clean or
replace your air conditioning system s filter
or filters every month or two during the
cooling season, Filters may need more
frequent attention if the air conditioner is
in constant use, is subjected to dusty
conditions, or you have fur-bearing pets
in the house.
Air Conditioner Coils
The air conditioner s evaporator coil and
condenser coil collect dirt over their
months and years of service, A clean filter
prevents the evaporator coil from soiling
quickly. In time, however, the evaporator
coil will still collect dirt This dirt reduces
air flow and insulates the coil which
Leakage at registers
reduces its ability to absorb heat
Therefore, your evaporator coil should be
checked every year and cleaned as
necessary.
Outdoor condenser coils can also become
very dirty if the outdoor environment is
dusty or if there is foliage nearby. You can
easily see the condenser coil and notice if
dirt is collecting on its fins,
You should minimize dirt and debris near
the condenser unit, Your dryer vents
falling leaves, and lawn mower are all
potential sources of dirt and debris.
Cleaning the area around the coil, removing
any debris, and trimming foliage back at
least 2 feet (0.6 meters) allow for adequate
air flow around the condenser,
Coil Fins
The aluminum fins on evaporator and
condenser coils are easily bent and can
block air flow through the coil. Air
conditioning wholesalers sell a tool called
a "fin comb" that will comb these fins
back into nearly original condition,
Sealing and Insulating Air Ducts
An enormous waste of energy occurs
when cooled air escapes from supply
ducts or when hot attic air leaks into
return ducts. Recent studies indicate that
10% to 30% of the conditioned air in an
average central air conditioning system
escapes from the ducts.
For central air conditioning to be efficient,
ducts must be airtight Hiring a competent
professional service technician to detect
and correct duct leaks is a good investment,
since leaky ducts may be difficult to find
without experience and test equipment.
Duct Leakage at Seams and Registers
'"'
Air from hot attics can leak into the home around registers of the duct system. Air in the ducts
can leak out through holes and seams.
Ducts must be sealed with duct "mastic.
The old standby of duct tape is ineffective
for sealing ducts,
Obstructions can impair the efficiency of a
duct system almost as much as leaks, You
should be careful not to obstruct the flow
of air from supply or return registers with
furniture, drapes, or tightly fitted interior
doors. Dirty filters and clogged evaporator
coils can also be major obstructions to air
flow.
The large temperature difference between
attics and ducts makes heat conduction
through ducts almost as big a problem as
air leakage and obstructions. Ducts in
attics should be insulated heavily in
addition to being made airtight
Using Your Air Conditioner
An air conditioner will cool the air in your home fairly quickly, For economical
operation, turn it on only when your home is occupied, You may consider
installing a programmable thermostat These a11ow you to set the time when
the air conditioner will turn on, such as 30 minutes before you arrive home
from work on a hot day, Contact EREC (see Source List) for the fact sheet
Automatic and Programmable Thennostats, During the day, keep the drapes or
blinds dosed on windows that face east, south, and west. This will help reduce
solar heat gain into your home,
Buying New Air Conditioners
Today s best air conditioners use 30% to 50%
less energy to produce the same amount
of cooling as air conditioners made in the
mid 1970s, Even if your air conditioner is
only 10 years old, you may save 20% to 40%
of your cooling energy costs by replacing
it with a newer, more efficient model.
Sizing Air Conditioners
Air conditioners are rated by the number
of British Thermal Units (Btu) of heat they
can remove per hour. Another common
rating term for air conditioning size is the
ton " which is 12 000 Btu per hour.
How big should your air conditioner be?
The size of an air conditioner depends on:
. how large your home is and how many
windows it has;
. how much shade is on your home
windows, walls, and roof;
. how much insulation is in your home
ceiling and walls;
. how much air leaks into your home
from the outside; and
. how much heat the occupants and
appliances in your home generate.
An air conditioner s efficiency, perfonnance
durability, and initial cost depend on
matching its size to the above factors,
Make sure you buy the correct size of air
conditioner, Two groups-the Air Condi-
tioning Contractors of America (ACCA)
and the American Society of Heating,
Refrigerating, and Air Conditioning
Engineers (ASHRAE)-publish calculation
procedures for sizing central air condition-
ers. Reputable air conditioning contractors
will use one of these procedures, often
performed with the aid of a computer, to
size your new central air conditioner.
Be aware that a large air conditioner will
not provide the best cooling. Buying an
oversized air conditioner penalizes you in
the following ways.
. It costs more to buy a larger air
conditioner than you need.
. The larger-than-necessary air condi-
tioner cycles on and off more frequently,
reducing its efficiency. Frequent cycling
makes indoor temperatures fluctuate
more and results in a less comfortable
environment, Frequent cycling also
inhibits moisture removal. In humid
climates, removing moisture is essential
for acceptable comfort In addition, this
cycling wears out the compressor and
electrical parts more rapidly.
. A larger air conditioner uses more
electricity and creates added demands
on electrical generation and delivery
systems,
Air Conditioner Efficiency
Each air conditioner has an energy-
efficiency rating that lists how many Btu
per hour are removed for each watt of
power it draws, For room air conditioners
this efficiency rating is the Energy
Efficiency Ratio, or EER. For central air
conditioners, it is the Seasonal Energy
Efficiency Ratio, or SEER. These ratings
are posted on an Energy Guide Label
which must be conspicuously attached to
all new air conditioners. Many air condi-
tioner manufacturers are participants in
The higher
initial cost of an
energy-efficient
model will be repaid
to you several times
during its life span.
the voluntary EnergyStarCID labeling
program (see Source List in this publication),
EnergyStar-labeled appliances mean that
they have high EER and SEER ratings,
In general, new air conditioners with
higher EERs or SEERs sport higher price
tags, However, the higher initial cost of an
energy-efficient model will be repaid to
you several times during its life span,
Your utility company may encourage the
purchase of a more efficient air conditioner
by rebating some or all of the price
difference, Buy the most efficient air
conditioner you can afford, especially if
you use (or think you will use) an air
conditioner frequently ancVor if your
electricity rates are high,
Room Air Conditioners-EER
Room air conditioners generally range
from 5,500 Btu per hour to 14 000 Btu per
hour. National appliance standards
require room air conditioners built after
january 1,1990, to have an EER of8,0 or
greater, Select a room air conditioner with
an EER of at least 9.0 if you live in a mild
climate. If you live in a hot climate, select
one with an EER over 10.
The Association of Home Appliance
Manufacturers reports that the average
EER of room air conditioners rose 47%
from 1972 to 1991. If you own a 1970s-
vintage room air conditioner with an
EER of 5 and you replace it with a new
one with an EER of 10, you will cut your
air conditioning energy costs in half.
Central Air Conditioners-SEER
National minimum standards for central
air conditioners require a SEER of9.7 and
10,, for single-package and split-systems,
respectively, But you do not need to settle
for the minimum standard-there is a wide
selection of units with SEERs reaching
nearly 17.
Before 1979, the SEERs of central air con-
ditioners ranged from 4,5 to 8.0, Replacing
a 1970s-era central air conditioner with
a SEER of 6 with a new unit having a
SEER of 12 will cut your air conditioning
costs in half
Hiring Professional Service
When your air conditioner needs more
than the regular maintenance described
previously, hire a professional service
technician, A well-trained technician will
find and fix problems in your air condi-
tioning system. However, not all service
technicians are competent. Incompetent
service technicians forsake proper
diagnosis and perform only minimal stop-
gap measures, Insist that the technician:
. check for correct amount of refrigerant;
. test for refrigerant leaks using a leak
detector;
. capture any refrigerant that must be
evacuated from the system, instead of
illegally releasing it to the atmosphere;
. check for and seal duct leakage in
central systems;
. measure air flow through the evaporator
coil;
. verify the correct electric control
sequence and make sure that the heating
system and cooling system cannot
operate simultaneously;
. inspect electric terminals, clean and
tighten connections, and apply a non-
conductive coating if necessary;
. oil motors and check belts for tightness
and wear; and
. check the accuracy of the thermostat.
Choosing a Contractor
Choosing a contractor may be the most
important and difficult task in buying a
new central air conditioning system, Ask
prospective contractors for recent references.
If you are replacing your central air
conditioner, tell your contractor what you
liked and did not like about the old
system, If the system failed, ask the
contractor to find out why. The best time
to fix existing problems is when a new
system is being installed.
When designing your new air conditioning
system, the contractor you choose should:
. use a computer program or written
calculation procedure to size the air
conditioner;
. provide a written contract listing the
main points of your installation that
includes the results of the cooling load
calculation;
. give you a written warranty on equip-
ment and workmanship; and
. allow you to hold the final payment
until you are satisfied with the new
system.
Avoid making your decision solely on
the basis of price, The quality of the
installation should be your highest
priority, because quality will determine
energy cost, comfort. and durability
Installation and Location of
Air Conditioners
If your air conditioner is installed
correctly, or if major installation problems
are found and fixed , it will perform
efficiently for years with only minor
routine maintenance, However, many
air conditioners are not installed correctly.
As an unfortunate result, modern energy-
efficient air conditioners can perform
almost as poorly as older inefficient models.
Be sure that your contractor performs the
following procedures when installing a
new central air conditioning system:
. allows adequate indoor space for the
installation, maintenance, and repair of
the new system, and installs an access
door in the furnace or duct to provide a
way to clean the evaporator coiL
. uses a duct-sizing methodology such as
the Air Conditioning Contractors of
America (ACCA) Manual
. ensures there are enough supply
registers to deliver cool air and enough
return air registers to carry warm house
air back to the air conditioner.
. installs duct work within the conditioned
space, not in the attic, wherever possible.
. seals all ducts with duct mastic and
heavily insulates attic ducts,
. locates the condensing unit where its
noise will not keep you or your
neighbors awake at night, if possible,
. places the condensing unit in a shady
spot, if possible, which can reduce your
air conditioning costs by 1 % to 2%.
. verifies that the newly installed air
conditioner has the exact refrigerant
charge and air flow rate specified by the
manufacturer.
. locates the thermostat away from heat
sources, such as windows, or supply
registers.
All ducts should be insulated when they are
located in attics or crawl spaces.
Sealing Ducts
c::::d
Reputable contractors seal alljoints in both
new and existing ducts with duct mastic.
If you are replacing an older or failed split
system, be sure that the evaporator coil is
replaced with a new one that exactly
matches the condenser coil in the new
condensing unit (The air conditioner
efficiency will likely not improve if the
existing evaporator coil is left in place;
in fact, the old coil could cause the new
compressor to fail prematurely)
If you install a new room air conditioner
try to:
. locate the air conditioner in a window
or wall area near the center of the room
and on the shadiest side of the house.
. minimize air leakage by fitting the room
air conditioner snugly into its opening
and sealing gaps with a foam weather
stripping material.
Paying attention to your air conditioning
system saves you money and reduces
environmental pollution, Notice whether
your existing system is running properly,
and maintain it regularly Or, if you need
to purchase a new air conditioner, be sure
it is sized and installed correctly and has a
good EER or SEER rating.
TT A CHMENT
RESPONSE NO.
Idaho Power Company
Estimated Costs
Air Conditioner Cycling Pilot Program
Year 2003 2004
Number of Participants 200 300
Thermostat Cost/Unit $195 $195
Installation Cost/Unit $50 $50
Thermostat Cost (2 x (3 + 4))$49,000 $73,500
6 Palm Pilots (Thermostat Data Recorders)380
7 System Implementation & Training $19 000
8 System Hosting $6,000 000
9 Software Fees 250 700
Communications Costs $5,300 800
Control System Cost (Sum 6 : 10)$33,930 $16,500
Interval Meters Cost/Meter $187 $187
Interval Meter Installation Cost/Meter
Metering Cost (2 x (12 + 13)$38,716 $58,074
Management/Data Analysis/Evaluation/Recruitment $115,000 $115,000
Promotion $100 000 $100 000
Ongoing Maintenance $50 000 $50 000
Customer Incentives 000 500
General Programs Costs (Sum 15: 18)$268,000 $272 500
Total Cost per Year (5 + 11 + 14 + 19)$389,646 $420,574
Total Cost for two Years (20B + 20C)$810,220
Idaho Power Company
Case No, IPC-O2-