Home Heating and Cooling

Reduce your utility bills with low-cost, low-tech tips

Get more heat from every energy dollar you spend—page 3

Make the most of your air-conditioning system—page 10

Landscape your yard for year-round comfort—page 19

Home Series

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Home Heating

and Cooling

Every year, a typical family in the United States spends around half of its home

energy budget on heating and cooling. In Iowa, that percentage can be higher, due

to temperature extremes reached during the winter and summer months.

Unfortunately, many of those dollars oen are wasted, because conditioned air

escapes through leaky ceilings, walls and foundations—or flows through

inadequately insulated attics, exterior walls and basements. In addition, many

heating systems and air conditioners aren’t properly maintained or are more than

10 years old and very inecient, compared to models being sold today.

As a result, it makes sense to analyze your home as a collection of systems that

must work together in order to achieve peak energy savings. For example, you won’t

get anywhere near the savings you’re expecting from a new furnace if your air-

handling ducts are uninsulated and leak at every joint. e most energy-ecient

central air-conditioning setup won’t perform to your expectations if your attic

insulation is inadequate and can’t reduce solar heat gain to help keep your home

cool. And planting the wrong types of trees or shrubs close to your home adversely

can aect potential energy savings all year long.

Across the country, heating and cooling an

average home consumes almost as much

power as all other energy uses combined.

The “Other” category includes a variety of

household products such as stoves, ovens,

microwaves and small appliances.

Source: ENERGY STAR®

Energy use in a typical home

Here’s the bottom line

By properly maintaining your existing heating and cooling equipment (or replacing aging

units with high-eciency models), addressing weatherization and insulation issues at your

house and getting into the habit of using energy eciently all the time, you can save 10 to 30

percent (or more) on your utility bills every year. You’ll also help reduce pollution at utility

plants that use fossil fuels to generate electricity. (According to the U.S. Department of Energy,

the electricity generated by fossil fuels for a single home creates more carbon dioxide than

two average-sized cars.)

How much of the work can you do?

If you’re a competent do-it-yourselfer, you can handle many of the maintenance chores and

energy-saving projects described in this book. However, if you’re uncomfortable with the idea

of working around electricity or would rather hire someone to handle a job, don’t hesitate to

call a professional; the dollars saved through energy savings in future years will be worth the

expense. (Of course, only a trained technician should handle jobs that require working with

refrigerants or control units.) For details on hiring a heating and cooling contractor, see page 23.

Your utility or bank might be able to help with project costs

Small energy-eciency projects such as sealing air leaks or weather-stripping windows are

relatively inexpensive. However, when it’s time to purchase a new heating and cooling system,

it makes sense to talk with your utility company and bank before buying. Some utility

companies, for example, oer rebates on high-eciency air-source heat pumps, geothermal

heat pumps, gas furnaces, boilers and central air-conditioning systems.

Ask a banker about a low-interest loan to cover the cost of your energy-saving projects,

or consider a home-improvement loan. If you’re planning to renance your home mortgage,

look for an energy-efﬁciency mortgage that allows a lender to use a higher-than-normal

debt-to-income ratio to qualify you for the loan.

Finally, check for government-sponsored assistance and grant programs designed for

low-income and elderly homeowners. Get in touch with a Community Action Agency in your

area, or see page 24 for information on contacting the Iowa Department of Human Rights/

Division of Community Action Agencies.

Save with a whole-house approach

Heating and cooling

49%

Dishwasher

Refrigerator

Water

heater

13%

Other

Lighting

10%

Electronics

Clothes washer

and dryer

Overview

Did you know?

The Energy Independence and

Security Act of 2007 sets the

stage for significant changes in

energy policy across the United

States for many years to come.

During the next several years, new

energy-efficiency standards will

be put into place for appliances,

furnace motors, residential boilers

and other energy-using devices. So,

watch for the latest news about tax

credits for homeowners who make

energy-saving improvements to their

homes at the Web site of the Tax

Incentives Assistance Project (TIAP) at

http://www.energytaxincentives.org/.

iowa energy center

Heating

Lower energy consumption means lower costs

No matter what kind of equipment heats your home, one thing is certain: e more energy-

ecient the heating system is, the lower your utility bills will be. Using less energy also is good

for the environment, because doing so reduces air pollution and helps conserve natural

resources. In fact, according to the U.S. Department of Energy, the combination of a tight,

well-insulated home, a properly maintained, high-eciency heating system and reasonable

thermostat settings can cut both your heating bill and your pollution output in half.

Is it time for a change?

If you’ve lived in your home for several years—and the heating system was in place when you

bought the house—it may be hard for you to determine if you’ve gotten your money’s worth

out of your current equipment. But consider this: ENERGY STAR® recommends replacing a

furnace or boiler that’s more than 15 years old (or a heat pump or air conditioner that’s more

than 12 years old) with a new, high-eciency unit.

Here are some other clues that it’s time to go shopping for a new heating system:

Your heating bills are going up because the system is using more energy than in past years.

e equipment needs to be repaired frequently—oen for a dierent reason each time.

Some of the rooms in your house are too hot or too cold, no matter how you adjust the

airow through the ducts.

e system just doesn’t seem to be working properly, even aer a recent service call.

e air in your home is exceptionally dry during the heating months.

Unfortunately, you oen can’t see what causes a heating system to waste energy. Beyond

obvious clues such as a sagging duct that blows heated air into the basement, a noisy fan motor

on a forced-air furnace or a leaking fuel line on a boiler, most of the energy-wasting problems

will be hidden from view.

Make a responsible, long-term choice

Even if you decide to replace your heating system with one of the same type, buy the most

energy-efficient unit your budget allows. Although you’ll spend a little more money up

front, you’ll be many dollars ahead in the long run because lower utility bills will shorten the

new equipment’s payback period.

On the other hand, now may be the perfect time to signicantly reduce your family’s

reliance on conventional energy sources by installing a more ecient heating (and cooling)

system. For example, a geothermal heat pump (sometimes referred to as a “ground-

source” heat pump) can give you up to four dollars of heating (or cooling) for every electrical

energy dollar spent. As an alternative, a passive solar sunspace can reduce annual heating

costs by up to 50 percent (compared to a similar house without passive solar heat), as well as

allowing you to install a smaller conventional heating system as a backup for overcast days.

You can have a major impact on reducing heating costs at home

If the time isn’t right to replace your heating system, there are a couple of things you can do to

keep your home warm and comfortable at an aordable cost with the existing equipment. First,

reduce the heating load on your home by eliminating air leaks, adding insulation and

promoting a change in your family’s energy-wasting habits. Second, call a professional heating

and cooling contractor to tune up and optimize the heating system, including an update

of its controls and other internal parts—and adding a programmable thermostat.

In the sections that follow, you’ll nd many proven low-cost, low-tech methods for saving

energy (and money) on your heating needs, in addition to nding out what to consider when

upgrading a heating system and maintaining your heating equipment.

Heating fuels

Although there are several different

types of fuel available for heating,

today more than half of the homes

across the country use natural gas.

Source:

U.S. Department of Energy Oce of Energy

Eciency and Renewable Energy

Natural gas

53%

Electricity

29%

Fuel oil

Other

Heating

Did You Know?

On the ENERGY STAR Web site at

http://www.energystar.gov, you’ll

find a lot of valuable information

in the Home Improvement section.

The Home Energy Yardstick,

for example, takes about five

minutes to ﬁll out and will help you

discover whether your energy use

is above average. The Remodeling

Guide gives you a list of custom-

ized energy improvements (with

estimated savings) for different

areas of your house. And the

Home Sealing section offers

tips on tightening your home’s

“envelope” to lower energy bills.

Did you know?

Heating

System

iowa energy center

Make your heating dollars work harder for you

No matter what type of heating system you have, there are some things you can do to save

energy and still stay comfortable at home during the cold-weather months. Besides calling

a professional to check your heating system, try several of the tips in this section to reduce your

home’s energy usage. Some of these ideas won’t cost you a penny—such as opening the curtains

on south-facing windows to harvest the sun’s warmth during daylight hours—and some may

cost a few dollars that you’ll recoup within a year through reduced energy bills—such as

installing a programmable thermostat. However, they’re all worth considering.

From a whole-house perspective, first look for leaks that allow cold air into your

home—and heated air out. en evaluate the insulation levels in your home and add insulation

where necessary; attic insulation likely will have the most immediate impact on energy savings,

but don’t overlook areas such as the foundation, unnished basement walls and oors above

unheated spaces. For more information on improving your home’s energy-saving “envelope,”

ask your utility or the Iowa Energy Center for the book, Home Series 1: Home Tightening,

Insulation and Ventilation. (See contact list on page 24.)

Survey your home to save

Heating

Let sun shine through

south-facing windows

Repair and install

storm windows

Repair or replace

leaky windows

Install a progammable

thermostat

Set thermostat at

70° F. or lower

Lower thermostat at

night or when gone

Set ceiling fans for

proper circulation

Vacuum baseboard

heaters, air registers

or radiators

Don’t block heat

sources with

furniture

Isolate unused rooms

Close chimney damper

Make sure attic is

adequately ventilated

Trim trees and

bushes to maximize

solar gain

Change furnace

ﬁlters regularly

Have a pro tune up

your heating system

Seal leaks

in ducts

Vent dryer

outdoors

iowa energy center

Follow these tips to stay warm

A plan for saving energy during cold weather includes analyzing all the elements that go into

heating a home—including the habits of the people who live there. So, in addition to making

sure your existing heating system is in peak operating condition (or replacing it with a more

energy-ecient unit), talk with family members about how a little eort can yield signicant

results in cutting heating bills—without adversely aecting anyone's comfort.

Living areas

Walk around your home with this list to discover how many opportunities you have to reduce

energy use during the winter. Most of these ideas won't cost anything more than a few minutes

of time; the tips that do require a small outlay of cash quickly should pay for themselves through

smaller heating bills.

Did You Know?

Adequate attic ventilation is

important during the winter. If air

leaks to the attic from the living

spaces below aren’t adequately

sealed, moisture-laden warm air

can ﬂow to the attic and freeze in

your attic insulation, on the rafters

and on the underside of the roof.

When the temperature gets above

freezing, the ice can melt and run

down to your ceilings and walls,

damaging them. If moisture buildup

in your attic is a problem, check to

make sure all existing attic vents

are not blocked. If they appear to

be okay, look for (and seal) air leaks

and consider installing additional

attic vents.

Did you know?

Set the direction of

ceiling fans for proper

circulation.

Run ceiling fans in a clockwise direction during cold-weather months to

move the warm air that gathers near ceilings back into the rooms.

Warm up your bed.

Turn down your thermostat and use extra blankets or quilts—or an

electric blanket or mattress pad—to stay toasty at night.

Vacuum baseboard

heaters, air registers

or radiators.

When you see dust, dirt and lint building up, clean any of these devices

that are part of your home’s heating system.

Move furniture or

window coverings that

are blocking air registers,

baseboard heaters or

radiators.

Make sure all the heated air you’re paying for reaches its destination!

A blocked air register can cause an adjoining room to overheat,

and upholstery or curtains can trap heat between the wall and the

fabric—preventing it from being distributed throughout a room.

Install radiator reﬂectors. These panels will help reﬂect heat away from walls and into rooms.

Isolate unused rooms, as

long as doing so will not

hurt water pipes.

Turn down the thermostat in a room with baseboard heat,

or close the registers for a forced-air furnace. However, don’t

allow temperatures in rooms with water pipes to approach

the freezing point.

Remove wall or window

air conditioners during

cold-weather months.

For a wall unit, cover the opening with a thick plywood panel

backed by rigid foam insulation; caulk to ensure the unit is

weather-tight. For a window unit, remove it, close the window

and ﬁx air leaks. If you can’t remove the air conditioner, wrap it in

an insulated, waterproof cover made for the job.

Remove humidity from

the kitchen and bathroom

with a properly sized

exhaust fan.

Too much humidity can cause condensation and frost on windows

and possibly damage them. But don’t leave an exhaust fan on

longer—or at a higher speed—than necessary. In one hour, an

exhaust fan can blow a “houseful” of heated air outside. In addition

make sure these fans are not discharging air and moisture into the

attic; they should be vented outdoors.

Heating

Ceiling fan evens

temperatures

To help eliminate the chilly feeling

caused by temperature layering in

a room, run your ceiling fan—on

the lowest speed, in a clockwise

direction—all winter long.

iowa energy center

Buying a new heating system

A new heating system is one of the largest investments you’ll make in your home, and it’s one

of the few that actually could pay for itself over a period of several years. Accordingly, it’s worth

your time to research all the possibilities and “run the numbers” to determine what equipment

makes the most sense for your situation.

Ask a pro for help

Talk with several heating and cooling contractors about choosing a system and handling

the installation for you. (See page 23 for tips on nding a heating and cooling contractor.)

In some cases, you may be limited by the choices available to you. For example, if you live

in an older two-story home that already has radiators in place, it could be very dicult and

expensive to install a new duct system for a forced-air furnace instead of a new boiler. However,

if you’re thinking about making a change—perhaps from a gas forced-air furnace to an air-to-

air heat pump or a geothermal heat pump—be sure to ask the contractors to run cost

comparisons for the fuels and energy sources available in your area. is is a somewhat

complicated process, but there are formulas that make these comparisons possible.

In addition, make sure the contractor properly sizes the new heating equipment for your

home, using a computer program or calculations based on the Air Conditioning Contractors

of America Manual J. is is especially important if you’ve made recent energy-saving im-

provements such as sealing air leaks or adding insulation, which may allow you to choose a

smaller unit than you presently own. An oversized system (the installation of which was a

common practice in poorly weatherized and insulated homes for many years) will cost more

initially—and then will waste heating dollars by running in short, inecient cycles that won’t

be able to evenly heat all the rooms in your house.

en consider the cost to purchase and the cost to operate. For example, compare a

new, super-ecient forced-air furnace that costs $1,200 installed with a no-frills, low-eciency

furnace that costs $750 installed. Because of its reduced energy usage—and the resulting lower

utility bills—the annual operating expense for the more ecient unit might be $400, while the

basic unit might run $550. e dierence in initial cost, $450, would be paid back during just

three years by choosing the more ecient system—and, of course, the savings would continue

to accrue for many years to come. Also ask the contractor for projected repair and

maintenance expenses to factor into your decision-making process.

ere really are dierences among systems

Buy the most energy-ecient system you can aord, even if you have to stretch the budget a

little. Here are some things to consider when evaluating each type of heating system.

Forced-air furnaces

According to ENERGY STAR, about 25 percent of the furnaces in use today are more than 20

years old. Many of these units had eciencies ranging from 56 to 70 percent, compared to the

best systems today that are up to 97 percent ecient. By making energy-saving improvements

in your home and upgrading from a 56-percent-ecient furnace to a 90-percent-ecient one,

every year you’ll cut heating bills by as much as one-half—and reduce carbon dioxide

emissions by 1.5 tons if you heat with gas and 2.5 tons if you heat with oil.

Look for an AFUE rating over 90 for all types of forced-air furnaces. Gas- and oil-red

units at this level include electronic ignition instead of a continuous pilot light, as well as a

sealed combustion chamber that brings fresh outside air to the burner through one pipe and

vents exhaust gases outside through another.

Read the label

The EnergyGuide label on heating

equipment is a summary of the

detailed energy-efﬁciency information

manufacturers are required to furnish

with their equipment. Compare labels

on different units when you shop;

higher efﬁciency numbers indicate

lower energy usage and operating

costs. Look for the ENERGY STAR logo,

too, which means the equipment

exceeds federal minimum efﬁciency

standards and uses signiﬁcantly less

energy than a standard unit.

90.0

Did You Know?

Furnaces and boilers fueled by

natural gas, propane or oil are rated

by AFUE (Annual Fuel Utilization

Efﬁciency). For heating, air-to-air

heat pumps are rated by HSPF

(Heating Seasonal Performance

Factor) and geothermal heat pumps

are rated by COP (Coefﬁcient of

Performance).

Use these numbers to compare

units of the same type; in all

cases, higher numbers are better.

Check with your utility company for

recommended minimum ratings,

and buy the most efficient unit

your budget will allow.

Did you know?

Heating

iowa energy center

Electric resistance

Besides forced-air furnaces, electric resistance heating takes many forms, such as baseboard

heaters, cove units or radiant ceiling and oor systems. e energy advantage of these systems

is that they allow individual room temperature control, allowing low temperatures in seldom-

used rooms and “normal” temperatures in frequently used rooms. In addition, some people

prefer non-forced-air options—especially in bathrooms—because they don’t create dras. For

baseboard heaters, choose liquid-lled units that quietly and evenly release heat over a long

time period. To save money, ask your utility about special rates for electric heating.

Boilers

Shop for a boiler that features the latest technologies for extracting the most heat from a

specied amount of fuel, in addition to including electronic ignition and sealed combustion.

If you need to replace radiators or baseboard units, pick ones designed to most eectively heat

the space. For new construction or a remodeling project, consider a radiant oor system.

Air-source heat pumps

This system gets its name from the way it uses the difference between the outdoor air

temperature and the indoor air temperature to heat (or cool) a home. During the summer, the

air-source heat pump functions as an air conditioner; during the winter, it runs in reverse to

provide heat. Properly installed and connected to a well-designed (and tight) duct system, an

air-source heat pump can deliver up to three units of heating (or cooling) energy for every unit

of electric energy it consumes—except in very cold weather, when a backup resistance heating

system must supplement the heat pump’s output.

Because it heats and cools, an air-source heat pump is a good choice for replacing an

existing heating and cooling system or when you need a new furnace and want to add central

air-conditioning. Look for a heat pump with a high HSPF and SEER rating. e best units have

a two-stage compressor that runs in a low-power, energy-saving mode most of the time, along

with a variable speed blower motor that minimizes noise and energy consumption.

Geothermal (ground source) heat pumps

A geothermal heat pump is the most ecient heating and cooling system available, because it

returns up to four dollars of heating (or cooling) energy for one dollar of electricity consumed.

A geothermal heat pump doesn’t burn fuel to create heat; instead, it uses electricity to move

heat from the ground through a large loop of buried, uid-lled pipes to a compressor located

inside the home.

For a forced-air system, the compressor “concentrates” (or “amplies”) the heat, before it

is distributed throughout the home by a blower motor feeding a conventional duct system.

Another heat pump option uses a “water-to-water” heat exchanger to transfer the warmth from

the uid to an in-oor radiant heating system or baseboard units.

e greatest drawback to a geothermal heat pump is its high installation cost, which can

be several thousand dollars more than the cost of a forced-air furnace/central air-conditioning

system. However, depending on local electricity costs, the payback period can be just a few

years—but certainly will be much shorter than the heat pump’s anticipated lifetime of 20 years

or more. In addition, some utilities oer rebates on installation costs and special electric rates

for geothermal heat pump users—and maintenance costs are low.

For the greatest eciency, look for a geothermal heat pump with a two-stage compressor

and a variable-speed blower.

What’s the scoop on the loops?

The most common types of loops for

geothermal heat pump systems fall

into three categories: a horizontal

loop (top), a vertical loop (center)

and a pond loop (bottom). Some

loops are “closed,” meaning they

circulate a fluid through a sealed

loop underground; others are “open”

and circulate well or ground water

directly through the heat pump

unit. In addition, many systems use

coiled “slinky” pipes buried in the

ground (similar to the ones shown

in the pond illustration) instead of

straight pipes, which concentrates

the heat transfer surface into a smaller

space; this is especially useful for

installations in smaller yards.

Heating

Horizontal loop

Vertical loop

Pond loop

iowa energy center

Caution!

Always turn off the power to your

heating system at the shutoff

located next to the unit or the

circuit-breaker panel (or fuse box)

before performing any cleaning or

maintenance tasks.

CAUTION!

Did You Know?

You can buy a hygrometer to

measure your home’s humidity for

as little as $10-$20; more expensive

units are a little more accurate and

allow you to check (and reset)

their calibration. You also can

watch for condensation on the

windows; good-quality windows

that are properly installed and

weather-stripped should not show

excessive condensation buildup at

a 35 percent humidity level.

Did you know?

Maintenance/Humidification

Maintenance

Regular tune-ups are important for maintaining the eciency of any type of home heating

system. You can handle a few simple tasks yourself if you’re mechanically inclined, but you

should call a professional technician for anything but the simplest service or repairs.

For example, a forced-air furnace or heat pump will run longer than necessary to warm

your home if it has to ght to push air through a dirty air lter; regularly changing the furnace

or heat-pump lter is a job you easily can manage. In addition, if you feel comfortable working

on the system (with the power turned o), you can handle jobs such as vacuuming the blower,

adjusting the blower belt, oiling the blower motor and ushing the condensation drain tube.

However, for a gas furnace, make sure you call a professional to adjust the burner.

If you have a hydronic (boiler) system, you can bleed the radiators or check the water level

in the sight glass on the boiler—but call a technician for other jobs.

Many heating and cooling companies oer discounted maintenance specials every fall, but

make sure you know what’s included in a checkup before hiring a company to do the work on

your heating system. You may have to pay a little more than the special price to get a complete

system evaluation and tune-up, but you’ll likely recoup the higher service cost within a few

months from lower utility bills.

Humidification

Humidity levels are lowest during cold-weather months, and the humidity in your home will

be even lower if your home has an inecient gas-forced-air furnace, all-electric heat or a system

that uses outside air for combustion. When room air is very dry, moisture evaporates from your

skin—just as if you were perspiring—making you feel chilly. Your natural inclination may be

to raise the thermostat a couple of degrees, but a better, energy-saving solution might be to add

a humidiﬁer to your home’s heating system.

To humidify or not to humidify, that is the question

e proper humidity level—many experts suggest around 35 percent—is a good thing for both

you and your house during the winter. Besides allowing you to lower your thermostat setting

two or three degrees because you’ll feel warmer at higher humidity levels, a humidier will

minimize shocks from static electricity and reduce dry-skin and respiratory problems for your

family. In addition, a little extra humidity will help prevent hardwood oors from shrinking,

doors from sticking and furniture from drying out. On the other hand, too much humidity

can create a breeding ground for mold, mildew and insects—and damage the drywall (or

plaster), the insulation and the structure of your home.

Not all homes need additional humidity during the winter. For example, in a tightly

constructed home built during the last several years, normal daily activities such as cooking,

bathing, doing laundry and even breathing may provide adequate humidity levels. In fact,

because of the low level of air inltration in a newer home, some of these activities may add too

much humidity, so be sure to use the kitchen exhaust fan when cooking and the bathroom fan

during a shower. (Run the bathroom fan about 15 minutes aer a shower to remove the

humidity; running it longer will just pull heated air out of your home.) If you still note high

humidity during cold-weather months, consider adding a heat recovery ventilator to your

heating system. (See page 22 for more details on this option.)

Older, drafty homes need more help with humidity than newer homes. You may want

to try a couple of portable humidiers to place around your home, but a better choice (if you

have forced-air heat) is to install a whole-house humidier that attaches to the ductwork on your

heating system. For a home with baseboard heat, radiant heat or radiators, look for a self-

contained humidier that hangs from the oor joists in the basement (or a heated crawl space)

and connects to a oor vent mounted near the center of the home.

iowa energy center

Use simple physics to

warm your home

Heat naturally moves from warmer

materials to cooler ones through

radiation, convection and conduction.

During cold weather, sunlight enters

this home and strikes a thermal mass

that collects and stores the sun’s

heat energy. At night—as the home

cools—the heat is released from the

thermal mass into the home. The next

morning, the cycle starts again.

Here’s how a passive solar

sunspace works

(Top) In this example, the low winter

sun heats a sunspace and convection

carries the heat from this area to

adjoining rooms. (Bottom) During

the summer, large roof overhangs

and window shades inside keep the

high sun from entering the house,

while natural ventilation helps cool

the home and prevents overheating

in the sunspace.

Summer

Winter

Passive solar energy

Passive Solar Energy

During daylight hours in winter, every time you let the sun shine into your home through

south-facing windows, you’re taking advantage of passive solar energy to help warm a room or

two. On a larger scale, a well-designed passive solar home can cost about half as much to heat

as a similarly sized home without solar features. But even if you’re not planning to build a new

home, there are some features you can add during a remodeling project to incorporate the

energy-saving and environmental benets of passive solar energy into your existing home.

A passive solar structure includes ﬁve elements

Taking advantage of passive solar techniques doesn’t have to cost more than traditional con-

struction. Consider, instead, that a passive solar structure includes a dierent arrangement of

many of the same building materials you’d use in a conventional home.

e aperture is the large window area through which sunlight enters a home. e majority

of windows should face within 30 degrees of true south and remain unshaded from 9 a.m.

to 3 p.m. during the heating season.

e absorber is a dark surface—on a concrete oor, masonry wall or water container—that

sits in the direct path of sunlight and collects the sun’s heat.

e thermal mass is the material that stores the heat collected by the absorber. e ab-sorber

and thermal mass may be part of the same oor or wall; the absorber is the surface of the

material, while the thermal mass is the storage medium under or behind it.

e distribution method is the way the solar heat circulates from the thermal mass to other

areas of the house. Some designs rely on natural heat transfer—radiation, convection and

conduction—while other designs use supplemental fans, blowers and/or duct systems.

e control system includes components that help manage temperatures. Some of these

features may be structural, such as roof overhangs or blinds to shade the aperture during

summer. Others are more high-tech, and could include electronic sensing devices that signal

fans to start, as well as remote-control motorized dampers or vents that direct heat ow.

There are three types of passive solar designs

Whether you’re building a new home or retrotting the one you live in now, your passive solar

project will t into one of these three categories. Be sure to contact an architect who specializes

in passive solar designs for your project, no matter what its scale.

A direct-gain design is the simplest passive solar system; the sun shines into the home and

heats a thermal mass—typically a dark-colored masonry oor and/or wall—that holds and

slowly releases the heat as the room cools at night. Some direct-gain designs use water-lled

containers as the thermal mass, since water can store about twice as much heat as the same

volume of masonry. However, a room lled with heavy water containers will need extra

structural support, and the water must be treated regularly to prevent bacterial buildup.

An indirect-gain design uses a thermal mass that’s placed between the windows and the

living space in a home. e most common type of thermal mass is a Trombe wall, an eight- to

16-inch-thick, dark masonry wall with a layer of insulated glass mounted to it. (ere’s an

air space between the glass and the wall.) Heat from the sun is absorbed by the wall and

slowly conducts through the masonry into the home, when the indoor temperature falls

below the temperature of the wall’s surface.

An isolated gain design is a sunspace added onto a home, either as part of the home’s

original design or as a retrot project. Some are designed as year-round rooms, while others

can be closed o from the rest of the house when heating isn’t needed and during warm-

weather months. By the way, even though a greenhouse may seem to be a good design for

solar heating a home, in reality it’s not. e structure’s overhead or sloped glazing is dicult

to shade and can cause overheating of the space (especially during the summer), while the

natural growth process of plants consumes heat energy through the evaporation of water.

iowa energy center

How an air conditioner works

In a conventional central air-condition-

ing system, the evaporator is located

inside the home, while the compressor

sits outside.

compressor

cool air

evaporator

warm air

inside home

outside home

condenser

condenser fan

evaporator fan

Did You Know?

Let your air conditioner run while

you’re on vacation—especially dur-

ing rainy or humid months. Set

your thermostat to 85° F., so the

system occasionally will run and

dehumidify your home. This will

help prevent mold and mildew.

Did you know?

Cooling

Trees are year-round

energy savers

Deciduous trees not only provide shade

during the summer but also allow

the sun’s warmth to reach the house

throughout the winter.

Summer

Winter

Cooling

Make the most of your air-conditioning system

Even though the rst home air conditioner appeared during the late 1920s, home cooling didn’t

become a major consumer of energy until about 30 years ago. Today, it’s hard to imagine not

being able to escape to the comfort of an air-conditioned home on one of Iowa’s hot and humid

summer days.

Across the state, most residential cooling is handled by central air conditioners or room

(window) air conditioners, although energy-ecient air-source heat pumps, add-on heat pumps

and geothermal heat pumps are seeing greatly increased usage. However, no matter what type

of system cools your home, there are many things you can do to cut the cost of running your

air-conditioning unit while still staying comfortable.

Do you really know how an air conditioner works?

Many people think that a room air conditioner or a central air-conditioning system produces

cool air, but technically that’s not accurate. Instead, an air conditioner moves the heat from

inside your home to the outdoors.

More specically, a compressor pumps refrigerant from the evaporator inside your

home to the condenser outside (e evaporator and condenser are made up of coils of copper

tubing surrounded by aluminum ns.) As the warm indoor air passes through the evaporator

coil, the liquid refrigerant inside evaporates; the resulting hot refrigerant gas is then pumped

outdoors through the condenser, where it converts back to a liquid and releases the heat

outdoors.

You can have a major impact on reducing cooling costs at home

ere are four ways to keep your home cool and comfortable at an aordable cost.

Reduce the cooling load on your house.

Explore alternative cooling methods, such as natural ventilation and using fans.

Buy a new, energy-ecient air conditioner.

Increase the eciency of your existing air conditioner.

In the sections that follow, you’ll nd many proven low-cost, low-tech methods for saving

energy (and money) on your cooling needs, in addition to nding out what to consider when

upgrading an existing air conditioner and maintaining your cooling equipment.

Reduce the cooling load on your house

e best strategy for keeping your home cool in the summer is to prevent it from getting hot

in the rst place. is means trying to keep the heat outside from being conducted inside—

and reducing the amount of heat generated by things such as your appliances, television,

computer, lights, water heater, bathing and cooking.

During Iowa’s hot, humid summers, about half of the heat that accumulates in a home

comes from solar gain; the other half comes from air leaks and heat-producing activities inside

the home. In light of these gures, it makes sense to cut these loads before investing in a new

air conditioner. Also, if you can reduce the heat entering your home, you should be able to get

by with a smaller air-conditioning unit when you upgrade to new equipment.

iowa energy center

Cut down on hot spots

Most of the heat gain inside a house comes from sunlight (or solar energy) hitting the roof and

streaming through the windows. Energy conservation measures that block the sun before it

strikes the roof or windows are the most eective ones to implement. Trees and other plants

that provide shade are your best long-term investment for reducing cooling costs.

Solar heat gain is greatest in homes with dark roofs, inadequate insulation and poor attic

ventilation. You can reduce heat gain by a third by shading your house with trees, adding

insulation and ventilating the attic.

Air leaks that allow warm air into your home—and cooled air out—also are a costly problem

if you have air-conditioning, especially in a humid climate such as Iowa’s. For more information

on improving your home’s energy-saving “envelope,” ask your utility or the Iowa Energy Center

for the book, Home Series 1: Home Tightening, Insulation and Ventilation. (See contact list on

page 24.)

Survey your home to save

Cooling

Close windows

during day

Open windows

on cool, low-

humidity nights

Replace leaky windows

Install progammable

thermostat

Set thermostat at

78° F. or higher

Ceiling fan allows

comfort at higher

temperature

Run exhaust fan

in kitchen

Isolate unused rooms

Close chimney damper

Make sure attic is

adequately ventilated

Shade south and

west windows

Use compact

ﬂuorescent

lightbulbs

Vent dryer

outdoors

Use cold water

for wash loads

Run exhaust fan

in bathroom

Take shorter

showers

Seal leaks

in ducts

Have a pro tune up

your cooling system

iowa energy center

Follow these tips to keep your cool

Making a few minor changes in your daily habits—and tackling a few home-improvement

projects around the house—can help you reduce your need for air-conditioning and add to

energy savings during the dog days of summer. While all of the following suggestions may not

be possible or practical for your situation, try incorporating several of them into your summer

routine.

Natural Ventilation

Wind creates areas of positive and negative pressure around your house, so the windows near

upwind areas will be cool air inlets and the windows near suction areas will be warm air

outlets. Try a few tests to nd out which windows to open to maximize natural ventilation.

Don’t locate inlets and outlets directly opposite each other, because the only area that will

be cooled will be in the direct path of the airow. If the air has to take a longer path between

an inlet and an outlet, more of your house will be cooled. Additionally, a slightly opened

window will create a better air current than a fully opened one.

Close windows and doors

during the hottest part

of the day.

If your house is well-tightened and insulated, your inside rooms

should stay relatively cool during mid- to late-afternoon hours.

Open windows on cool,

low-humidity nights.

Natural or (fan-boosted) nighttime ventilation ﬂushes out internal

and solar heat that builds up during the day.

Use fans to boost a

cross breeze.

Blow air from the cool side (the shady side) of your house to the

hotter side.

Close windows early

in the morning.

If you don’t let warm air into your home, you can delay using your

air conditioner until later in the day.

Leave windows closed

when the humidity is high.

If it’s humid and you use your air-conditioning regularly, you’re

better off not opening your windows on cooler days or at night.

Your air conditioner will have to work extra hard to remove excessive

humidity from your house before it can begin to cool it.

Make sure your attic is

adequately ventilated.

Your roof can absorb a tremendous amount of heat during the

summer. If it isn’t properly insulated and ventilated, the temperature

could reach 150° F., which is like having a gigantic radiator above

your living spaces.

A home with a well-

ventilated attic will have a

solid comfort and energy-

eciency advantage

over a home with a poorly

ventilated attic.

Effective attic ventilation helps keep attic temperatures be-

low 110° F. during hot weather, reducing the load on your

air-conditioning system. If your attic gets too hot, the natural

ventilation supplied by sofﬁt vents and attic vents may not be

adequate; you may need to add more vents. In addition, seal air

leaks between the attic and the living spaces below—and add

insulation, if necessary.

Common attic vent types

A combination of high and low roof

vents in any of these conﬁgurations

allows air to circulate naturally and

prevent heat buildup in the attic.

Did You Know?

Your utility may offer options that

can save you money.

•

Special off-peak rates may

be available in late-evening or

early-morning hours, offering

you the opportunity to pay less

for running high-consumption

appliances during those periods.

•

Load-management programs

allow your utility to brieﬂy cut

power to your central air-con-

ditioning system during peak

load periods when the demand

for power is high.

•

Budget billing charges are the

same every month so you won’t

get surprised by an unusually high

power bill; your utility will adjust

the amount regularly.

Did you know?

Sot and continuous ridge vents

Sot and box vents

Sot and gable-end vents

Cooling

iowa energy center

All around your house

e time you spend reducing or eliminating conditions that add heat (and humidity) to your

home will be well spent; the smaller the dierence between the temperature outside and the

temperature inside, the lower your annual cooling bill. Take a tour of your home with the

following lists in hand, to discover what you can do to save energy and cut utility costs.

Living areas

Shade south and west

windows to keep out

the solar heat.

Stopping the sun’s warmth before it gets into your home with awnings

or exterior solar screens is best. If that’s not possible, close inside blinds

and curtains during the day; light colors will reﬂect the most heat.

As an alternative, apply tinted plastic sun-control ﬁlms or reﬂective

coatings to the inside of your windows.

Keep the doors and

windows closed during

the day.

But on cool, low-humidity nights, open the windows and use natural

ventilation (with or without fans) to cool your home.

Keep interior lights

dimmed or turned o

during daylight hours.

Turning on a table lamp for reading in a darkened room is a better

choice than letting the sun stream in through a south or west window.

On the other hand, north or east windows could provide enough light

without signiﬁcantly adding to the heat gain in an individual room.

Check your family’s

lighting use.

Light ﬁxtures generate heat and can add signiﬁcantly to cooling costs.

Turn off lights that really don’t need to be on.

In high-use areas,

replace incandescent

lightbulbs with compact

uorescent units.

Incandescent bulbs are very inefﬁcient, using most of the energy

they consume to create heat. A compact ﬂuorescent lightbulb (CFL)

produces the same light (and less heat) from 65%-75% less energy

than a regular bulb—so a CFL can pay for itself during the life of

the bulb.

Turn o or unplug the

television and other

electronic equipment

when not in use.

Many video and audio components consume power and produce heat

in the standby mode, so unplug them if you won’t be using them for

several days. The only way to turn off the power supply for a device

such as a cordless phone or cable TV box is to unplug it.

Minimize your

computer’s power

consumption when

you’re not using it.

Shut down your computer if you’re not going to be using it for

several hours. If you’re just going to be away for a few minutes, turn

o the monitor—it still uses considerable power in the “screen-saver”

mode—and put the hard drive in your CPU to sleep.

Construct a sunshade over

a concrete patio.

A concrete slab will become a large heat sink during summer months,

reﬂecting sunlight and radiating heat into your house. A shading

structure will solve both problems, as well as making the outdoor

space more usable on hot days.

If you’re building a room

addition, keep cooling

in mind.

Besides adequately insulating and weatherizing the new space,

add 24-inch (or wider) overhangs to shade windows on the sunny

sides of the new room. Also ask your contractor if your present

cooling system can handle the additional load; if not, consider an

energy-efﬁcient supplemental system.

Did You Know?

You should reduce electricity use

during summer peak periods, when

energy demand at your local utility is

highest. With so many people using

electricity for air-conditioning at the

same time, the price of power for

this period may increase, because

it costs the utility more to generate

electricity when consumer demand

soars. Although peak hours can

vary due to weather conditions

and demand, they generally fall

from 3 p.m. to 9 p.m. on the hottest

summer days.

Did you know?

Read the label

When shopping for an air conditioner,

look for the EnergyGuide label that

shows the energy efﬁciency of each

model and allows you to compare the

energy usage of competing systems.

18.0

Cooling

iowa energy center

Kitchen

Cover pots and pans

on the cooktop or

stove.

Cooking creates lots of heat and humidity, so contain it as much as

possible.

Use an exhaust fan. Vent steam and heat from cooking to the outdoors.

Run your dishwasher

late at night.

Start the dishwasher when you go to bed. If it has a timer, set the dish-

washer to run during nonpeak hours in the middle of the night.

Use the most energy-

ecient appliances

for cooking.

Instead of using your stove or oven, use your microwave oven or a

countertop appliance such as a toaster oven, crock-pot, steamer or

pressure cooker.

Replace old, inecient

appliances.

Even if an appliance still has a couple of years of serviceable life,

replacing it with an efﬁcient, ENERGY STAR® qualiﬁed unit is a good

investment.

Use cold water for

cooking.

Heating the water on your stove or cooktop consumes less energy

than using hot water from your water heater—especially if doing

so causes your water heater to cycle.

Check the temperatures

in the refrigerator

and freezer.

The temperatures should run 38°-40° F. in the refrigerator and 0°-5° F. in

the freezer. Setting colder temperature levels wastes energy and makes

these heat-producing appliances run too often.

Laundry

Vent your dryer

outdoors.

Check the lint trap, ducting and exterior vent frequently, to make sure

they’re clear. Excessive lint buildup can make your dryer run longer.

Dry clothes on an

outdoor clothesline.

Wet clothes on an indoor clothesline will add humidity to your home

and increase the load on your air-conditioning system.

Use cold water for

wash loads.

Most clothes and other items will get clean in cold water, if you use the

proper detergent. If you need to wash a warm- or hot-water load, run

it during the late-evening or early-morning hours.

Only wash full loads.

If you don’t have enough clothes for a full load, set the washer’s water

level to match the load’s size.

Insulate the water

heater tank.

The less often it cycles, the more energy you’ll save.

Build a utility room

to enclose the water

heater and laundry.

Separating these heat producers from the rest of the house will reduce

the load on your air-conditioning system. As a bonus, the rest of your

home will be quieter too.

Did You Know?

Many of the air leaks in a central

air-conditioning system occur in the

return air plenum, which is the large

duct above or below the air handler.

When these leaks occur, warm air is

pulled into the system, making

the air conditioner work harder.

If your air conditioner is unable to

satisfactorily cool your home, leaky

ducts may be the cause.

Did you know?

Bathroom

Use an exhaust fan.

Reduce humidity by running an exhaust fan while you’re in the shower.

However, don’t let it run too long, or it will pull cooled air out of your

entire house.

Take shorter baths and

showers.

Long baths and steamy showers add a lot of humidity to your home and

can increase the time your air conditioner runs to overcome it. Install

a water-saving showerhead too.

Shade your compressor

An air-conditioning compressor will

run more efﬁciently if it’s shaded by

a fence, tree or landscaping during

the hottest part of the day. Be sure to

allow enough space around the unit

for adequate air circulation.

Cooling

iowa energy center

Fans

Fans are one of the oldest and most reliable mechanical means of cooling a home, and they use

far less energy than air conditioners. In fact, you conceivably could run several fans and still

consume a smaller amount of energy than you would by running a single room air conditioner.

However, fans don’t cool rooms the same way air conditioners do; instead, fans create a

cooling effect by moving air across your skin. So, opening the windows and using one or

more fans during very hot and humid weather won’t be an eective cooling strategy—especially

if you’re accustomed to using an air conditioner most of the time. Your cooling costs might go

up by a signicant amount, because opening the windows will increase the humidity your

air-conditioning unit needs to remove, forcing the system to run longer than normal.

Window fans and whole-house fans are the best choices for accomplishing power ventilation

in your home. Smaller oor, table and ceiling fans are best used to create a single-room “wind-

chill” eect and are much less eective as whole-house ventilators. (During warm-weather

months, make sure you run ceiling fans in a counterclockwise direction for maximum cooling.)

No matter what type of fan you need, when you go shopping look for a fan that’s ENERGY

STAR qualied—and be sure to note its noise rating too. Also consider a fan with “airfoil-style”

blades that are designed to maximize airow.

Use window fans to create

cross-ventilation on warm,

still days.

Open windows on the shady side of your house and position the

fans so they blow air out of windows on the hot side of the house.

The resulting pressure difference will cause air from the outside to

ﬂow through your house. While this option doesn’t work well on

very hot and humid days, you might be surprised at how well it

works the rest of the time.

A ceiling fan will allow

you to be comfortable at

a higher temperature in

occupied rooms and let

you raise the thermostat

in those areas.

A good ceiling fan should create enough air movement that you will

be comfortable at 82° F. and 80% relative humidity. If you’re using

the fan to supplement or circulate air-conditioning, you should be

able to raise the thermostat a full 4° F. above the standard 78° F.

setting and still be comfortable. For every degree you raise your air

conditioner’s thermostat above 78° F., you’ll save about 3%-5% on

your cooling costs.

Choose the correct ceiling

fan for damp or wet areas.

For a bathroom, buy a fan that has been U.L. listed with a damp

rating. For a location where a fan might come into direct contact

with water—such as a porch—select a fan with a wet rating.

On a cool, low-humidity

night, a whole-house fan

can cut the temperature in

your home in a relatively

short time.

A whole-house fan can reduce your home’s indoor temperature by

up to 20° F., depending on the temperature outside. This type of

fan usually is installed in a hallway ceiling on the top ﬂoor of your

house. It works by pulling the cool outside air from open windows

on the lowest living level of the house into the attic, where warm

air is vented to the outside.

A small fan is not adequate

for cooling large areas.

An oscillating fan, box fan or table fan are good choices for one-

person cooling, circulating the air in a small room or extending the

cooling range of a window- or wall-mounted air conditioner.

Remove heat, humidity

and odors from the

kitchen and bathroom

with a properly sized

exhaust fan.

Don’t leave an exhaust fan on longer—or at a higher speed—than

necessary. In one hour, an exhaust fan can blow a house full of cooled

air outside. Oven heat and shower humidity usually are removed

within 15 minutes; a slightly opened window in the room can speed

up this process.

Did You Know?

You should size a ceiling fan to

the area of the room in which it’s

located.

Room Area

(sq. ft.)

Fan Diameter

(in.)

Up to 75 29-36

75-144 36-42

144-225 44

225-400 50-54

Source: ENERGY STAR and American

Lighting Association

Did you know?

Did You Know?

Ceiling fans are available with a

variety of mounts and downrod

lengths for different slopes and

heights of ceilings. Mount the fan

as closely as possible to the middle

of the room—at least seven feet

above the ﬂoor; if the ceiling allows,

a height of eight or nine feet is better

for optimal airﬂow. A “hugger” fan,

which mounts ﬂush to the ceiling,

will not move as much air because

its blades will be just a few inches

from the ceiling.

Did you know?

Cooling

iowa energy center

Central air-conditioning

A central air conditioner is more than just the largest appliance in a home—it’s part of a

carefully designed system that also incorporates a thermostat and an array of ducts that deliver

and circulate cooled air throughout the structure. In most cases, a central air-conditioning

system is a more energy-ecient choice for regularly cooling a home than using room air

conditioners in three or four dierent rooms.

However, there’s no getting around the fact that a central air conditioner can be fairly

expensive to purchase—and that it must be installed by a qualied heating and cooling

contractor. If your home doesn’t have central air-conditioning—but does have a network of

ducts for a forced-air furnace—you likely can use the same ducts for cooling, as long as they’re

the proper size and free of leaks and obstructions. On the other hand, if your home is heated

by a boiler or electric baseboard units, you’ll need to add a duct system, which can be both

dicult and expensive—especially in a multi-level home, where you might have to sacrice

closet space or build “chases” along walls or in corners to hold the ducts.

You may want to upgrade if your system is 10 to 15 years old

If your home already has central air-conditioning, there are a couple of times to consider

upgrading to a new system. First, start shopping if you will need to spend almost as much (or

more) to repair your present unit as you would to replace it. Second, if your system is 10 years

old or older, it’s probably pretty inecient, and you should consider replacing it with a newer

one. (Some of the best models being sold today are twice as efﬁcient as ones that were available

10 years ago.) Depending on the use, cost of electricity and temperature, the utility bill savings

gained can pay back the cost of a new cooling system within a few years.

is may be the right time to upgrade your heating system too. Since both systems share

components, it doesn’t make sense to add a super-ecient air conditioner to an aging forced-air

furnace—and you’ll likely save money by updating both systems at the same time, as opposed

to changing one now and the other in a couple of years.

When you go shopping, ﬁrst consider the type of unit you need

If you’re adding an air conditioner to an existing furnace—or just upgrading your existing

central air-conditioning unit—you have two choices: a conventional split system (with the

compressor unit outside and the evaporator inside) or an add-on, air-source heat pump that

can cool your home in the summer and help with the heating load in the winter. If you’re

upgrading your entire heating and cooling system (or building a new home), you have other

possibilities; in addition to a conventional split system, look at an air-source heat pump or

a geothermal heat pump. (Heat pumps operate like conventional air conditioners, except

they also run in reverse to provide heat during cold weather.) For more information on heat

pumps, see page 7 in the Heating section of this book, contact your local utility or visit the Iowa

Heat Pump Association Web site at http://www.iaheatpump.org.

No matter which type of cooling unit you choose, be sure to fully explore all of the energy-

saving options available, including two-stage compressors that run in a special energy-saving

mode on mild or less-humid days, new compressor designs with fewer moving parts than used

in the past and environmentally friendly refrigerants.

Bigger isn’t necessarily better

According to the U.S. Department of Energy, national surveys have indicated that more than

half of all heating and cooling contractors don’t properly size heating and cooling systems.

For air-conditioning systems, oversizing is a real problem; not only do oversized units consume

more energy, they also remove less moisture from your home and have a shorter service life.

Did You Know?

One way to get around all of the

construction necessary for adding

ducts in a home built without

them is to use a mini-duct central

air-conditioning system. It uses

a conventional air-conditioning

compressor or heat pump outdoors

and a special high-powered blower

in the basement (the preferred

location) or the attic. The system

uses ducts with a two-inch inside

diameter, so it’s easy to run them

through walls or the corners of

closets to rooms above. You can

buy heavily insulated ducts to run

through an attic or other unﬁnished

space, and ceiling, wall and ﬂoor

outlets are available.

Did you know?

Central air conditioner

The most common residential central

air conditioner is a split system where

the evaporator is located inside, with

the blower and other components of

the furnace (or heat pump) connecting

to ducts that run throughout the

home. The outdoor unit includes the

compressor and condenser; position

it on the north or east side of your

home, where it will be shielded from

intense sunlight. Leave four to ﬁve

feet of open air space around the unit

to ensure enough air circulation for

proper operation.

Cooling

Return

grille

Fan

Compressor

Condenser

Outdoor switch box

Refrigerant lines

iowa energy center

e size of central air conditioners is measured in Btu/hour (British thermal units per

hour). A reputable contractor will need to do a lot of investigating and calculating on a

worksheet or computer to come up with the correct rating for your cooling system, considering

things such as the size, style, orientation and shading of your home; insulation levels; window

types, locations and sizes; air inltration; location and condition of ducts; lighting and

appliances in use; weather; your family’s lifestyle; and your comfort preferences.

e written bid you receive should detail the sizing calculations in writing. Don’t accept

an estimate that is based only on the size of the existing unit, the square footage of your house

or any other “rule of thumb.”

What’s SEER?

Buying an inecient central air conditioner will guarantee high electric bills during the device’s

lifetime, so buy the most energy-ecient unit your budget allows. A central air conditioner’s

Seasonal Energy Eciency Rating—SEER—measures the seasonal performance of the unit

based on the cooling accomplished.

During the past few years, new technologies have helped the SEER ratings on the most

efficient central air conditioners to rise above 20. The minimum SEER required by the

Department of Energy for central air conditioners is 13, while the ENERGY STAR specication

is 14. Both are a long way from a 1970’s-vintage central air conditioner with a SEER of 6; by

replacing that unit today with one that has a SEER of 20, you could cut your air-conditioning

costs by about two-thirds.

Regular maintenance equals lower costs

A spring tune-up of your air-conditioning system will keep it working at top eciency.

Call a qualied heating and cooling specialist to handle these items.

Check the refrigerant charge and repair leaks. A system that is undercharged by 10 percent

may drop 20 percent in eciency. By the same token, an overcharged system can cause the

refrigerant to ood and damage the air-conditioning unit.

Oil the bearings on the fan and compressor, if they’re not sealed.

Test the compressor and blower controls.

Clean the condenser and fan.

Check all electrical connections for corrosion.

Clean the evaporator and blower, and ush the drain line.

Readjust the duct dampers.

Check the temperature rise of the outside unit while it’s running, and check the temperature

drop through the indoor coil.

Test overall operation of the unit (including thermostat).

You may be able to handle the following maintenance items. Read the instructions

that came with your system, and be sure to turn o power to the unit before you start.

Check lters monthly and clean or replace them as needed.

Once a year, clean the evaporator coil with a biodegradable cleaner and a so brush if it’s

easily accessible; if not, leave the job for a trained technician.

Clean the condensate pan, too, and make sure the drain hose isn’t plugged.

When dirt has built up, clean the condenser coils. Use a biodegradable cleaner and a so

brush to gently clean the coils and ush them with clean water. Clean the blower’s fan blades

too. Don’t just blast the parts with a hose!

Straighten the fins in evaporator and condenser coils with a “fin comb” from an air-

conditioning parts supplier.

Remove debris around condensing unit and trim bushes and grass to maintain airow.

Always turn off the power to your

central air-conditioning unit at

the shutoff located next to the

compressor outside your home or

the circuit-breaker panel (or fuse

box) before performing any clean-

ing or maintenance tasks.

CAUTION!

Cooling

Did You Know?

A central air-conditioning system

or heat pump can heat water with

the addition of a desuperheater—

a heat recovery unit that cap-

tures waste heat from a central

air conditioner, heat pump or

geothermal heat pump and uses it

to heat the water in a water heater.

Since the desuperheater only works

when the system’s compressor

is running—and the equipment is

relatively expensive—the payback

period for a home in Iowa’s climate

will be pretty slow. Ask a heating

and cooling contractor for a detailed

analysis on whether a desuperheater

makes sense for your home.

Did you know?

iowa energy center

Room air conditioners

Room air conditioners—sometimes called window units—mount in a hole cut into an exterior

wall or in a window frame. (Portable units that roll from room to room and vent through a

window also are available.) Room air-conditioning units are designed to cool one room at a

time, and you would need multiple units to cool an entire house. However, room air conditioners

are a good choice if you only need to cool one or two rooms, live in an apartment or own a very

small, well-insulated home. One or more energy-ecient room units can be less costly to run

than an older, full-sized central air-conditioning system; on the other hand,

a couple of older room units can be more expensive to operate than a new central unit.

Energy-ecient room air conditioners are moderately inexpensive and fairly easy to install

in a wall using basic carpentry skills—although some models weigh around 100 pounds, so

installation could be a two-person job. e opening around the unit, whether it’s mounted in a

wall or window, must be sealed to prevent air leaks. And if you don’t remove the unit every fall

for winter storage, cover it with a tted, insulated blanket made specically for that purpose to

keep cold air from inltrating your home.

When shopping for a new unit, consider size and efﬁciency

A room air conditioner that’s sized correctly will handle both the heat and humidity in a room.

Some people buy an oversized unit, assuming that it will do a better job of cooling. But

remember that an air conditioner must remove heat and humidity from the air, and it’s designed

to do both during a normal cycle. A unit that’s too large may cool a room quickly, but the

resulting short cycle won’t allow it to reduce the humidity to an acceptable level.

e cooling capacity (size) of a room air conditioner is

measured in Btu/hour (British thermal units per hour) and

is dependent on the square footage of the room you want to

cool. Aer guring the square footage of the room, use the

chart (right) to determine what size air conditioner best ts

your needs. If the room is on the sunny side of your house,

increase the air conditioner’s capacity by 10 percent; if the

room is shaded, subtract 10 percent. For a kitchen-mounted

unit, boost the capacity by 4,000 Btu/hour. And if more than

two people usually occupy the room, add 600 Btu/hour for

every additional person.

At the store, check the yellow EnergyGuide label on each

air conditioner for its EER—Energy Eciency Ratio—the

unit’s cooling output (Btu/hour) divided by its power

consumption. Average units have an EER around 10, but buy

a unit with an EER of 11 or higher for maximum eciency;

you’ll more than make up the higher cost of the more

ecient unit through future energy savings.

What about maintenance?

Aer unplugging the air conditioner, check its owner’s manual for tips on cleaning or replacing

the inside air lter. (Usually you have to remove an access panel to reach it.) en gently clean

the aluminum ns on the evaporator coils behind the lter with a so brush, working in the

same direction the ns run. Finally, use a biodegradable disinfectant solution to ush the drain

pan in the bottom of the unit that collects condensation from the evaporator coils and directs

it outside. is is a good time to make sure the pan is draining completely too.

You also can remove the outside cover of the air conditioner and use a so brush and

disinfectant solution to carefully clean the condenser coils and aluminum ns. If the dirt

doesn’t come o easily, don’t scrub too hard or you may damage the ns.

Call a professional service technician for all other maintenance work.

Room Area

(sq. ft.)

Capacity

(Btu/hour)

100-150 5,000

150-250 6,000

250-350 7,000

350-400 9,000

400-450 10,000

450-550 12,000

550-700 14,000

700-1,000 18,000

Source: ENERGY STAR

Room (window) air conditioner

A room air conditioner functions in the

same way as a central air-conditioning

system, but on a much smaller scale.

Made in the shade

For peak operating efﬁciency, locate

room air conditioners on the north side

of your home or in a shaded area—and,

if possible, in the middle of each room

for better air distribution.

Don’t remove the third prong on

the plug for a room air conditioner

to make the plug ﬁt into an older

two-slot wall outlet. The third

prong is a safety device that

protects you from a shock in the

event of a malfunction in the unit.

Instead, call an electrician to install

a properly grounded outlet for the

exclusive use of the air conditioner.

In addition, never use an extension

cord with an air conditioner; plug

the unit’s cord directly into the

closest outlet.

CAUTION!

Cooling

iowa energy center

Landscaping for comfort

Besides making your homestead a greener and more beautiful place to live, trees and land-

scaping are the most eective long-term measures for reducing your home’s energy con-

sumption for heating and cooling. For example, deciduous trees—which are bare in the winter

and leafy during the summer—allow winter sunshine to come through their branches when

it’s cold and warm your home, and screen out the summer sun when the branches are lled

with leaves. Choose deciduous trees that don’t have a heavy branch structure (which could block

the sun), and plant them on the east, south and west sides of your home for the maximum

shading eect. On the north and west sides of your home, use evergreens as a windbreak to

reduce the chilling eect of winter winds. And add low bushes or hedges to direct summer

breezes toward your home.

Mature trees and shrubs “protecting” your home can have a dramatic eect on utility bills,

according to the U.S. Department of Energy Oce of Energy Eciency and Renewable Energy.

For example, an energy-saving landscaping design can cut heating bills by about one-third

during cold-weather months. e potential savings during warm-weather months are equally

dramatic: A well-planned landscape can reduce an unshaded home’s summer air-

conditioning costs by 15 to 50 percent, depending on how tight the structure is and how

well it’s insulated.

Keep these things in mind as you plan your

energy-saving landscape design:

Talk with local tree and landscaping experts

or state extension sta for help in choosing the

right trees for your home size and soil type.

Plant trees so there will be enough space

between the trees at maturity and the house

(for both branches and root systems). Consider

the proximity to neighbors’ homes too.

A windbreak can reduce wind speed for as far

as 30 times the height of the windbreak.

However, for maximum effect, plant your

windbreak a distance from your home that’s

two to ve times the mature height of the trees

you’re using.

For the most eective type of winter windbreak

that slows both wind and snow driing, plant shrubs, build a fence or create an earth berm

on the windward side—near the bases—of tall evergreens.

Ultimately, trees should shade your roof, as well as the sides of your home during late spring,

summer and early fall. Dark-colored home exteriors absorb up to 90 percent of the sun’s

radiant energy; some of this heat gain is conducted to the interior of your home, no matter

how well it’s insulated.

e more shade you have, the more eectively you can use natural ventilation. Shade makes

the air around the house cooler, and it prevents solar heat from being conducted indoors.

Temperatures directly under trees can be up to 25° F. cooler than air temperatures around

nearby blacktop, due to shading and evaporative cooling.

Use light-colored mulch or ground cover to reect heat away from your house.

Trees are a good investment. Studies by real estate agents and professional foresters estimate

that trees raise a home’s resale value seven to 20 percent. In addition, your home’s roof and

siding materials will last longer due to reduced exposure to the sun’s ultraviolet rays.

Create an energy-saving

landscape

A carefully developed landscape can

reduce your annual heating and cool-

ing bills by a substantial amount.

Did You Know?

The National Arbor Day Foundation’s

Web site at http://www.arborday.org

is a good resource for information

on choosing the right trees for your

energy-saving landscape. You can

search by tree category, soil type, sun

exposure and hardiness zone — most

of Iowa is in Zone 5—and even

order trees.

Did you know?

Landscaping

iowa energy center

Open window coverings

on south-facing windows

to take advantage of solar

heat gain.

Letting the sun shine into your home—even through just a couple

of south-facing windows—can provide enough heat to reduce the

load on your heating system. As soon as the sun stops shining into

your home, cover the windows to minimize heat loss.

Cover east-, north- and

west-facing windows

whenever possible.

Heavy curtains or insulated shades are best for reducing chills when

it’s dark. Also keep windows covered during the day—unless you need

the natural light—since there will be little solar heat gain.

Keep the doors and

windows closed as

much as possible.

Besides diluting the heated air in your home, a wintry blast reaching

your thermostat can fool it into thinking the whole house is too cool

and signal your heating system to start unnecessarily.

Repair and install

storm windows.

Storm windows can reduce heat loss by 25%-50%. Make sure the

glass isn’t cracked and that the gaskets are in good shape.

Wash south-facing

windows.

Dirt and grime on windows can reﬂect part of the solar heat gain

you’d otherwise get from these windows.

Trim trees and bushes in

front of windows.

Deciduous trees and shrubs will drop their leaves to let in sunshine.

Cut back other types that block the low winter sun.

Windows

A window is a complex system

Besides style and frame materials,

there are many other factors to

evaluate when buying windows for

your home. (Top ) Heat effects include

U-factor (heat loss), convection (glazing

and low-conductivity gas between

panes) and air leakage (inﬁltration).

(Bottom) Radiation effects consist of

solar heat gain coefﬁcient (amount of

sun’s radiation transmitted through

window), visible transmittance (level

of daylight coming through window)

and emissivity (low-e coating on glass

to reﬂect heat back into the heated

space and reduce heat loss). Some

manufacturers also include a rating

for condensation, on a scale from 1 to

100; the higher the number, the better

a window resists condensation.

Heat eects

convection

air leakage

heat loss

Radiation eects

low-e coating

solar gain

daylight

Windows

You may not think of your windows as being an integral part of your home’s heating system,

but consider this: According to the U.S. Department of Energy, windows account for 10 to

25 percent of your heating bill. As a result, it’s important to make the most of their

virtues—light, view, solar gain and comfort—and reduce their vices—heat loss at night, air

leaks and that chilly feeling when you’re standing nearby.

Of course, solar heat gain through windows during the summer will increase your

home’s air-conditioning load and raise cooling costs. See pages 13 and 19 for tips on re-

ducing the eects of the sun’s warmth on your house during the warm-weather months.

Replace leaky old windows with energy-saving units

If you’re remodeling or building a new home, buy the most energy-ecient windows you can

aord; your being able to use a smaller-capacity heating and cooling system should oset their

higher initial installation cost. Shop for windows that include double or triple glazing,

a low-conductivity gas such as argon between the panes and a low-e (emissivity)

coating on the glass. Also look for high-quality wood, clad or insulated vinyl window frames.

e National Fenestration Rating Council rates windows in these performance categories,

although not all window manufacturers display them on the window packaging.

U-factor is the rate of heat loss through a window. Lower is better, so look for double- or

triple-glazed windows with a U-value of 0.35 or below.

Solar heat gain coefﬁcient (SHGC) is the amount of solar radiation transmitted through

a window. To maximize the benet of warmth from the sun, choose the highest SHGC

possible (about 0.30-0.60) for the appropriate U-factor.

Visible transmittance indicates the amount of visible light transmitted through a window.

To maximize daylight, look for windows with the highest visible transmittance rating.

Air leakage measures the heat loss (and gain) that occurs by air inltration through a

window. e lower the number, the less air will go through a window assembly; look for a

rating of .30 or less.

Check the Web sites of the National Fenestration Rating Council (http://www.nfrc.org/)

and the Ecient Windows Collaborative (http://www.ecientwindows.org/) for details.

Did You Know?

When you install a programmable

thermostat, be sure to recycle the

unit you’re replacing. Many older

wall thermostats equipped with

a dial or lever contain a glass-

bulb mercury switch to provide

efﬁcient temperature control.

Mercury can be harmful to the

environment and human health.

The likelihood of being exposed

to the mercury in the switch is very

low, but you should handle the

thermostat carefully after removing

it and dispose of it properly.

The not-for-profit Thermostat

Recycling Corporation facilitates

the collection of used mercury-

switch thermostats. To find out if

distributors or contractors in your area

participate in this program, go to

http://www.nema.org/gov/ehs/trc.

iowa energy center

Typical programmable thermostat

settings for winter

In this example showing heating set-

tings, the system will warm the house

to 70° by the time the family wakes up

during weekdays, but wait until 8:00

a.m. on weekends because the family

sleeps later. After everyone leaves for

work or school Monday through Friday,

the thermostat will let the house cool

to 60°—and raise the temperature

back to 70° again for everyone’s arriv-

al around 5:30 p.m. On Saturday and

Sunday, the program varies according

to the family’s schedule.

Wake

70°

Leave

60°

Return

70°

Sleep

62°

Mon 6:00a 7:30a 5:30p

10:00p

Tue 6:00a 7:30a 5:30p

10:00p

Wed 6:00a 7:30a 5:30p

10:00p

Thu 6:00a 7:30a 5:30p

10:00p

Fri 6:00a 7:30a 5:30p 11 : 0 0 p

Sat 8:00a 9:00a 6:00p 11 : 0 0 p

Sun 8:00a 9:30a 1:30p

10:00p

Thermostats

A thermostat is a simple device—it’s just a temperature-controlled on/o switch for your heating

and cooling system. However, a thermostat can have a major impact on your annual heating

and cooling costs; during cold weather set it as low as possible, and during

warm weather set it as high as possible—without sacricing comfort. According to the U.S.

Department of Energy, setting back your thermostat by 10 to 15 percent for eight hours a day

can reduce your annual heating and cooling bill by as much as ten percent.

This energy saver can pay for itself in less than a year

A programmable thermostat—a thermostat combined with a clock—can handle daily system

temperature changes for you automatically, all year long. Once you set a programmable

thermostat, you can forget it—unless you want to change the program. In fact, some pro-

grammable thermostats come preprogrammed from the factory, so you can use the standard

program or easily modify it to meet your family’s needs.

For example, during warm-weather months, the thermostat program will cycle the cooling

system so your home is a comfortable 78° when you get up in the morning—and then allow the

temperature to go to 85° during the day while you’re at work. Later, when you arrive home from

work, the system will have cooled your home back to 78° again. Aer you go to bed, the

thermostat can raise the temperature a few degrees to save even more energy before repeating

the cycle the next day.

Look for these features

e least-expensive (under $40) ENERGY STAR® qualied programmable thermostats are

pretty basic and oer a single program with four settings—wake, leave (day), return (night) and

sleep—for weekdays and a second program with four settings for the weekend. Some also

include a few other features such as battery backup for the program, a monitor that indicates

when to change the furnace lter and a temporary program override to use, for example, if you

stay home from work.

However, if your budget allows, spend $50-$100 (or more) for a smart programmable

thermostat. A “7-day” smart thermostat, for instance, will let you set a separate program for

each day of the week. Some upscale thermostats oer six programs per day, automatic switching

between heating and cooling modes and one-button hold temperature and vacation settings.

In addition, several thermostats include a separate program for the blower fan, as well as oering

control of a whole-house humidier (for winter), a variable-speed fan blower (for humidity

control during summer) or a fresh-air ventilator (year-round). You even can remove most

programmable thermostats from the wall to program them—and a couple come with remote

controls, so you can change thermostat settings from anywhere in your home.

Finally, look for a thermostat with an advanced recovery or ramping feature that helps your

heating and cooling system deliver the correct temperature at the right time, in the most

economical way possible. is feature monitors indoor and outdoor temperatures and humidity

and gradually brings your home to the requested temperature (usually over a period of hours),

so the system doesn’t have to deal with a large temperature shi all at once.

Mount your thermostat away from windows or doors; sunlight streaming through a

window or a chilly breeze from an open door can trick your thermostat into thinking your heating

or cooling system should cycle.

Many thermostats—from the simplest, most inexpensive ones

to the fanciest, programmable units—are designed for do-it-yourself installation. Just turn o

the power to your heating and cooling system, remove the old thermostat and attach the existing

system wires to the correct terminals on the new thermostat. However, if the wires aren’t

color-coded or the new thermostat requires additional wires, call a professional installer for

help.

Did you know?

iowa energy center

Out with the bad air,

in with the good

Although there are several different

styles of HRV, they’re all designed to

do the same thing: exhaust stale air

from—and bring fresh air into—a

home. When shopping for an HRV,

be sure to consider the controls

that come with each unit. Certain

HRVs include automatic controls

with humidity sensors, while others

include only manual fan speed

and/or timer switches. Some HRVs

also include a defrost cycle or vent

to prevent buildup of ice during very

cold weather.

Turbocharge your ducts

If a room at the end of a long duct run

always seems to be cooler than other

rooms—and you’ve already ﬁxed

duct leaks, insulated the ducts and

rebalanced the whole duct system—

an electric booster fan that mounts to

the problem duct may help.

Heat recovery ventilators/Ducts

Heat recovery ventilators

One of the problems with new homes that are constructed very tightly—or existing ones that

are remodeled to signicantly reduce air leaks—is that the air inside can get pretty stale. Besides

stuy air, some of the signs of inadequate ventilation in a home include mold and mildew

growth on walls, excessive condensation on windows and other cold surfaces (during the

heating season) and high humidity (any time of year); for your family, the symptoms include

headaches, dizziness, fatigue and respiratory problems.

ere are many sources of indoor pollution, including things such as fuel-burning heating

systems and appliances, gasses released by adhesives used in building materials, vapors from

home-cleaning products and radon. Eliminating these pollution sources from your home is

only part of the answer; you also need to bring fresh outdoor air into your home.

Of course, you can open a couple of windows to help reduce the pollution, but obviously

that defeats the energy-saving purpose of creating a tight home in the rst place. A better idea

is to install an air-to-air heat recovery ventilator (HRV) to remove pollutants and bring fresh

air into your home, without wasting your energy dollars. An HRV is designed to exchange

contaminated air from your home with fresh air from outside—without wasting the energy

dollars you’ve spent to heat or cool your home.

During the winter, stale, heated air from your home runs through a heat exchanger in the

HRV that captures up to 80 percent of the air’s heat energy, before exhausting the contaminated

air outdoors. At the same time, fresh outdoor air passing through the heat exchanger is warmed

before it’s released inside the home, either through existing heating system ducts or a separate

system of ducts connected only to the heat exchanger. During the summer, stale, cooled air

runs through the heat exchanger, cooling the fresh, hot outdoor air before it reaches the

distribution ducts.

A similar system, called an energy recovery ventilator (ERV), adds an important

function to the ventilation process: It also transfers humidity. During cold months, the ERV

sends humidity from the exhaust air to the incoming fresh air, helping to raise the home’s

humidity to a comfortable level—unless there’s already enough humidity in the home, at which

point the ERV vents the excess humidity outdoors. During warm months, the ERV can exhaust

humid air outside, assisting the central air-conditioning unit.

Note that the need for humidity control is dierent in every house on every day of the year.

Ask your heating and cooling contractor for recommendations on using an HRV or ERV.

Ducts

According to ENERGY STAR®, leaky ducts can reduce a home heating and cooling system’s ec-

iency by up to 20 percent. at can add up to hundreds of dollars per year on your energy bills!

As a result, it’s very important to hire a professional to pressure test and inspect the

network of ducts in your home to ensure that all the heated or cooled air is reaching the

appropriate rooms. e technician should look for loose joints, holes or leaks and x those

problems using metal-backed tape (not cloth-backed duct tape), mastic or an aerosol-based

sealing material. In addition, insulate the ducts with a material rated R-6 or higher—especially

if they run through an unheated basement or crawl space. Remember that doing so will make

those areas colder, so insulate the walls in the basement or crawl space too.

Another common problem with ducted systems is uneven temperatures in rooms

throughout a home. is situation may be caused by leaks, but it also may be due to the duct

system’s original design. If each branch of the duct network doesn’t include simple metal

dampers in the ducts, have them installed; then you’ll be able to adjust the amount of condi-

tioned air that goes to each room and balance the temperatures throughout your home.

If installing dampers is not a practical solution—for example, if the supply ducts are hidden

above a nished basement ceiling—add adjustable registers in each room.

fresh air In

stale air

from house

stale air

to outside

fresh air

to house

lters

heat exchanger

blowers

iowa energy center

Heating and Cooling

Did You Know?

Energy specialists offer many differ-

ent services, so make sure you ask

the right questions and provide

enough information to find one

that specializes in the type of work

you need.

•

A home energy rater, for example,

is a specialized contractor who

performs a standardized evalua-

tion of the energy efficiency of

a home. The evaluation should

include an on-site inspection,

air leakage test of your home

and ductwork, computer analysis

of estimated savings and home

energy rating.

•

A n energy auditor, on the other

hand, completes an evaluation of

the efﬁciency of a home that may

or may not be as comprehensive

as a home energy rating.

•

A heating and cooling contractor

sells, services and installs furnaces,

boilers, central air conditioners,

heat pumps, ducts and program-

mable thermostats. Some heating

and cooling contractors also

provide specialized services such

as airﬂow balancing, duct sealing

and energy or comfort audits.

Source:

ENERGY STAR

Did you know?

Hiring a contractor

iowa energy center

Hiring a contractor/Old equipment

Disposing of old equipment

In the past, old furnaces and air conditioners oen were dumped in landlls or even ditches.

Very few of these units were recycled, and the hazardous materials in them—refrigerant,

PCBs and mercury—contaminated the soil and ground water. Today, the state requires that a

demanufacturer remove the hazardous components from discarded appliances, before

disposing of them in an environmentally sound manner and recycling the remaining metals.

ere are many locations across the state that gather discarded furnaces, air conditioners

and appliances for processing by a demanufacturer. To locate a collection site near you, contact

your local solid waste agency or go to the Waste Management Web site of the Iowa Department

of Natural Resources at http://www.iowadnr.com/waste/.

1 Be prepared. Find out about license and insurance requirements for contractors in

your area. Before you call a contractor, know the model of your current heating and

cooling system, as well as its maintenance history.

Consider a certied professional. Look for a contractor who employs technicians

certied by NATE (North American Technician Excellence), the leading industry-

supported testing and certication program.

3 Call references. Ask each contractor for customer references, and call them. Ask about

the contractor’s installation or service performance—and if the job was completed on

time and within budget.

4 Find special oers. A heating and cooling system is one of the largest purchases you’ll

make as a homeowner. Keep your costs down by checking around for available rebates

on energy-ecient, ENERGY STAR® qualied heating and cooling equipment. Begin

your search at www.energystar.gov, and ask the contractors and your utility company too.

5 Look for ENERGY STAR qualified products. They meet strict energy-efficiency

guidelines set by the U.S. Environmental Protection Agency and oer signicant long-

term energy savings. Contractors should be able to show you calculations of savings

for ENERGY STAR heating and cooling equipment.

6 Expect a home evaluation. e contractor should spend signicant time inspecting

your current system and home to assess your needs. A bigger system isn’t always better;

a contractor should size the heating and cooling system based on criteria such as the

square footage of your house, level of insulation and total window area. A good

contractor also will inspect your duct system (if applicable) for air leaks and insulation,

as well as measure airow to make sure it meets manufacturers’ specications.

Get written, itemized estimates. When comparing bids, be sure to consider

warranties and equipment disposal.

8 Get it in ink. Sign a written proposal with a contractor before work gets started. e

document should specify project cost, model numbers, schedule and warranty.

9 Pass it on. Tell friends and family about ENERGY STAR and a good contractor.

10 Get the ENERGY STAR Guide. For information on keeping your home comfortable

year-round, download the ENERGY STAR Guide to Energy Ecient Cooling and

Heating at http://www.energystar.gov or call 888-782-7937 to order a copy.

for more information

Alliance to Save Energy

1850 M Street, NW, Suite 600

Washington, DC 20036

Phone: 202-857-0666

Web site: http://www.ase.org/

Alliant Energy

4902 North Biltmore Lane

P.O. Box 77007

Madison, WI 53707-1007

Phone: 800-255-4268

Web site: http://www.alliantenergy.com/

American Council for an

Energy-Efﬁcient Economy

1001 Connecticut Avenue, NW, Suite 801

Washington, DC 20036

Phone: 202-429-8873

Fax: 202-429-2248

Web site: http://www.aceee.org/

Aquila, Inc.

1701 48th Street, Suite 260

West Des Moines, IA 50266

Phone:

816-421-6600

Web site: http://

www.aquila.com/

Atmos Energy Corporation

24 South 10th Street

Keokuk, IA 52632

Phone:

888-286-6700

Web site: http://

www.atmosenergy.com/

Energy Efﬁcient Rehab Advisor

Web site: http://rehabadvisor.pathnet.org/

ENERGY STAR®

1200 Pennsylvania Avenue, NW

Washington, DC 20460

Phone: 888-782-7937

Web site: http://www.energystar.gov/

Federal Trade Commission (FTC)

Consumer Response Center

600 Pennsylvania Avenue, NW

Washington, DC 20580

Phone: 877-382-4357

Web site: http://www.ftc.gov/appliances/

Gas Appliance Manufacturers

Association (GAMA)

2107 Wilson Boulevard, Suite 600

Arlington, VA 22201

Phone: 703-525-7060

Web site: http://www.gamanet.org/

Home Energy Saver

Environmental Energy Technologies Division

at the Lawrence Berkeley National Laboratory

Web site: http://hes.lbl.gov/

IowaENERGY.org

Web site: http://www.iowaenergy.org/

Iowa Association of Electric Cooperatives

8525 Douglas, Suite 48

Des Moines, IA 50322-2992

Phone: 515-276-5350

Fax: 515-276-7946

Web site: http://www.iowarec.org/

Iowa Department of Human Rights/

Division of Community Action Agencies

Lucas State Ofﬁce Building

321 E. 12th Street

Des Moines, IA 50319

Phone: 515-281-3861

Fax: 515 -242- 6119

Web site: http://www.state.ia.us/government/

dhr/caa/

Iowa Association of Municipal Utilities

1735 NE 70th Avenue

Ankeny, IA 50021-9353

Phone: 515-289-1999

Fax: 515-289-2499

Web site: http://www.iamu.org/

Iowa Department of Natural Resources

502 E. 9th Street

Des Moines, IA 50319-0034

Phone: 515-281-5918

Web site: http://www.iowadnr.gov/

Iowa Ofﬁce of Energy Independence

Lucas State Ofﬁce Building

312 E. 12th Street

Des Moines, IA 50319

Phone: 515-281-0187

Web site: http://www.energy.iowa.gov/

Iowa Renewable Energy Association

P.O. Box 3405

Iowa City, IA 52244-3405

Phone: 319-643-3160

Web site: http://www.irenew.org/

Iowa State University Extension

Answer Line Phone: 800-262-3804

Web site: http://www.extension.iastate.edu/

answerline/

or http://www.extension.iastate.edu/housing/

MidAmerican Energy

666 Grand Avenue, Suite 500

Des Moines, IA 50309-2580

Phone: 888-427-5632

Web site: http://www.midamericanenergy.com/

U.S. Department of Energy Ofﬁce of

Energy Efﬁciency and Renewable Energy

Forrestal Building

U.S. Department of Energy

1000 Independence Avenue, SW

Washington, DC 20585

Phone: 877-337-3463

Web site: http://www.eere.energy.gov/

U.S. Environmental Protection Agency

Ariel Rios Building

1200 Pennsylvania Avenue, NW

Washington, DC 20460

Phone: 202-272-0167

Web site: http://www.epa.gov/

This is an Iowa Energy Center publication.

e Iowa Energy Center is a research, demonstration and education organization dedicated

to improving Iowa’s energy eciency and use of renewable energy. e Energy Center meets

its goals by developing in-house energy research and education programs and by sponsoring

energy projects developed by other groups. e projects supported by the Energy Center, which

vary in size and complexity, are conducted throughout the state in Iowa’s universities, col-

leges, community colleges and private nonprot organizations.

Iowa Energy Center

2521 University Boulevard, Suite 124, Ames, IA 50010-8229

Phone: 515-294-8819 | Fax: 515-294-9912 | E-mail: iec@energy.iastate.edu

Web site: http://www.energy.iastate.edu