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Remodeling Kitchens:
A Smorgasbord of Energy Savings
by Bruce Sullivan
The kitchen offers a greater variety of
ways to cut energy costs during remodeling than anywhere else in the home.
The kitchen is the
busiest room in the house. It's often the social hub of household life.
And it's the room most likely to be remodeled--repeatedly--over the life
of a house.
The kitchen also represents a concentration of
household energy use--anywhere from 20% to 40% of a home's consumption.
It should be no surprise then that kitchen remodeling can mean introducing
a host of new energy-saving features, or making major energy blunders.
Here are a few tips to consider to avoid the remodeler's lament: "Oh,
no. I should have done it the other way!"
Layout and Design
The growing trend in kitchens today is "universal
design," which recognizes that homes are occupied by people of different
ages and lifestyles. Counters vary in height and depth and have rounded
corners for safety; lighting is generous and functional; knobs are easy
to see and grab; shelves are within reach, with more rollout access. The
workspace is arranged to accommodate two or more cooks at a time, and they
can prepare meals sitting or standing.
Along with being people-friendly, kitchens are
becoming more resource-friendly. For waste disposal, removable recycling
and composting receptacles are now built into the design. "Green"
building materials and non-toxic products are increasingly used in construction,
and new government standards mean the typical renovated kitchen will have
low-flow faucets and some new energy-efficient appliances. Certainly these
advances mean savings and convenience, but for even greater savings and
genuine comfort, so much more can be done.
Energy as Part of the Plan
When contemplating any remodeling job, remember
that houses have a certain ecology: everything is connected to everything
else. Heating, cooling, insulation, ventilation, lighting, and indoor air
quality all affect one another. Nowhere is this more evident than in kitchens,
where heat, moisture, and cooking odors can create discomfort in the immediate
area as well as elsewhere in the home.
It is tempting to expand the floor area in kitchens
during a remodel, but it may not be necessary. Remember: a larger space
may use more operating energy and is likely to use more building materials.
Take the opportunity to make better use of the existing floor area through
highly organized storage and work space arrangements. It's the best way
to reduce energy and resource use.
If the space will be enlarged, a heating or cooling
system with greater capacity may be a consideration. However, be cautious.
First, most residential systems are oversized already. Second, extra insulation,
air sealing, proper window orientation, and other structural improvements
reduce heating and cooling needs. Pay careful attention to how the redesigned
space will be heated, cooled, and ventilated--and how it will influence
the rest of the house. Thoughtful redesigns can even correct pre-existing
problems such as drafts, stuffiness, and condensation.
Lighting presents similar opportunities for enhancing
the home while addressing specific needs in the kitchen. Keep in mind that
natural daylight is the most pleasant and efficient lighting source. Daylighting
is achieved primarily through proper design, so it shouldn't cost more
if windows were already on the replacement list.
Kitchen designers strive to improve the cook's
efficiency by carefully arranging workspaces. Cooks obviously take top
priority, but don't forget that appliances work, too. The design should
take into account how placement affects their efficiency. For example,
a refrigerator placed next to an oven or in direct sunlight will work harder
and use more energy.
Appliances
New appliances are favorite items in a remodeled
kitchen. That's good for saving energy, because modern appliances are far
more efficient than their predecessors. It will save money over the long
run to choose the most energy-efficient model that fits the budget. Bright
yellow "Energy Guide" labels, now required on refrigerators and
dishwashers, will help when comparing the efficiency of different models.
Refrigerators
Be especially careful in choosing a refrigerator,
because it will use more energy than any other kitchen appliance. Fortunately,
great strides have been made in refrigerator efficiency. An average 1995
refrigerator uses less than one-third the energy of a similar model built
in the 1970s. Again, size makes a difference--as a rule, larger models
use more energy to operate and more resources to build, so select the smallest
size that fits the need. A side-by-side refrigerator/freezer is less efficient
than one with the freezer on the top or bottom; automatic ice makers and
through-the-door dispensers will add to energy use and to the cost of the
refrigerator; and manual defrost is better than automatic defrost (but
only if someone defrosts the freezer regularly). Consider these options
very carefully, because they will make a difference.
Placement of the refrigerator is very important,
as shown at right. Room temperature, direct sunlight, and close contact
with hot appliances will make the compressor work harder. More importantly,
heat from the compressor and condensing coil must be able to escape freely,
or it will cause the same problem. Don't suffocate the refrigerator by
enclosing it tightly in cabinets or against the wall. The proper breathing
space will vary depending on the location of the coils and compressor on
each model--something important to know before the cabinets are
redesigned.
For the most environmentally sound choice, look
for the superefficient models containing nonCFC refrigerants that will
not harm the Earth's ozone layer. And don't keep that old, inefficient
fridge running day and night in the garage for those few occasions when
you need extra refreshments. (A 15-year-old refrigerator could cost $100-$150
per year.) Utilities or organizations in many communities will pick up
old refrigerators and take them to recycling centers where CFC is recovered.
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| Because most refrigerators reject heat from the bottom
and/or back, they need adequate clearance to allow sufficient airflow.
While no specific studies have been done to calculate the optimum clearance
space, one general rule-of-thumb is to double the space recommended by
manufacturers for refrigerator installation. |
Cooking Appliances
The choices here will depend on the number of
cooks, their cooking preferences, and whether or not the home is a candidate
for fuel switching. Some people prefer cooking with gas, while others favor
noncombustion appliances. Remodeling is the time to make the switch, since
running gas pipes, vents, and electrical connections will influence the
layout of the kitchen. Depending on the local gas and electric rates, energy
savings can be significant, but the cost of switching should also be considered.
Almost all modern gas ranges save energy with
electronic or thermal ignitors instead of standing pilot lights. The commercial
ranges (new and used) that are becoming very popular in residential kitchens
may not have electric ignition, so be sure to check before buying one.
Self-cleaning ovens burn grime off the interior surfaces with a long, high-temperature
cycle. While this uses extra energy, it reduces the need for caustic chemical
oven cleaners. Self-cleaning ovens also have more insulation, which reduces
energy use during normal oven operation. Beware of ovens with 400-watt
thermal ignitors that operate continuously when the oven is on.
For electric ranges, the standard coil element
is probably the best bet. High-tech ranges use halogen lamps or magnetic
induction to heat the cooking surface. These are more efficient, but costly.
Solid disk elements look better than electric coils, but they heat more
slowly and generally use more energy.
Electric convection ovens cost about 30% less
to operate than conventional electric ovens and are worth the extra investment.
They circulate air inside the oven to improve efficiency and reduce cooking
time.
Cooktops separated from ovens allow more flexibility
for cooks than ranges. Energy use shouldn't be affected, but installing
the individual units will require more resources and likely cost more money.
Microwave ovens are convenient and energy-efficient.
They use one-third as much energy as conventional ovens and generate very
little waste heat to burden the air conditioning system in the summer.
Dishwashers
Choose a dishwasher with a built-in water-heating
booster. About 80% of the energy used by dishwashers is for hot water,
so using this booster heater means the temperature setting on the main
water heater can be set at 120deg.F, instead of the 140deg.F recommended
for dishwashing. The less water used, the less energy consumed, so check
the manufacturer's data on water use and shop for models with variable
wash cycles, including energy-saving cycles. Also, select an air dry option,
which does not use the electric heater during the drying cycle (this is
a standard feature on the latest models).
The kitchen has been declared the noisiest room
in the house, and dishwashers are one of the reasons. Look for a dishwasher
that is quiet as well as energy-efficient.
Small Appliances
Small appliances don't use enough operating energy
to worry about. In fact, using a small appliance may save energy compared
to doing the same job with a big one. For example, heating a slice of pizza
in a toaster oven uses less energy than firing up the full-size oven.
Lighting
Efficient lighting starts with good design. Begin
with task lighting for countertops and other work areas, then think about
general background lighting. During the process, keep in mind how natural
and electric light can blend for the best results.
Divide task light fixtures into independently
switched task areas. For example, counter, island, range, and sink would
each have a separate switch. With ample task lighting in kitchens, general
ambient lighting may not be needed; however, if it is installed, it should
also operate from its own switch. This background lighting could be a surface-mounted
fixture, a cove light mounted on top of the cabinets, or a luminous ceiling.
Recessed overhead lights, although used extensively in kitchens for both
ambient and task lighting, can be the source of serious air infiltration
and moisture problems and should be avoided when possible (see "Recessed
Downlights," p. 14).
Fluorescent or Incandescent?
Currently, fluorescents are the most efficient
light source suitable for residential use. Since kitchen lights burn for
hours at a time, they offer ideal applications for both linear and compact
fluorescent lights. Not only do fluorescents use less energy, they also
can last 10 times longer than incandescents, making them particularly appealing
for difficult-to-reach fixtures.
Linear fluorescent lamps, commonly referred to
as "tubes," convert electricity to light with four times greater
efficiency than the typical incandescent lamp. Tubes come in a variety
of sizes. Larger ones work well for ambient lighting, while the smaller
models are perfectly suited for under-the-cabinet task lighting, for example.
Compact fluorescent lamps (CFLs) are two to three
times more efficient than incandescents. Their smaller size makes them
easier to screw into sockets normally occupied by incandescents, but sometimes
their unique shapes are not the perfect fit for fixtures. However, there
are now many choices of CFLs on the market, especially for replacing 60W
and 75W incandescents. Recently, manufacturers have introduced CFLs with
light output similar to a 150W incandescent bulb. There are also CFL fixtures
available that take pin-based compact fluorescents so there is no need
to worry about the bulb's fit. Proper fit is particularly important in
enclosed fixtures, where heat buildup can affect the lamp's performance.
Favorite spots for CFLs in the kitchen are over the sink and in suspended
and ceiling-mounted fixtures.
A fluorescent lamp needs a ballast to provide
the proper electrical input. Select electronic rather than magnetic ballasts.
They operate the lamp at a higher frequency, eliminating the flicker and
hum sometimes associated with fluorescents. Older electronic ballasts have
been known to interfere with electronic devices, such as telephones, televisions,
and computers, but current models have eliminated this problem. See if
the local electric utility can recommend any particular models.
Fluorescents once had a reputation for providing
poor-quality light. That changed roughly 10 years ago when lamps with improved
color characteristics became widely available. The color problem is easy
to avoid by paying attention to two numbers. The first is color temperature,
expressed in degrees Kelvin (K). Most people associate indoor light with
the "warm" look of incandescent lamps at 3,000K or less. Fluorescents
for indoor use should have a color temperature of not over 3,500K. The
second number is the Color Rendering Index (CRI), which indicates how accurately
the light displays colors. Always select lamps with a CRI above 80. Since
each manufacturer has a different designation for color properties, it
may be difficult to tell by looking at the packaging. However, the manufacturer's
product literature often provides the CRI and color temperature information.
Only 10% of the electricity that enters an incandescent
lamp comes out as light. The rest turns into heat, which must often be
removed with air conditioning. Because they are so inefficient, incandescents
should be used selectively for accent and task lighting, or dimming circuits
where fluorescents might be too expensive.
Although they are up to 30% more efficient than
other incandescents, halogen lamps are still less efficient than fluorescents.
Their main advantage is a crisp white light and better control of the light
beam. Halogen PAR lamps and the low voltage MR16 lamps are a good choice
when you need to direct light to a certain spot.
Lighting Controls
Good lighting controls put the right amount of
light in exactly the right place only when it is needed.
Dimmer switches reduce light output and energy
use when not set at full brightness. As a practical matter, a dimming circuit
should use an incandescent lamp. Halogen lamps can be a good choice because
they are slightly more efficient than other incandescents. Although dimmers
are available for some fluorescents, the ballasts and controls may be too
expensive for most residential budgets.
Motion sensors, also known as occupancy sensors,
are appropriate in areas such as closets and pantries, where people move
in and out but may not stay long. Incandescent lamps work well with motion
sensors. This kind of use will shorten the life of fluorescent lamps and
ballasts.
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Recessed Downlights
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| Recessed downlights are very popular in kitchens, but they can cause
problems. Typical recessed fixtures create a large hole in the ceiling
and allow a lot of air to pass from the room into the space above the ceiling.
If that ceiling is insulated, trouble could be brewing. |
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| The first problem is heat loss carried by the air escaping
from the kitchen. A second problem is a hitchhiker that goes along for
the ride. Water vapor--generated in large amounts in kitchens--flows with
the air through the recessed fixture and directly into the attic or wall
cavity, where it can condense on a cool surface, such as the roof sheathing.
This can lead to mold, mildew, and eventual structural decay. Cathedral
ceilings are especially vulnerable to the moisture problem, because they
have limited ventilation space.
To avoid these problems, consider surface-mounted fixtures, such as
track lights. When recessed fixtures must be used, always specify airtight
models that have been pressure tested for low air leakage and be certain
they are properly insulated. To ensure the best efficiency and light distribution,
install compact fluorescent fixtures.
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Windows and Skylights
Adding windows captures natural light and saves
energy. But don't go overboard. Too much natural light, especially if it's
all from the same direction, can create glare. Large expanses of glass
can also reduce thermal comfort by increasing heat gain or heat loss. So
add each window for a specific reason: to frame a view, to light a task
area, or for cross-ventilation.
The thermal performance of windows has improved
greatly over the last 20 years. Today, multiple glazings, low-emissivity
(low-e) coatings, and insulated edges combine to give windows overall insulating
values that can exceed R-4. Window efficiency is rated by U-factor, which
is the rate of heat flow (and the inverse of the R-value). A lower U-factor
means less heat transfer.
If possible, install windows on the south side
of the room. These will capture solar energy in the winter. Add overhangs
and external shading to block unwanted heat gain in the summer. If external
shading does not fit the project, look for new glazing products that block
direct solar gain without the heavily tinted coatings needed in the past.
The shading ability of a window is indicated by its solar heat gain coefficient.
The lower the number, the better. Check the National Fenestration Rating
Council (NFRC) labels on windows for the solar heat gain coefficient and
U-value. The U-value on the NFRC label is the rating for the whole window,
including the frame.
Small skylights can bring natural light to dark
interior spaces without burning a single kilowatt-hour. However, they can
also cause unwanted summer heat gain and lose warm air to the outside in
winter. To minimize the problems, keep skylights small. Four to eight square
feet may be all that's needed. In warmer climates place skylights on a
north-facing roof plane to reduce summer heat gain.
If the existing structure allows, angle the walls
of the skylight well so that they fan open into the room, allowing the
light to spread. Don't forget to insulate the area around the skylight
to at least the same R-value as the ceiling.
Whether illumination comes from a natural source
or an electric lamp, try to take full advantage of it. Light-colored paint
on the walls and ceiling will bounce light around a room. Prime locations
are in skylight wells and on surfaces used for indirect lighting. Light
colors also help to make a small room seem more spacious. Semigloss paint
adds a bit of reflectivity and durability and eases cleaning. However,
to reduce glare avoid semigloss on walls that receive direct sunlight.
Kitchens can get a bit steamy with all the cooking,
dishwashing, and gathering of people in one space. In winter, the coldest
surfaces in the kitchen are probably the windows and their frames. That's
where the water vapor floating in the air will condense. Wood, vinyl, and
fiberglass are the best frame materials for insulating value and for reducing
moisture problems from mold and mildew.
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Remodeling BluNders
- Not considering the long-term energy savings when looking at costs
- Forgetting to insulate and seal against air infiltration, especially
when cabinets and vents are installed
- or moved.
- Placing the refrigerator next to the stove or dishwasher and stuffing
it tightly in enclosed spaces
- Not taking advantage of natural daylight with high efficiency windows
- Using numerous incandescent recessed downlights
- Hiring a contractor or architect who believes energy efficiency means
sacrificing attractive design and top quality.
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Ten Common Energy Questions about
Remodeling the Kitchen
1. What's the single most important efficiency
improvement for my remodeled kitchen?
Make sure you have an efficient refrigerator.
2. What kind of lights should I specify?
Fluorescent for general lighting requirements and certain task-specific
applications like under cabinets to light counter space. Incandescent,
including halogen, for limited accent or task lighting and with dimmers
where fluorescents are not available. (For general purposes, halogens are
not much more efficient than other incandescants.)
3. I have lots of small appliances: toaster
oven, coffee maker, etc. Are they major energy users?
No. Most small appliances that are used intermittently consume relatively
small amounts of energy and sometimes are more efficient than using a larger
appliance (like an oven).
4. Is it possible to get a dishwasher that
will run quietly AND save energy?
Yes. Buy a new, "euro-style" dishwasher. Most of these units
consume far less energy than models sold only a few years ago, and they
are much quieter. You won't need to flee the kitchen every time you turn
it on.
5. I decided to keep all my old appliances
in the new kitchen. Does that mean I can't save any energy?
No. Make sure that your walls are adequately insulated and use fluorescent
lighting. If replacing windows, install new, efficient models. (There are
reversible ones for easy cleaning available).
6. I am basically just replacing the cabinets;
what can I do to save energy?
You can reduce air infiltration by carefully sealing all utility cut-throughs
and false ceilings before installing the new cabinets. Don't forget to
leave space for ventilation around the refrigerator. Also, to save resources
and money, you can simply reface the cabinet doors for an entirely new
look.
7. I am considering buying a new, larger microwave
oven. Is it less efficient than my oven and stove?
Microwave ovens will use much less energy than conventional stoves when
cooking small amounts of food. That's a very common situation, so go ahead
and buy it.
8. My old kitchen was very stuffy; what can
I do to improve ventilation?
New, quiet exhaust fans are now available that allow you to hold a normal
conversation while they work to remove moisture, odors, and gases from
the area.
9. I want to increase the size of the kitchen.
Does this mean I'll have to buy a higher capacity heating and cooling system?
Unless you are constructing a large addition, your present system will
probably work since most heaters and air conditioners are oversized. But
it is important to understand that comfort levels can change (and be improved)
during a remodel. Be sure that proper air distribution and ventilation
are considered in the new design.
10. Does cooking with gas or electricity make
a difference in energy use? I'm trying to decide if I should switch.
Cooking with gas generally uses less energy, but some gas ovens have
electric ignitors that stay on when the oven is on and should be avoided.
Whether you will save money from switching depends on the rates you pay
for electricity and gas. A gas oven uses about 0.112 therms per hour, while
a standard electric oven uses about 2 kWh. So, if your rates were, say,
8¢/kWh for electricity and 60¢/therm for gas you'd pay about 16¢
an hour for the electric oven and 7¢ per hour for the gas oven.
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Ventilation
If a kitchen is properly ventilated, moisture
as well as odors and carbon monoxide vapors from combustion appliances
can be controlled. Always install a range hood with at least a 150-cubic-feet-per-minute
fan that exhausts to the outdoors. Avoid recirculating hoods because they
do nothing to remove moisture.
Most range hoods are too noisy, so people don't
use them as much as they should. One solution to the noise problem is a
remote-mounted fan installed away from the kitchen and connected to the
range hood by a duct 6 to 8 inches in diameter. Go ahead and pay more for
a quiet fan. It will be used more because people will not have to leave
the room to have a conversation.
Range hoods mounted above the cooking surface
are effective because they work with the momentum of the vapors as they
rise naturally from the cooking surface. Downdraft fans must overpower
this natural momentum with a fan two or three times larger than is necessary
in an overhead hood.
In "tight" houses or where multiple
or larger exhaust fans are used, suction can cause flue gases to spill
from combustion devices, such as gas water heaters, furnaces, and wood
stoves. If the house has combustion appliances, be sure that they have
an adequate air supply.
Insulation and Air Sealing
While working on the ventilation system, remember
to seal the ducts and the openings where they penetrate walls. If old vents
are not going to be used in the renovation, be sure they are sealed off
and the area is insulated. Often flex duct is used to extend existing duct
runs to a new register. It's important that there are no bends in the ducts
that will inhibit air flow and that the joints are secured with airtight
mechanical fasteners.
When the remodeling project tears into the building's
structure, a whole new set of energy-saving opportunities arises. This
is the perfect time to tighten up air leakage passageways that cause discomfort
and contribute to high heating and cooling costs. While the walls are open,
seal all the gaps around pipes and wires. Air leaks through gaps like these
can be responsible for 30% of the heat loss in a typical older home; the
kitchen, with all its plumbing, electrical, and gas penetrations, is a
major source of that leakage. Don't forget the space behind cabinets and
above false ceilings, which are common corridors for air flow to and from
the outside.
Next, fill the walls, ceilings, and floors with
as much insulating value as is economically feasible. The local utility
will know what level is recommended for the area. An R-value may be printed
on the insulation bag, but proper installation is required to actually
achieve that value. Demand a high-quality job. Batt insulation should fill
every nook and cranny without compressing the material. Loose-fill and
dense-pack insulation can be blown into areas around obstructions. With
both systems, the skill of the installer is critical. Use expanding foam
to seal and insulate areas too small for fibrous insulation.
Water
In most households, heating water ranks second
only to space conditioning on the list of big energy users. Much of that
hot water goes to the kitchen for cleaning and dishwashing.
As a first step to save energy be sure the thermostat
on your water heater is not set above 120deg.F and that the tank is wrapped
with an insulating jacket. Insulating the hot water pipes will save even
more.
All new faucets should restrict water flow to
no more than 2.5 gallons per minute. If a new faucet is not in the plan,
a replacement aerator will reduce water use.
On-demand water heating systems installed in
the kitchen eliminate the long wait for water to get hot as much of it
pours down the drain. Until recently, most of these systems had drawbacks
because of fluctuating temperatures, limited capacity and questionable
energy savings. However, new demand systems, which simply accelerate the
flow of water from the hot water tank and force standing water in the pipes
back to the tank, provide convenience and save water and energy. Don't
confuse these with constant recirculation systems, which increase energy
use.
Household Recycling
When most existing kitchens were designed, little
thought was given to trash removal beyond garbage disposals and trash compactors.
Now that household waste recycling is available in most communities, kitchens
need to accommodate sorting and storage of an increasing number of materials.
The kitchen is the logical place for a recycling center.
Recycling systems can be as individual as people
and their kitchens. Any retailer with a good selection of storage supplies
should be able to offer the makings of a suitable system. Here are two
guiding principles:
- Keep it flexible. The recycling industry is growing and changing. Local
recyclers may start accepting new materials or change the way materials
are separated. A rigid storage system may not adapt to changes.
- Keep it simple. No one likes to deal with trash, so reduce handling
to a minimum. Most people like a system that allows sorting, storage, and
transportation all in the same container.

Green Building Materials
Throughout the project choose products and materials
that are friendly to the environment. Hundreds of materials with recycled
content are now available. They use less energy for reprocessing than new
materials use for extraction and primary processing. A few examples are
ceramic tiles made from glass bottles, floor boards resawn from old barn
beams, and cellulose insulation that gives a second life to newspapers.
Other categories of green materials are wood
from trees that are grown in sustainably managed forests and nontoxic products
for sealing, finishing, etc. A few large cities have stores that specialize
in these products. Several sources of information about sustainable products
are listed under "Resources."
Resources
Consumer Guide to Home Energy Savings, American
Council for an Energy-Efficient Economy, 2140 Shattuck Ave., Suite 202,
Berkeley, CA 94704. Tel:(510)549-9914; Fax:(510)549-9984. (Includes guide
to efficient new appliances)
Environmental Building News, West River
Communications Inc., RR 1 Box 161, Brattleboro, VT 05301 Tel:(802)257-7300;
Fax:(802)257-7304. (Bimonthly newsletter on sustainable building)
Lighting Research Center, Rensselaer Polytechnic
Institute, Troy, NY 12180-3590. Tel:(518)276-8716; Fax:(518)276-2999. (Books,
including Lighting Pattern Book for Homes, and technical reports
on energy-efficient lighting)
The Smart Kitchen, and Choose to Reuse,
Nikki and David Goldbeck, Ceres Press, P.O. Box 87, Woodstock, NY 12498.
Tel/Fax:(914) 679-5573.
Iris Communications, Inc., 258 East 10th Ave.,
Suite E, Eugene, OR 97401. Tel:(800)346-0104; Fax:(503)484-1645. (Books,
videos, product directories and databases on energy efficient and sustainable
building materials, free catalog)
Center for Resourceful Building Technology, PO
Box 100, Missoula, MT 59806. Tel:(406)549-7678; Fax:(406)549-4100. (Sustainable
building consulting, product guides)
| Bruce Sullivan is president of Iris Communications,
Inc. and editor of Energy Source Builder. |
| This article is part of a series on energy-efficient
remodeling, which is being funded by the Environmental Protection Agency
and the Department of Energy. |
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