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aving Money
by Saving
in Manufactured Homes
Low cost energy-saving tips, techniques and recommendations
designed especially for manufactured (mobile) homes
aving Money
by Saving
in Manufactured Homes
Low cost energy-saving tips, techniques and recommendations
designed especially for manufactured homes
Manufactured Housing Research Alliance
2109 Broadway, Suite 200
New York, New York 10023
Available to the public from:
U.S. Department of Housing and Urban Development
Office of Housing and Development and Research
451 7th Street, SW
Washington, DC 20410
Web site:
This project was made possible through funding from the US Department of Housing and
Urban Development (HUD). Michael Blanford and David Engel with HUD recognized the
need for this guide and provided invaluable leadership and editorial guidance.
This publication was prepared by the Manufactured Housing Research Alliance with the
assistance of The Levy Partnership, Inc. and D&R International, Ltd. Emanuel Levy,
Jordan Dentz, Sandra Ho and Chris O'Neal (The Levy Partnership, Inc.) and Chris Rivera
(D&R International) were principally responsible for writing the guide and coordinating
the contributions of other manufactured home experts.
This publication would not have been possible without the valuable advice and input of
many people. Special thanks go to Alex Wilson, Mark Peipkorn and Julia Jandrisits of
Building Green, Inc. Major contributions were also made by weatherization professionals
who are on the front lines of improving energy efficiency of existing homes in America,
including Bill Beachy and Anthony Cox (New River Center for Energy Research and
Training), Bob Scott (West Virginia Weatherization Assistance Program) and Cal Steiner
(North Dakota Weatherization Assistance Program). Thanks also to those who reviewed
and commented on drafts of this guide, including: Elizabeth Cocke, Victor Ferrante and
Rick Mendlen (HUD), Brian Ng and Chandler Von Schrader (Environmental Protection
Agency), Larry Boyce (Nordyne, Inc.), Gerald Colburn (Rheem Water Heaters), Francis
Conlin (ComfortWorks), Robert Garcia (Fleetwood Enterprises, Inc.), Omar Gaudette,
Steven C. Church and Julie A. White (Whirlpool Corp.), Mike Kinard (Kinro, Inc.), Keith
Ledet (GE Consumer Products), Michael McKitrick (Alcan Composites, Inc.), Joe Neer (ITW
Foamseal), Mark Nunn (Manufactured Housing Institute), Chris Parish (Parrish Manor),
Kathy Presciano, (GE Lighting), Dwight Schuler (Owens Corning, Inc.), Terry Small and
Doug Hayes (Mortex Products, Inc.), Jim Welz (Philips Products) and Alan Zimmerman
(York International Corp.).
Research was performed under contract with the Office of Policy Development and Research,
US Department of Housing and Urban Development.
NOTICE: This booklet was prepared by an agency of the United States government.
Neither the United States government nor any agency thereof, nor any of their employees, nor the authors, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information,
apparatus, product, or process disclosed, or represents that its use would not infringe
privately owned rights. Reference herein to any specific commercial product, process, or
service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do
not necessarily state or reflect those of the United States government or any agency
Why older manufactured homes are good candidates
for energy efficiency retrofits:
All homes experience wear and tear. Whether your home is five or fifty years
old, chances are good that it can benefit from cost-effective measures to
improve its energy efficiency. Wind and vibrations can loosen up a tight home,
increasing air leakage; windows may no longer close tightly, and ductwork can
spring leaks, wasting huge amounts of heating or cooling energy. Furnaces, air
conditioners, and water heaters that have been running for years gradually lose
efficiency, especially if regular cleaning and maintenance hasn't been done. All
these things add up!
Technologies change. While your manufactured home may have been built to
the energy standards of the time, dramatic progress has been made over the
past couple decades with high-efficiency mechanical equipment, insulation,
windows, and so forth. Our understanding of how to retrofit manufactured
homes for energy savings has also improved through years of experience—as
has our knowledge of how to prevent moisture problems.
Energy costs are going up. Whether you use electricity, natural gas, propane, or
oil, many experts believe that prices will continue to rise. Improving your home
now guards against future increases, and rolls back the costs you're paying
today. Protection from much higher costs in the future may be particularly
important if you're nearing retirement and will be on a fixed income.
Why save energy? Five good reasons why an energy
retrofit makes sense:
Lower energy and homeownership costs
Protection against future increases in energy costs
Improved comfort—fewer drafts, more comfortable temperatures, less temperature fluctuation floor-to-ceiling and from room to room
Increased resale value—a home with lower operating costs is worth more
Environmental stewardship—saving energy reduces the burning of fossil fuels
that contributes to global warming, acid rain, smog and other kinds of pollution
How to tell if you can benefit from improving your
home's energy performance.
Your home is a good candidate for upgrade if:
You have significantly higher utility bills than neighbors with similar homes and
Your home was built before 1976 and hasn't been significantly improved or
Your heating, cooling, or water heating equipment breaks down a lot
You feel drafts inside on windy days
The air near the floor is significantly cooler than the air near the ceiling
You have to wait a long time for hot water, and water cools off quickly between
You have to set the thermostat below 70° to stay cool in the summer
You have trouble keeping your home warm in winter
There are large fluctuations in your utility bills from month to month
The HUD Code
In 1976 national standards for
manufactured homes went into
effect establishing insulation
and window requirements. In
1994 these standards were
The energy efficiency retrofit ideas described in this guide have been selected because
they provide excellent energy savings. In general, more expensive techniques result in
greater savings, but some inexpensive techniques described here can also lower your
energy bills substantially. This guide will help you choose the most cost-effective ways
to reduce energy use that fit your budget and your home's characteristics and location.
There are many ways to save energy and reduce costs; the techniques covered here provide exceptional value for manufactured home owners and will pay for themselves relatively quickly through energy savings.
The retrofit techniques are divided into ten categories shown in Table 2. Each category
contains a number of related techniques. In general, the top item(s) in each category are
easier to complete and cost less. The techniques in the latter categories typically require
greater skill and cost more, but they also provide greater energy savings.
Table 2 also indicates the approximate cost and skill level of each technique and the climate in which that technique is most appropriate. You’re in a colder climate if your energy bills are highest in winter, and you’re in a hotter climate if your power bills are higher
in summer. An explanation of the symbols used in the table and throughout the guide is
provided below.
Table 1. Key to symbols
describing each energy
savings technique
Two additional symbols explained below are designed to draw your attention to helpful
Energy Savings
Approximate Cost
This technique provides exceptional energy savings relative to its
No cost
Cost less than $100
Cost between $100 and $500
Cost over $500
No skill required; for example, changing a light bulb or a filter.
Ability to use basic tools and follow directions; for example,
installing water heater insulation wrap.
Must be very handy; for example, fabricating and installing a simple storm window.
Requiring professional skills and equipment; for example, installing
insulation in the walls.
! Especially important information or cautions about things to avoid or risks of
certain techniques.
Z Tip for additional energy savings or other benefits.
The next page contains a list of the energy saving ideas described in the guide. The techniques will provide the greatest savings in the climate indicated.
Costs are rough approximations and will vary depending on the size and condition of your home as well as the specific products and techniques chosen to implement the energy saving retrofit measure. For do-it-yourself measures
this is the cost of materials only. If the technique is listed as PRO (requiring professional assistance) then it is the fee
charged by the contractor.
A rough estimate of the skill level required to install a given measure.
• Clean or replace the furnace filter ★
• Have a pro maintain and tune up the furnace ★
FREE or $
• Replace the furnace
• Have a pro perform seasonal maintenance ★
FREE or $
• Replace the air conditioning system
• Technique
1. Improve heating system performance
2. Improve cooling system performance
• Clean or replace the air filter ★
• Clean the condensing cooling coils
3. Eliminate leaks in ducts
• Seal supply duct connections to boots and registers ★ All
Seal duct ends ★
Make sure all registers are fully open ★
Seal and insulate crossover duct and connections ★
Inspect and repair ducts from under the home ★
• Replace incandescent light bulbs with CFLs ★
• Install energy-saving controls on exterior lights
• Clean fixtures
• Use low-wattage light bulbs
FREE or $
• Install a reflective roof coating
8. Improve window performance
• Install interior storm windows ★
• Patch/replace torn or missing bottom board ★
• Seal gaps and cracks in the walls, floor and ceiling
• Cover window air conditioners
• Seal leaky windows
• Fix poorly fitting exterior doors
• Seal beneath the furnace
4. Improve lighting efficiency
5. Improve refrigerator performance
• Properly operate your existing refrigerator
• Buy a new refrigerator
6. Improve water heater performance
• Insulate the tank ★
• Insulate water pipes leading from the tank ★
• Lower the water heater thermostat ★
• Clean the tank
• Install low flow showerheads and faucet aerators
• Replace your water heater
7. Reduce solar gain
• Install sun screens
• Install exterior awnings
• Apply reflective window film
• Use interior shades to block sunlight
• Install plastic disposable window insulating kits
9. Eliminate leaks in the walls, floor and ceiling
10. Insulate walls, floor and ceiling
• Add insulation to the floor
• Add insulation to the roof
• Add insulation to sidewalls
Table 2. Energy saving techniques described in this guide
The following table contains a list of programs that offer financial and other assistance.
Table 3. Getting help—a list of
programs that offer financial
and other assistance
How to Contact
Assistance Programs
Yellow Pages under "weatherization"
State energy offices
Access state agency directory
Varies by state—some offer technical
assistance and/or rebates or other
incentives for energy efficiency
Home Performance
Refer you to a qualified contractor.
Contact your power company
Some utilities offer rebates or other
incentives for energy efficiency
Municipal programs
Yellow Pages under city, country, or town
Available in some areas.
What they can do
Free home weatherization for qualified applicants; often have long waiting lists.
In the next section of the guide, each technique is described in detail, including the following information:
How to tell if the technique makes sense for you—by describing the situations
where the technique will create the most benefit.
The level of skill required—whether the project is suitable for a homeowner to
perform (and if so, the level of skill required), or if it requires professional assistance.
Enough detail for you to carry out a simple do-it-yourself (DIY) technique—or for
more complex projects, a basic description of what a professional contractor
will do and where to get more information.
Approximate costs of doing the project.
Also included is a list of common-sense, low-cost or no-cost lifestyle tips that you can
implement today to lower your energy bills. A list of resources for additional information
is provided at the end of the guide.
Selecting a pro
When selecting a professional contractor to perform any work on your manufactured home, be sure to choose one who has experience
with the specialized techniques and construction characteristics of manufactured homes. Your State's Weatherization Assistance
Program (see Table 3 on Page 4) may be able to direct you to a list of potential contractors. You can also locate contractors through your
electric utility, manufactured home retailer, and the yellow pages or by talking to neighbors. Always choose licensed contractors-and
check their references. Select a contractor with a track record of satisfied customers and plenty of experience with your type of project.
Questions to ask a prospective contractor
Ask for a written estimate of the work based on a set of plans and/or written specifications. If you are comparing estimates, be sure
they are based on the same specifications and scope of work. Beware of an exceptionally low price. Find out whether the contractor
uses a detailed, written contract that protects both of you and that complies with all laws. The contract should spell out the work that
will and will not be performed and provide a fair payment schedule. Ask the contractor if they offer a warranty, and if so, what kind and
for how long. Professional contractors should carry insurance that protects you from claims arising from property damage or jobsite
injuries. Ask for a copy of the contractor's insurance certificate.
Double check your prospective contractor's qualifications
Check with your local or state office of consumer protection and the local Better Business Bureau. Ask if they have had any complaints
about the contractor and if so, whether they were resolved satisfactorily. Check with your state's licensing agency and the state and
local building inspectors to see if they have received any complaints about the contractor and to verify that they have the appropriate
licenses and registrations.
Most manufactured home heating systems have two main
parts: a furnace that heats air, and ducts that channel the
heated air throughout the home. This section discusses the
furnace; turn to page 10 for techniques to improve duct system efficiency. The furnace—often located inside a closet—
generates heat by burning natural gas, propane, or oil, or by
using electricity. Heated air from the furnace is then blown
through ducts (which may be under the floor or in the attic),
and finally through registers or grates into various rooms.
Crossover duct
Main trunk duct
Fresh air
Cooling coil
Fan (blower)
Inside a typical electric furnace closet
Branch duct
A heating system that operates efficiently reduces
Typical floor duct system
energy use while providing
the necessary comfort. High efficiency is important,
particularly in colder climates. There are several components in a manufactured home heating system that
need to be properly maintained. Following the tips in
this guide will keep your heating system running
smoothly and efficiently, and increase its lifespan.
If you answer YES to any of these questions, heating
system maintenance is especially important for your home:
Are you in a colder climate?
Do you find it difficult to keep your home warm in the winter?
Does your heating system experience frequent breakdowns?
Is one part of the house much colder than others?
For combustion furnaces only, can you see soot near the roof jack (chimney)
cap? This may indicate improper flame adjustment.
There are some simple things you can do yourself to make sure your heating system
operates smoothly; other actions require the help of a professional. For older heating
systems, replacement may be the best option.
Clean or replace the furnace filter
(FREE or $, low skill)
Filters help keep the furnace's heat exchanger and blower clean, by removing dust from
your home's air. Furnace filters are generally made of fiberglass or plastic fibers, or
porous foam that allows air to pass through. Return air from the house is filtered as it is
pulled through the filter.
Dirty filters reduce the efficiency of your furnace by restricting airflow. Some filters are
designed to be vacuumed or washed, but most are disposable and need to be replaced
when they become clogged. Replacement is an easy task that most homeowners can do
Filters may be located in a number of places in a furnace, depending on the make and
model. The accompanying diagram shows some of the more common locations.
! When installing the new filter, make sure the air-flow arrow
on the filter points towards the
furnace fan.
! It is especially important to
clean pleated filters at least
monthly. These filters are more
efficient at removing dust, so
they get dirty more quickly than
conventional filters, which can
lead to less efficient operation
and shorter furnace life.
Return air
While electric furnaces and heat pumps always
have air filters, some gas and oil furnaces do
not. If you have a furnace without an air filter,
you should install one. Check with a heating
system technician if you are unsure how to add
a filter.
filter locations
During the heating season check the air filter
every month, and clean or replace it if it
appears dirty. Filters cost at most a few dollars
and are available at most hardware stores and
home centers.
(if air conditioned)
Filter(s) may
be clipped
to the back
of the
door if it
has air
Dirty furnace filter
Heat exchanger
Have a professional maintain and
tune up the furnace
($, PRO)
Main duct
Possible furnace filter locations
A professional service technician should be brought in periodically to
check thermostat operation; clean, adjust, and lubricate moving parts;
tighten electrical connections and inspect electrical parts; check fuel
connections; test the combustion efficiency; and inspect controls and
the starting function. How often you should have professional service
depends on how much your heating system operates: for homes in colder regions, annual service is recommended; heating systems in warm
regions should be serviced every 2 to 3 years; in hotter regions, every 3
to 5 years is enough.
Replace the furnace
($$$, PRO)
Furnaces are expensive, but are candidates for replacement if they're worn out, inefficient, or bigger than your house needs. (An oversized furnace can use a lot more power
or fuel than a properly-sized one.) Some indicators that you will be better off with a new
furnace are:
! Unvented kerosene and gas
heaters should be avoided.
Kerosene heaters can be a fire
hazard, and both kerosene and
gas heaters introduce water
vapor to the home (a byproduct
of combustion). If not operating
properly, unvented kerosene and
gas heaters can release dangerous indoor air pollutants.
The furnace is over 25 years old.
The furnace combustion efficiency, as tested by a service technician, is lower
than 65 percent.
The heat exchanger is cracked, which you or a service technician may notice
during cleaning or inspection.
Repair or modification would cost more than half as much as replacement
The furnace does not operate well and can't be fixed.
You've sealed your home's walls, floor, ceiling (page 23) and ducts (page 10),
installed storm windows (page 21), and performed heating system maintenance—and you still can't keep your home warm.
The furnace has a standing pilot light.
A heating system technician can help you evaluate whether a new furnace is appropriate. As part of this evaluation they should measure the efficiency of the existing furnace.
Z Check with your local electric
utility about incentives for
installing a heat pump.
If you have an electric furnace and have high heating bills, then consider adding a heat
pump. A heat pump combines heating and cooling functions and, in the heating mode,
is far more efficient than electric-resistance heat. The more common air-source heat
pumps are appropriate for all but the hottest and coldest climates.
Choose only a sealed combustion furnace specifically designed for use in a manufactured home. Sealed combustion furnaces draw in the air needed for combustion directly
from the outside, not from the home itself.
There are two broad categories of air conditioners: individual room
units (the kind usually mounted in windows), and central systems.
Central air conditioners can be further categorized into split systems,
in which the compressor/condenser is located outdoors, while the
evaporator is inside the home; and packaged systems, in which the
entire unit sits outside with ducts carrying air to and from the house.
In either type of central system, chilled air is blown through ducts
(located either under the floor or in the attic), and into the living
space through registers or grates (see diagrams).
Furnace with
evaporator coils
An efficiently operating cooling system is critical to decreased energy use and increased comfort, particularly in warm climates. A wellmaintained air conditioning system will use 15% to 40% less energy
than a neglected one. There are several components in cooling systems that need to be properly maintained. Following the tips in this
brochure will extend the life of your cooling system, and keep it running smoothly and efficiently.
Split system air conditioner
Return register
Supply register
If you have central air conditioning or a heat pump and answer YES to
any of these questions, cooling system maintenance is especially
important for your home:
Are you in a hot climate?
Do you find it difficult to keep your home cool in summer?
Does your cooling system experience frequent breakdowns?
Packaged condenser/
evaporator unit
Packaged system air conditioner
There are some simple things you can do to make sure your cooling system operates
smoothly; other actions require the assistance of a professional. With older and inefficient cooling systems, replacement is often the best option.
Clean or replace the air filter
( FREE or $, low skill)
Air conditioners will have an air filter to prevent dirt from building up on the cooling
coils. Examine your unit's filter once a month during the cooling season, and clean or
replace it when it appears dirty (which can indicate clogging). This alone can reduce your
cooling energy use by 5% to 15%. Many filters are designed to be cleaned, but still may
need to be replaced occasionally; this is an easy and inexpensive task that most homeowners can do themselves. Filters in room air conditioners are usually behind the front
panel. Most split-system central air conditioners use the furnace's air filter (see page 5,
Clean or replace the furnace filter). In packaged systems, the filter is generally found in
the main "return-air" register. The system’s user’s manual should help you locate it.
Clean the condensing cooling coils
(FREE, medium skill)
Clean the condenser annually by following these simple steps:
Turn off the system at the thermostat, if possible, or turn the thermostat
up to a setting that will not switch on the air conditioner. Also, turn off the
power to the outdoor unit at the main breaker panel or at the disconnect
located next to the outdoor unit.
2. Clean any loose debris from around the unit and clean it with gentle household
soap and water.
! If you have a packaged system as described on page 7,
check the duct damper and if
necessary, repair or replace it. Air
conditioning systems that share
ductwork with a furnace must
have a damper in the duct. It prevents cool air from entering the
furnace cabinet in summer, and
warm air from escaping to the air
conditioner in winter. A missing
or malfunctioning damper can
waste tremendous amounts of
energy and lead to corrosion of
the furnace.
3. Allow the outdoor unit to completely dry before turning on the power at the
main breaker panel. After the main power has been restored, turn on the system
at the thermostat or set the thermostat for normal operation.
Have a professional perform seasonal maintenance
and tune-up of central air conditioning systems
($, PRO)
Air conditioner adjustments and repairs should be done by professionals. A professional
service technician should clean evaporator and condenser coils, check refrigerant pressures, and adjust and lubricate moving parts. How often you need professional maintenance depends on how much your cooling system operates: for homes in hotter regions
(where the air conditioner operates eight or more months per year), annual service is
recommended; cooling systems in warm regions (where the air conditioner operates five
to eight months per year) should be serviced every 2 to 3 years; in colder regions (where
the air conditioner operates less than five months per year), every 3 to 5 years is usually
Replace the air conditioning system
($$$, PRO)
Z Bigger is not always better
when it comes to your air conditioner. For starters, oversized
equipment can be less effective
at dehumidifying your house. Not
only can this lead to moisture
problems in a home, but the
higher humidity may result in you
keeping the thermostat lower to
achieve the same comfort level—
increasing your energy use. An
oversized unit also cycles on and
off more frequently, which
increases wear and tear, shortens the service life, increases the
frequency of repairs, and reduces
efficiency. Plus, it costs more to
purchase oversized equipment in
the first place. If purchasing a
new air conditioner, cooling
loads should be carefully calculated by your equipment supplier.
In some situations it will make sense to replace an older air conditioner with a new,
high-efficiency unit. Air conditioner replacement should be considered if the existing
unit is worn out, inefficient, or significantly oversized.
Z If you live in a hot, dry cli-
A cooling system technician can help you evaluate whether a new air conditioning system is appropriate.
mate, such as the Southwest, an
evaporative cooler (swamp cooler) may be a good alternative to a
refrigerant-cycle air conditioner.
They use considerably less energy than standard air conditioners. Check with a local air conditioning contractor to find out if
such a system might make sense
for your home.
Repairing an existing air conditioner may seem to be the least expensive option, but it
may cost more in the long run. Paying for repairs on an older, inefficient system may
simply prolong the inevitable need for replacement. Installing a new, energy-efficient
system may be much more cost-effective.
Air conditioner replacement makes sense if:
The air conditioner is over 10 years old.
The air conditioner efficiency (SEER or EER) is below 7 or 8.
Repairs or modifications of an existing unit will cost more than half as much as
a replacement.
The unit does not operate properly and can't be fixed.
You've sealed your home's walls, floor, ceiling (page 23) and ducts (page 10),
installed storm windows (page 21), and performed cooling system maintenance,
but you still can't keep your home cool.
Use the EnergyGuide Label to compare efficiencies; and pay special attention to
ENERGY STAR labeled units, which meet
stricter efficiency standards.
If you are going to replace your central air
conditioner and you have electric heat in
your home, consider replacing the air conditioner with a heat pump. A heat pump
combines heating and cooling functions
and, in the heating mode, is far more efficient than electric-resistance heat. The
more common air-source heat pumps are appropriate for all but the coldest and hottest
Dispose of old air conditioners properly. Make sure that they aren't returned to service,
and that the refrigerant is properly captured for responsible disposal. Contact your local
municipal solid waste agency to make arrangements for disposal.
Other techniques to reduce air conditioner energy cost
(FREE to $, low skill)
Here are a few additional steps you can take to reduce your cooling energy use:
Supplement your air conditioner with fans. The air movement
will make you feel cooler and allow you to raise the thermostat,
reducing air conditioner energy use. Turn off fans, including
ceiling fans, when you're not in room—leaving them on wastes
energy and actually adds heat (from the motor).
2. Nighttime ventilation is another low-cost cooling strategy. If the temperature
and humidity drops after the sun goes down, open the windows to exhaust
indoor air and pull cool outdoor air into the house.
3. Sunlight on the exterior portion of your
air conditioner (either room units or central system compressor) will reduce its
efficiency. Shade the outside components of a central system, and place
room units on the north and/or east side
of the house. Be sure not to restrict airflow around the unit, however.
Shading an outdoor compressor can improve
energy efficiency
Most manufactured homes have forced-air heating systems. Air from the home is forced
through the furnace, where it is warmed by a hot metal heat exchanger or electric heating coils. The warm air is then blown through a system of ducts, and out into each room
through registers. In most homes with central air conditioning, the same ducts are used
for delivering chilled air during the summer.
The ducts may be in the floor (most common) or in the ceiling (usually only in hotter climates). Typically, each section of a manufactured home has a main "trunk" duct running
its length. Multi-section homes (such as double-wide units) usually have crossover ducts
that connect the main trunk ducts. With ceiling-duct systems the crossover is in the attic
and usually inaccessible. In floor-duct systems the crossover is beneath the home, and
accessible from the crawlspace (see diagrams).
Each section has
one graduated trunk
running down the
center of the belly
Registers are located
above supply boots
which connect directly
to the main trunks
Crossover duct connects
trunks in multisection
Leaky ducts are common
in older manufactured
homes and can dramatically increase heating and
cooling bills. It is not
uncommon for an older
duct system to lose 20% of
the heated or chilled air to
the outside. If your annual
heating and cooling bill is
$2,000 and your ducts are
leaky, you could be spending $400 every year to
heat and cool the outdoors.
Crossover duct connects
two attic plenum boxes in
multisection homes
Branches run
directly to diffusers
or divide into
smaller branches at
junction boxes
May have branches
Typical floor duct system
in ceiling
flexible duct
connects to
plenum box in
Typical attic duct system
Compared to other energy retrofit measures
in a typical manufactured home, sealing the
ductwork has one of the largest payoffs relative to its cost. You'll save on your heating
and cooling bills, enjoy increased comfort,
and reduce the risk of moisture problems.
Branch duct
Main duct
Common duct system leakage locations
Almost all homes can benefit from duct sealing. If you answer YES to any of these questions, your home may be especially in need of duct sealing:
Was your home built before 2000?
Is the heating and cooling air distribution in your home uneven—that is, do
some rooms get a lot of air from the registers, while others don’t get enough?
Is it difficult to heat or cool your home, even after having performed heating and
air conditioning system maintenance?
Does a visual inspection reveal a deteriorated crossover duct (see below)?
Seal the largest leaks first. Duct sealing doesn't require a lot of skill or expensive materials, but you will need time and some dexterity to get at hard-to-reach places. Here's a
list of common duct leakage sites, followed by repair suggestions:
Seal supply duct connections to boots, and registers
($, medium skill)
Supply ducts can be inspected from inside the home. First remove the
registers. You can then inspect the ducts using a mirror and flashlight
(see figure). By placing a utility light in one register and looking toward it
with a mirror from the next register, you can inspect for leaks and
obstructions between those two registers. The main areas to focus on are
connections from the main trunk duct to
the supply boots that connect to the
Sealing around a register with duct
registers. Other important sites are connections to the branch ducts, to the furnace, and to the crossover ducts. Other types of systems that don't use main trunk ducts may require variaInspecting the duct with a hand-held
tions on this inspection method.
To seal connections from supply boots to registers, follow these steps:
Step 1. Turn off the furnace fan and remove the register grille (there
is usually a screw at each end)
Step 2. Clean the duct surfaces (see the box Duct sealing materials
on page 13)
Step 3. Inspect with a mirror and/or feel the joint between the boot
and duct for gaps and tabs that may not be folded tightly
against the duct
Inside the main duct
Sealing around a register with duct
mastic —view from inside the duct
Step 4. Fold down any loose tabs and apply reinforcing mesh tape
to the corners where the boot meets the duct
Step 5. Apply mastic (see the box Duct sealing materials on page
Step 6. Replace the register grille.
Seal duct ends
($, low skill)
Last register
on duct
To furnace
Plastic bag stuffed
with insulation
Sealing the duct end with a plastic bag
Main duct below
Boot sealed with mesh tape and
The ends of ducts are often major leakage
sites. These can be sealed from the inside of
the home by filling a durable plastic garbage
bag with fiberglass insulation and inserting it
into the duct from the last register at each end
of the duct run. Insert the bag and push it in
the direction away from the furnace (see diagram). Apply expanding foam sealant to the
area around the bag for an even tighter seal.
Make sure all registers are fully open
(FREE, low skill)
Blocking air from flowing out of the registers will cause
the heating and cooling system to be less efficient
because it restricts airflow and puts more pressure on
leaks. Make sure registers that have moveable louvers
are kept in the open position or remove the louvers
entirely. Also make sure registers are not covered by
rugs or furniture.
Floor register with louvers closed
Seal and insulate crossover duct and connections
($, high skill)
Metal collar
Pay particular attention to the crossover duct in multi-section homes. One
indicator of a crossover duct leak is if the side of your home where the
furnace is located gets a lot more air from the heating and cooling system
than the other side. In this case, much of the air going to the second side
may be leaking out of the crossover duct into the crawlspace.
Crossover ducts are often insulated flexduct—inner and outer wire-reinforced plastic tubes with fiberglass insulation sandwiched between. The
flexduct connects to a metal collar, which in turn connects to the main
trunk duct. Both connections should be sealed.
When inspecting the crossover duct make sure it is firmly connected to
the home's rigid duct at both ends, and that there are no gaps, tears or
The crossover duct connection must be tightly sealed other openings in it. The crossover duct should be supported off the
ground with strapping or blocks. Inspect the crossover duct while the furnace fan is running; feel for air leaking out at all the connections, at each end of the
duct, and at any patches.
If the flexduct connection is loose or leaky, re-do the connection by following these
Step 1. Make sure the collar is screwed to the main trunk duct with at least three
screws to prevent it from
moving or rotating.
Step 2. Seal the collar to the main
trunk duct with duct mastic
or foil tape.
Step 3. Apply a ring of duct mastic or
putty tape around the collar,
and tighten the flexduct's
inner lining against this
sealant. Use a long plastic
cable tie as a permanent
Fastening the inner lining of the crossover duct to the
Step 4. Seal the inner lining of the flexduct to the collar with duct mastic or aluminum tape.
Step 5. Pull the flexduct's insulation up over the collar, and tape it to the underside
of the trunk duct.
Step 6. Tighten the outer layer of the flexduct over the collar and use another cable
tie to fix it in place.
! Duct tape can be used to
hold things together while you
create a permanent seal, but
standard duct tape should not
be relied upon for a long-lasting
Step 7. Install three pan-head screws just under the cable tie so the heads of the
screws clamp down on the tie.
Sometimes old ducts are torn or deteriorated. Replace them with new flexduct—preferably with at least R-8 insulation. When replacing a crossover duct, keep it straight and
use the minimum length necessary.
Inspect and repair ducts from under the home
($, high skill)
At connections where branch ducts meet the main duct, holes must be sealed from
underneath the home. You might have to cut openings in the bottom board to access the
ducts. (Don't attempt this unless you're prepared to seal the bottom board back up
when you're done!) Working under the home can be difficult and hazardous: wear goggles, gloves, long-sleeved shirts and other protective gear. To locate joints in the duct
system, look inside the house for registers that are offset from the main duct. Using
exterior walls and windows as reference points, measure to the place where the ducts
meet; then use those measurements in the crawl space to determine just where to cut
through the bottom board. Seal these joints with duct mastic, then repair any penetrations through the bottom board. (See Patch/replace torn or missing bottom board on
page 23.)
Seal beneath the furnace
($ materials, high skill to PRO)
This is the area in the duct system with the highest air pressure, so it's the most important place to seal. A metal box, or plenum, typically connects the furnace to the main
duct. The seams between the furnace and the plenum, and between the plenum and the
main duct, should be carefully sealed.
! Whenever working with a
furnace, especially an electric furnace, turn off the emergency
power switch first.
You can usually access the plenum from underneath the home, following these steps:
Step 1. Cut open the bottom board beneath the furnace and push aside the insulation.
Step 2. Cut an 8- to 10-inch square or rectangular temporary access hatch in the
bottom of the duct directly under the furnace—but only cut three sides of
the hole, leaving a flap. Through this temporary hatch, you can see the furnace-to-duct connection and can seal any leaks with duct mastic and fiberglass reinforcing mesh tape. The cut metal will have sharp edges. Line the
edges of the hole temporarily with duct tape to prevent injury.
Step 3. Seal the temporary access hatch that you cut into the duct
using duct mastic and
fiberglass tape,
Duct sealing materials
replace the insulation
Do not use duct tape. Before long, the adhesive will
and patch the bottom
fail and the tape will fall off. Recommended materials
board. (See Patch/
replace torn or miss• Silicone caulk—excellent for sealing small holes
ing bottom board on
and narrow cracks; it is widely available at home
page 23).
• Aluminum-foil-faced butyl tape (available from
heating and cooling wholesalers)—good for large
holes and cracks, especially in corners. If possible,
install tape on the inside of ducts, because air
pressure may eventually push it off if it's on the
outside. Clean and dry surfaces well and tightly
stretch the tape over the duct. For a longer-lasting
seal, secure the tape with staples (into wood) or
mastic (on metal).
• Acrylic duct mastic (a thin putty available from
heating and cooling equipment suppliers and mailorder suppliers of weatherization materials)—the
best duct-sealing material. It can be installed with
a brush, spatula, or your fingers if you wear rubber
gloves. For larger openings or gaps, use fiberglass
mesh tape to reinforce the duct mastic (special
tape designed for mastic is available or you can
use standard gypsum wall board tape). The finished coat of mastic should be about 1/8" inch
thick and you should not be able to see the seam
through the mastic coat.
Bottom board
Main duct
Patch sealed
with mastic
Duct access hatch sealed with mastic
In some situations, the
seams may be accessible from
inside the home without removing
the furnace. Some furnaces have a
bottom cooling coil compartment
with a removable panel; if the furnace has such a compartment, but
doesn't have a cooling coil, it provides a way to access the main
duct beneath the furnace. Also, the
heating coils in an electric furnace
can be taken out to provide access
to the duct—though this is a difficult and potentially hazardous job
that should only be attempted by a
skilled technician. Similarly, the
entire furnace itself can be temporarily removed to seal leaks, but
this too is a job best left to professionals.
ZCracks in areas with the highest air pressure (closest to the
furnace fan) will leak the most
air—sealing them will have the
biggest impact on energy savings.
! Air needs a path to get back
to the furnace. Never block the
louvers or grilles in doors or walls
enclosing the furnace.
Thoroughly clean the duct first with a solvent or steel
wool before patching.
Lighting is responsible for about 12% of energy used in a typical American home.
Nearly every home can benefit from improved lighting efficiency. No
matter the type of lighting in your home—ceiling fixtures, table
lamps, track lighting, etc.—there are opportunities to lower your
monthly energy costs by reducing your electricity use for lighting. And
the quality of light can often be improved at the same time.
The average home has nine lights left on for more than three hours every day. Any light
bulb burning more than two hours per day on average is a good candidate to be
replaced with a compact fluorescent lamp (see below).
These simple techniques to lower lighting costs and improve lighting quality can be
done with little or no skill and low cost:
Replace incandescent light bulbs with compact fluorescents
($, low skill)
Compact fluorescent lamps (CFLs) use one-third to one-quarter the energy of incandescent bulbs, and last up to ten times longer. They screw into
standard light bulb sockets, and are available in many sizes and shapes
to fit almost any fixture. They're more expensive to buy than incandescent bulbs, but save several times their purExample of savings from a compact fluorescent bulb
chase cost because of reduced electric use and
longer life (less frequent replacement).
If you replace one 75-watt incandescent bulb (that
costs 75¢ and is on for four hours per day) with a 20watt compact fluorescent lamp (that costs $5 and is
also on for four hours per day), you'll save about $3
by the end of the first year, and more than $50 over
the expected seven-year life of the CFL.
The packaging for a compact fluorescent lamp
usually indicates the equivalent wattage of the incandescent
bulb it replaces. For example, a 20-watt CFL gives off about the
same amount of light as a 75-watt incandescent bulb. Note
that CFLs take up to a minute to reach full brightness.
Install energy-saving controls on exterior lights
($, medium skill)
Outdoor lighting should be off when it's not needed: during the day, and sometimes at
night when there's nobody around. Photocell switches can automate lights by shutting
them off when the sun comes up; timers can automatically turn off outdoor lights in the
evening—such as patio lights that are no longer needed when you go indoors; and
motion sensors (which sometimes have built-in photocell switches) can turn on the
lights only when they detect movement. These devices are available at hardware stores
and home centers for as little as $15. Hard-wired fixtures may require an electrician.
ZThe lamp that uses the least
energy is the one that’s switched
off. Turn off the lights when you
don’t need them.
Clean fixtures
(FREE, low skill)
Lamps, lampshades and light bulbs should be kept clean to maximize light output. You
may even find that once a fixture is clean it gives off the same amount of light with a
lower-wattage bulb.
Use low-wattage light bulbs
($, low skill)
In some fixtures it's possible to use lower-wattage light bulbs without any reduction in
functional light quality.
Refrigerators account for about one-sixth of the typical electric bill for
an American home and 9% of the total energy (electricity, gas, and oil)
used in manufactured homes. Old, inefficient models may be candidates for replacement.
Today's refrigerators use 40% less electricity than 20-year-old models.
An old, inefficient refrigerator can cost up to $280 a year to run; a new,
efficient refrigerator—while expensive—can save more than $150 each
year over a 20-year-old model. While the savings will be less if replacing a younger refrigerator, it still will save between $35 and $70 per
year. That's $525 to $1,050 during the 15-year typical lifespan of a
You should consider replacing your refrigerator if:
The one you have now is more than 15 years old.
Your refrigerator is not keeping food cold or is especially noisy.
Replacing the refrigerator can generate the greatest savings, but other techniques can
also improve the performance of your existing unit.
Properly operate your existing refrigerator
(FREE, low skill)
If you decide not to replace your refrigerator, these tips can help save money with your
existing one:
If the refrigerator is in direct sunlight, or near an oven, dishwasher, or other heat
source, it has to work harder to stay cool. Relocate it if
possible, or shield it from excess heat.
If the door seals aren't airtight (they won't hold a dollar bill snugly when closed), replace them.
Dispose of old refrigerators
Old refrigerators are energy hogs that may cost as
much as $280 a year to run. Keeping one around as a
second fridge is an expensive proposition. Check with
your local energy utility to see if they offer refrigerator
recycling incentives and disposal programs.
Alternately, contact your local municipal solid waste
agency to make arrangements for disposal.
The proper temperature for refrigerators is between
37° and 40° Fahrenheit; freezers should be between
0° to 5°. A refrigerator that's 10° cooler than it needs
to be can use 25% more energy.
Manual-defrost models should be defrosted regularly—less energy is needed when there's no frost buildup.
Make sure that air can circulate freely behind the refrigerator, or wherever the
coils are located. Air flow is required to carry heat away.
Periodically vacuum off the coils to improve the operating efficiency.
Buy a new refrigerator
($$-$$$, low skill)
Refrigerators have an EnergyGuide label (often a tag hanging inside
the unit) that tells you how much electricity they use based on standard test conditions. Pick one with low annual energy cost—the
smaller the number of kilowatt hours (kWh), the less it will cost to
operate. The triangular-shaped arrow should be to the left-of-center
on the energy-use line in the middle of the EnergyGuide.
Look for ENERGY STAR qualified models, which are among the
most energy-efficient models sold. These will be indicated by a
blue label such as the one at right.
Check with your local utility to see if they offer rebates on new
energy-efficient models, or recycling incentives for older models.
Other buying tips
Refrigerator-freezers that have the freezer compartment on the top or the bottom are generally more energy efficient than side-by-side models of a similar
A refrigerator that's bigger than you need can waste energy and space. One
that's smaller than you need can mean extra driving for groceries. Carefully consider what size is best for you.
Most manufactured homes have conventional storage-tank water heaters located in closets. Older manufactured homes sometimes have smaller water
heaters in kitchen cabinets instead. Electric and gas-fired water heaters are the
most common.
Water heating accounts for about 15% of energy costs in a typical manufactured home. Improving the energy efficiency of the water heater can save a significant amount of money over the water heater's lifetime.
Electric water heater
Nearly every home can benefit from water heater maintenance and efficiency
improvements. The more hot water your family uses, the greater the opportunities for
There are a number of simple actions you can take to reduce your water heating
Insulate the tank
($, medium skill)
Water heater with
insulation jacket
! Before attempting any work
on your electric water heater,
make sure the power to it is shut
off at the circuit breaker.
! Important safety precautions must be taken when insulating a water heater.
Insulating an electric water heater is one of the most effective and
least expensive energy-saving steps you can take, saving more than
enough money in one year to pay for the cost of doing it. After that,
the savings go in your pocket. Insulation jackets for water heaters usually cost $20 or less at home centers. Follow
the installation instructions that come with
Fix Those Leaks!
the jacket. Alternatively, standard fiberglass
batt insulation can be used. Seal the seams
Leaky faucets and showwith vinyl tape, and wrap the entire heater
erheads can waste huge
amounts of water—and
loosely with wire ties to hold the insulation in
energy if it's the hot water
place. No matter how you choose to insulate
that's leaking. A leak that
the water heater, pay close attention to these
produces one drop per
safety instructions:
Cover the sides and top of the heater, but cut flaps for
the electric element access panels and the thermostat.
Do not cover warning labels on the tank.
Do not insulate gas or oil fired water heater tanks. Over
time, the insulation may sag, blocking air intakes and
creating a safety hazard.
second will waste over
190 gallons per month, or
2,300 gallons per year. A
leak that fills an 8-ounce
cup in a minute will waste 2,700 gallons per month
and 33,000 gallons per year—enough to fill a swimming pool! If this is hot water, that's a lot of water
heating dollars down the drain!
Insulate water pipes leading from the tank
($, low skill)
Insulating the water pipes slows heat loss; it also raises the temperature of hot water at
the tap by 2° to 4°, which lets you lower the temperature
setting on the water heater. Pipe insulation is usually a
foam sleeve, slit lengthwise, that costs less than 50¢ per
foot at home centers. Insulate all of the hot water piping
that is accessible. It is especially important to insulate the
first six feet of pipe coming out of the water heater. Fasten
the insulation sleeve with tape, wire or cable ties at least
Pipe insulation
once per foot. For a snug fit, get pipe insulation that has an
inside diameter that's the same as the outside diameter of the pipe. Miter-cut corners
and tape them closed. Insulating cold water pipes is also beneficial, especially in humid
climates. It will reduce sweating in summer—a problem than can cause moisture damage.
Lower the water heater thermostat
(FREE, low skill)
If the water heater temperature isn't high enough, there are
some circumstances in which
Legionella bacteria can grow—the
cause of Legionnaires' disease.
120° is usually considered hot
enough to prevent this, but
homeowners at high risk of susceptibility (such as transplant
patients and smokers with chronic lung conditions) may be
advised to keep their water
heater settings higher (140°).
Check with a physician if uncertain.
Z If you'll be away for an
extended period, turn the thermostat to the lowest possible
setting—or turn the water heater
off completely (make sure you
know how to relight the pilot
light if your gas heater has one).
! Make sure the power is off
to electric heaters before draining the tank. Exposing the electric elements to the air with the
power on may cause them to
burn out.
Older tanks that have never
been cleaned will often require
additional procedures. Check
with a service technician.
For every 10° you turn down the water heater, you'll save about 3% to 5% on water heating costs. A setting of 120° (usually halfway between "low" and "medium") is usually hot
enough. If you have a dishwasher without booster heat, set the thermostat at 140° (typically "medium"). Some electric water heaters have two thermostats—one for each element. Adjust both to the same setting. A side benefit of lower thermostat setting is that
lower water temperature reduces the risk of children scalding themselves. You can check
the temperature of your water at the taps by continually running hot water in cup with a
thermometer placed in it.
Clean the tank
(FREE, medium skill)
Once a year, drain a gallon of water through the spigot at the bottom of the water heater
to remove sediment, which decreases its energy efficiency—and can, in some situations,
provide a more protected environment where Legionella bacteria can grow.
Install low-flow showerheads and faucet aerators
($, low skill)
If you have an older showerhead, it may use as much as 5 or
7 gallons per minute, wasting a tremendous amount of hot
water. Replacing it with a high-quality new one that uses no
more than 2.5 gallons per minute will probably pay for itself
in a matter of months—and you'll be far less likely to run out
of hot water. In many homes, the existing showerhead can be
unscrewed and a new one installed; you'll need a pipe
wrench and Teflon® tape.
Faucets should also be retrofit. Low-flow aerators screw into
standard faucets to reduce the flow and aerate the water, so
that it still feels like a full flow. These cost just a dollar or two,
and can pay back the expense in just a few months.
Low-flow showerhead
Replace your water heater
($$, PRO)
If warranted, replace the water heater with a new, more efficient unit. If a water
heater was manufactured before 1980, it may be cost-effective to replace it
with a more efficient model. Always check the EnergyGuide label to determine
the unit's energy efficiency.
EnergyGuide labels
help you identify energy-efficient water
Sunlight coming in through the windows is a major contributor to cooling costs in hot
and sunny climates such as Arizona and Florida. Trees and other foliage can be very
effective in shading a home, but there are other relatively simple options available to
reduce solar gain while maintaining views. Additional benefits of blocking sunlight from
entering windows include less fading of furniture and carpets; more comfortable temperatures in rooms with large windows; and less glare.
Following these tips will reduce the cost of cooling your home and make it more comfortable during the hottest parts of the day.
If you answer YES to any of these questions, you should consider ways to reduce your
home's solar gain:
Are you in a hot climate?
Do you find it difficult to keep your home cool in summer, especially during midday and early afternoon, despite having a properly maintained cooling system?
Do you have large windows facing west or east that receive direct sunlight in
There are some simple actions you can take to reduce the impact the sun has on your
cooling costs.
Install sun screens
($$, high skill)
Sun screens are often the least expensive window-shading option that retains a full view
through the window. Most can be removed in winter so as not to restrict solar heating.
Typical sun screens absorb more than a third of the sunlight's heat. Like regular window
screens, sunscreens have aluminum frames and are installed on the exterior side of the
windows. They're available in several colors and are often used to shade porches. Do-ityourself fabrication is difficult; sun screen kits are available, which are simpler. Having a
professional build and install custom sun screens should cost about $2 to $4 per square
Install exterior awnings
($$-$$$, medium skill)
Awnings are expensive but popular in hot, sunny climates; they intercept solar heat
before it gets to the window, which reduces the energy needed for cooling. When selecting awnings, consider:
How much shade do you want? This is
affected by how low the bottom of the
awing extends (called the drop) and how
far it sticks out (called the projection).
How important is it to maintain a view
out the window?
How much will an awning cost? Do-ityourself kits and store-bought (manufactured) awnings are less expensive than
custom-made ones.
Metal awning
Fabric awning with sides
On the south side of the house, the drop should be 45% to 60% of the window height.
Awnings on the east and west sides need to extend lower to block the morning or afternoon sun, which is low in the sky; these should have a drop of 60% to 75%. Awnings
without sides will work better if they're wider than the windows.
Apply reflective window film
($$, high skill)
Metalized plastic window films can block half to three-quarters of the sunlight's heat
and glare and eliminate almost all of the ultraviolet rays from the light coming through
the window. The reflective film is installed on the inside of the window and makes the
window more reflective when viewed from outside. Note that these reflective window
films block daylight in addition to solar heat—though newer "low-e" films let through
more visible light while still stopping most of the heat. Reflective window films are difficult to work with, making for a potentially frustrating do-it-yourself project. Professional
installation will cost about $3 per square foot. Low-quality reflective films can become
cloudy or start to deteriorate after just a few years; high-quality ones last longer and
have scratch-resistant coatings.
Don't confuse reflective window films with tinted films that color the glass. Those films
absorb, rather than reflect, heat—so they're not as effective in preventing solar heat
from entering the home, and they can actually heat the glass to high enough temperatures to cause damage.
Use interior shades to block sunlight from entering the home
($$, medium skill)
Also consider plantings for
Planting trees or shrubs can
provide very effective shade.
Taller trees without low branches on the south side will block
the higher summer sun while
not blocking views through
windows significantly. Smaller
trees or shrubs on the east and
west will block the lower summer sun, but they also impact
views. If permanent plantings
aren't permitted or are impractical, vines on a temporary trellis and tall annuals can provide
excellent shading; consider
clematis, morning glory, and
Window shades and blinds with metalized or bright white reflective surfaces can effectively block solar heat. The following table describes some options available at many
window treatment retailers:
Solar heat
View and light
Opaque roller shades with
white surfaces facing the
Reduces solar gain by about 80%
No view or light when the shades
are drawn.
Roller shades with metalized
plastic window film
Reduces solar gain by about
Preserves the view and lets in
some light
White Venetian blinds
Reduces solar gain by about
Blocks most of the view and light
Install a reflective roof coating
($$$, PRO)
A great deal of unwanted heat gain enters a home through the roof—the less insulation,
the more summertime heat gain. Reflective elastomeric roof coatings are available for
metal, asphalt shingle and other types of roofs that will reflect more than 75% of the
sunlight striking the roof. Most of these coatings are acrylic and relatively easy to apply,
although they do require working on top of the roof. They have the added benefit of fixing small leaks in the roof and extending its life. Light-colored roofs should be cleaned
each year to keep them reflective.
Storm windows can be installed over existing windows to improve their insulation value and dramatically reduce air leakage and drafts. Separate, removable
storm windows can be installed in seasons when heating or cooling is typically
necessary (and the windows don't need to be opened), and removed during
more temperate seasons or if windows need to be operable for ventilation.
Storm windows are most needed in cold climates, and less important in
warmer regions. Triple-track storm windows, mounted outside the primary windows, offer the advantages of easily opening and closing as well as providing
screens, but they are quite expensive and generally must be installed by professionals. Interior storm windows have been found to work best for manufactured homes, and only these will be addressed here.
One of the things that distinguish manufactured homes from other types of
homes are the way windows are installed. For that reason not all storm windows
will work on manufactured homes. Be sure you select windows suitable for your
Interior storm window
with flexible plastic
Following these tips will reduce the cost of heating your home and make it more comfortable during the coldest times of the year.
If you answer YES to any of these questions, you should consider adding
storm windows:
Are you in a colder climate?
Was your home built prior to 1976, and does it have the original
windows? (After 1976, manufacturers were required to provide
homes with either double-pane windows or storm windows in
many parts of the country.)
Was your home built after 1976, but the original storm windows
are lost or broken (and your primary windows are single-pane)?
Do you have jalousie windows?
Do the windows feel uncomfortably cold in winter, and you notice
drafts coming through them?
Jalousie windows with
louvered pieces of glass,
are notoriously leaky and
should be replaced.
Do your heating bills seem excessive?
There are a number of options for adding storm windows to manufactured homes.
Install interior storm windows
($$-$$$, medium to high skill)
A number of different types of interior storm windows are available for different budgets
and primary window types. Storm windows are available from home centers as kits or
already assembled. The kits are designed to be installed by homeowners with a minimum of experience and tools; the preassembled storm windows usually require more
skill and equipment.
Interior storm windows can be either fixed or sliding. Fixed storm windows are removed
seasonally—either the entire panel is removed, or the sash is removed and a frame
remains behind. The bottom of a fixed storm window should be supported by a sill, clip,
! Old jalousie and awning
windows require special storm
window frames with holes to
accommodate the protruding
cranks, or the cranks can be
removed when the storms are
! Don't install a fixed storm
window over a fire escape
(egress) window without making
sure that everyone living in the
home can quickly and easily
remove it.
or on a wood or aluminum strip to support the window's weight. Because they are
removed seasonally, they can be lost or damaged. For the handy do-it-yourselfer, fixed
storm windows can be made from wood frames and plastic sheeting.
Sliding storm windows are more expensive than fixed ones. They usually have aluminum
or vinyl frames and a spring loaded latch. Their primary advantage is that they can be
left on all year long and opened for ventilation. They're compatible with vertical or horizontal sliding primary windows.
Often a combination of fixed and sliding storm windows is the best solution, with the
sliding windows being used for ventilation and emergency egress requirements.
When considering window material, the choice is either glass or plastic. Plastic glazing
costs less than glass. It's also lighter, which is a big benefit for removable storm windows. Both rigid plastics (acrylic and polycarbonate) and flexible plastics (vinyl, polyester, and polyethylene) are available. Each material has advantages and disadvantages. For example, acrylic is prone to scratching; polycarbonate may yellow over time;
and thinner, flexible plastics may tear.
Whatever type of storm window you choose, the frame should seal tightly and continuously against the interior wall or window trim using foam, foam tape, magnetic seal, or
other method.
Install plastic disposable window insulating kits
($, low skill)
These plastic kits, available at home centers and other retail outlets, are designed to be
applied over the primary windows for seasonal use. They install with double-sided tape
and shrink to fit with heat from a hair dryer. Effective at reducing air leakage through
cracks around windows and patio doors, these kits are a low-cost alternative to storm
Air leaking through the walls, floors, and ceilings of your home can have a significant
impact on your heating and cooling bills, as well as your comfort. It can also contribute
to moisture-related problems. While windows and doors are common sources of air
leaks, more important leakage sites are often in less visible places. (Leaks in the ducts
are also very important to seal—see page 10.)
Following these tips will reduce the unwanted exchange of warm and cold air through
your home's walls, floor, and ceiling, which will in turn result in lower heating and cooling costs. It will also make your home a lot more comfortable by reducing drafts.
Almost all homes can benefit from air sealing. If you answer YES to any of these questions, your home may be especially in need of sealing:
Is your home more than 10 years old?
Do you frequently feel drafts on windy days?
In winter, is the air near the floor more than about 5° cooler than the air near
the ceiling?
Is it difficult to heat or cool your home—even after having performed heating
system (page 5) and air conditioning system (page 7) maintenance?
In general, large openings should be tackled first, then smaller ones, and
finally the little holes and cracks. Most of these techniques do not require
skill or expensive materials, but they will require time and care.
Descriptions of common leakage sites—listed in order of importance—follow below, along with repair suggestions.
Patch/replace torn or missing bottom board
($, medium skill)
The bottom board (also called the belly or underbelly) is the protective covering on the bottom of the home. If torn, it can be a major source of air
leakage, driving up energy costs—and a potential source of moisture problems. Patching the bottom board with durable materials designed for that
purpose is the best way to reduce this type of energy loss.
Bottom boards consist of either a flexible (paper or fabric) or rigid
material. If you have a flexible bottom board, use similar material for
a patch, or purchase special patching
material from a manufactured home supply retailer. A combination of adhesives,
foam and fasteners works best for producing a long-lasting, airtight seal. When
possible, fasten patches to the floor
joists with staples, nails, or screws. If no
backing is available, you can use construction adhesive to glue the patch to
the bottom board.
Using foam sealant on the
bottom board
Using mastic to seal a bottom
board patch
Bottom board penetrations sealed with
patch and foam
A variety of materials are used for rigid bottom boards,
including plywood, paneling, and rigid insulation. To patch a
rigid bottom board, cut a rectangle around the damaged part
Backer board
Fiberboard bottom board
Patching a rigid bottom board
and remove it. Then insert one or more pieces of wood
or plywood (backer board), large enough to overlap the
empty rectangular hole. Drive screws up through the
bottom board and into this backer board to hold it
tightly in place. This provides something rigid to secure
the patch to. Cut a patch slightly smaller than the opening, and fasten it to the backer board with screws. Then
caulk the joint around the patch, providing a good seal
to the original bottom board.
Seal gaps and cracks in the walls, floor and ceiling
($, medium skill)
To seal large openings use a piece of material that is the same as or similar to the surface being patched. To cover a hole in a concealed area, such
as behind a washing machine, cut a patch that overlaps the
Avoiding moisture problems
opening by a few inches on all sides. Apply adhesive around
the opening, and press the patch into place. Use screws or
As you reduce air leakage through your home's walls,
nails if necessary. Then use caulk or expanding foam to seal
floor and ceiling, taking steps to avoid moisture problems can become more important. This is especially
remaining air leaks such as around a pipe, flue, or wiring that
true in hot, humid climates for homes that are air
passes through the patch.
conditioned. The following tips are useful for all
• Ensure that kitchen and bathroom exhaust fans
are operable and used regularly (bath fans should
be wired to the light switch and operate when the
light is on).
• Make sure that clothes dryer vents are unobstructed and exhaust directly to the outside; they should
not be vented to the crawlspace under the home.
• Install and periodically clean rain gutters; use a
downspout and extension to direct water away
from the home.
• Maintain or install a 6-mil plastic vapor barrier on
the entire ground surface under the home.
Caulk works well for small cracks. Openings more than about a
quarter-inch wide should be stuffed with foam rubber backer
rod or some other compressible material, and then caulked or
sealed with expanding foam.
For most indoor applications, a good quality latex caulk is satisfactory. It's inexpensive, easy to apply, paintable, and cleans
up with water. For exterior applications, more expensive silicone or polyurethane caulk will perform better. Areas that are
exposed to heated surfaces such as around flues should be
sealed with a caulk specially formulated for high temperatures.
Urethane foam sealant, available in a can, is excellent for sealing small to medium sized openings in a wide variety of locations, including the bottom board.
Some common leakage sites include:
! The most important surface
to seal in manufactured homes is
the interior wall surface. The
exterior wall surface is designed
as a weather barrier to prevent
rain from leaking in—but often is
designed to be vented, so that if
water gets into the wall it can dry
to the exterior. Don't seal the
walls from the exterior except to
stop water from leaking in.
Openings between the furnace closet and the attic and/or floor cavity.
Plumbing penetrations where pipes enter exterior walls, or between exterior
(unheated) water heater closets and adjoining rooms. Look under sinks, behind
and under bathtubs, in back of washing
machines, and around hose bibs and outdoor
Penetrations for electrical outlets, service panels and light fixtures.
Flue and vent pipes.
Exhaust fans.
Openings from closets and cabinets into walls,
floors or attic.
Hole in floor at plumbing penetration
behind tub
Cover window air conditioners
($, low skill)
If left in place during the winter months, window air conditioners can result in very significant air leakage through the unit. Interior and exterior covers, available at home centers, can reduce this leakage. Alternately, the units can be removed and the windows
closed and weatherized. During the entire year, gaps around window air conditioners
should be sealed.
Seal leaky windows—particularly if they do not close properly
($, low skill)
Weatherstripping or caulk can be used to seal cracks and gaps around window frames.
Alternatively, do-it-yourself plastic window insulating kits, available at hardware stores,
can reduce winter drafts coming from leaky windows. A more expensive option that also
improves window insulation is to install storm windows (see page 21).
Windows should be repaired if they no longer operate properly or if glass is broken. A
contractor can help with this task. Replacing entire windows with better-performing units
is generally not cost effective from an energy standpoint unless the windows need to be
replaced anyway.
! Special attention should be
paid to sealing jalousie and older
crank-out awning windows, as
these are often especially leaky.
Fix poorly fitting exterior doors
($, medium skill)
If the door itself is in good shape but air leaks in around the edges, weatherstripping
may be the answer. The first thing to check before starting is the kind of door your home
has: does it open out, or open in?
Doors that swing out usually have weatherstripping attached in a track on the door
frame, but sometimes on the door itself. The weatherstripping on these doors is typically
a vinyl flap. The vinyl flap can be replaced, or you can add silicone tube weatherstripping
to it.
Doors that open in are weatherstripped the same way as doors on site-built homes. Just
follow the instructions on the packaging for the weatherstripping product you select.
When shopping for weatherstripping look for flexibility and longevity. Silicone rubber,
neoprene rubber, and plastic-jacketed foam rubber are recommended. Vinyl tubing, felt
and foam tapes generally will not perform as well or last as long.
Insulation in walls, floors, and ceilings acts like a blanket,
keeping the heat inside your home in winter—and keeping
the heat out of your air-conditioned home in summer. Like a
blanket, the thicker the insulation, the better it works. The
performance level of insulation is called its R-value, which
indicates its resistance to heat flow. (As R-value goes up,
energy use goes down).
Insulation in manufactured home walls and floors is usually
fiberglass batts; ceiling insulation is usually loose-fill fiberglass or cellulose. Prior to the first energy crisis in 1973,
most homes built in the U.S.—including manufactured
homes—contained little insulation. The level of insulation
used in homes has been increasing ever since. The recommended amount of insulation for a given house depends on
its climate; colder climates generally demand more insulation.
Fiberglass batt insulation
Loose fill insulation
Determine if your home is a candidate for adding insulation. Decide what part of your
home, if any, should be insulated: floor, ceiling and/or walls.
Many manufactured homes can benefit from additional insulation. If you answer YES to
any of these questions, your home may be a candidate:
Z Prevent rising damp by laying plastic sheeting on the bottom of the crawl space—this can
prevent condensation from making the insulation wet (which
reduces its performance), and
helps prevent moisture problems.
Was your home built before 1994? (That year, stricter insulation standards went
into effect.) If your home was built before 1976 and has never been upgraded,
then it can almost certainly benefit from more insulation.
Is it difficult to heat or cool your home—even after having performed heating
system (page 5) and air conditioning system (page 7) maintenance, and sealing
air leaks in the ducts (page 10), walls, floor and ceiling (page 23)?
In colder climates, are the walls cool to the touch in winter?
During the winter, is the air near the floor of your home at least 5° cooler than
the air near the ceiling, and is the house drafty?
Using the techniques described in the box Measure your existing insulation
level on page 28, is your home significantly underinsulated—and is there room
for more insulation to be added to your floor, ceiling and/or walls?
Adding insulation to a manufactured home is almost always a job best done by professionals. Specialized equipment is usually required, and the sort of caution learned by
experience must be taken to prevent structural damage to the home or moisture problems. In general, adding insulation to the floor is the most cost-effective approach with
manufactured homes, followed by adding insulation to the ceiling. The amount of insulation that can be cost-effectively added to wall, floor, or ceiling cavities depends on the
amount of insulation already there, how much empty space remains, and your local climate and fuel costs. The following descriptions of these options will give you an idea of
what a professional contractor will do when these upgrades are performed.
! The insulation contractor
should be careful not to damage
ducts in the floor with their blowing equipment.
Add insulation to the floor
($$$, PRO)
Floors in older manufactured homes can lose a lot of heat in
cool climates due to relatively low levels of insulation.
Floors can also be a big source of air leakage—wasting energy and potentially causing moisture problems in most climates. Floor insulation is commonly added to manufactured
homes by blowing loose fiberglass wool through a hose into
holes cut in the bottom board. The holes should be sealed
with a durable patch (see page 23) after the insulation is
added. Alternatively, insulation may be added through a filltube inserted into holes cut in the home's rim joists—however, care must be taken not to damage the joists' structural
integrity. These holes should also be patched.
Blowing insulation into the floor cavity
Add insulation to the roof
($$$, PRO)
Adding insulation to roof cavities is cost-effective in most
climates for manufactured homes that don't have adequate
ceiling insulation. The primary benefit is reduced winter
heating loads, but it also reduces summer cooling costs.
Typically, roof cavity (ceiling) insulation is blown in through
holes in the ceiling, holes in the roof, or holes through the
raised edge of a home's metal roof. If insulation is added
through the ceiling, holes will need to be drilled between
each roof truss, and in each half of double-section homes.
The holes should be patched afterward with unobtrusive
gypsum board, plastic plugs or trim board. If blown through
the roof, the roof must be repaired afterward to prevent
water leakage. Insulation can also be blown in from the end Blowing insulation into the roof
of the home with a long pipe. Before adding insulation to
the roof cavity, the ceiling should be sealed against air leakage to prevent insulation
dust and fibers from blowing into the living area.
Another method of adding roof insulation to manufactured homes with unvented metal
roofs is to install rigid insulation boards right on top of the existing roof, then installing
new waterproof roofing on top
of the insulation. This is a more
expensive option and it should
be done in conjunction with
blowing insulation into the roof
cavity to maximize effectiveness. Before selecting this
option, make sure the attic cavity is tightly sealed against air
infiltration. A leaky attic will
negate much of the benefit of
added roof insulation.
Blowing insulation through
Plugging the ceiling hole
! When adding roof-cavity
insulation, the contractor must
take care to maintain clearances
between the insulation and
recessed ceiling light fixtures and
flues to avoid overheating; make
sure the ceiling is strong enough
to support the weight of the additional insulation; and not block
ventilation in vented attics.
the ceiling
Add insulation to sidewalls
($$$, PRO)
Z Since the space under the
home must be vented, insulated
skirting generally is not an effective strategy to save energy.
The walls of older manufactured homes may have significant voids where insulation is missing. Adding wall insulation is difficult and expensive, but it can be cost-effective in colder climates that have high fuel costs. There are at least four different ways to add insulation to
walls: blowing insulation through holes
drilled in the exterior siding; blowing
insulation through holes drilled in the
interior wall; installing fiberglass batts
after removing the exterior siding; and
stuffing fiberglass batts into walls from
below. All of these techniques are difficult and expensive. On some homes, several different methods might be combined because of variations in the walls’
Stuffing fiberglass batts
Blowing wall insulation
into a sidewall
Measure your existing insulation level
Homes in colder climates should have a minimum of
about R-11 in the walls and R-21 in the floor and ceiling. Each inch of fiberglass-batt insulation provides
an insulating value of about R-3.2, and every inch of
loose-fill fiberglass provides about R-2.5. For example, a wall with 3-1/2" fiberglass-batt insulation
achieves about R-11.
Figuring out how much insulation there is in your
home can be tricky. For walls, you can sometimes
remove the cover plate from an electrical outlet (turning off power at your circuit breaker first) and look
into the gap next to the outlet box. For floors, you
may be able to remove a floor-mounted heating register. For your ceiling, removing a recessed light fixture,
electrical cover plate from a ceiling-hung light fixture,
or bathroom fan cover plate may reveal the insulation. Alternately, in a hidden location such as in a
closet or cabinet, you can cut a hole into the wall,
floor, or ceiling cavity—a hole that can be repaired
One important limiting factor in being able to add
insulation to your home may be the thickness of the
wall, floor, or roof cavity. If your floor cavity is only 6"
deep, you'll only be able to achieve about R-15 with
loose-fill insulation.
Common-sense, low-cost or no-cost strategies that you can implement today to lower
your energy bills are described below.
During the cooling season:
Close drapes or shades on the sunny side of the house to reduce solar heat
gain through the windows.
2. Set the thermostat to 78°F or higher. When the house is empty, set it to 82°F or
3. Turn off the air conditioner when nobody's home, or when cooling isn't needed.
If conditions permit, open windows for ventilation instead of using the air conditioner. Be aware that in very humid conditions, opening windows will introduce
moisture which may force the air conditioner to work harder to remove.
4. If you use an air conditioner, leave storm windows and storm doors in place—
they keep cool air inside when it's hot out, just as they keep warm air inside
during winter. However, you may want to remove some of the storm windows so
you can open the windows for ventilation on days when air conditioning isn't
needed—even if you're primarily relying on air conditioning.
During the heating season:
Open the drapes or shades on the sunny side of the house during the daytime
to gather as much solar heat as possible—then close those drapes or shades at
night to reduce heat loss.
2. Set back the thermostat at night and when the home is unoccupied.
Every degree the heat is lowered saves you up to 5% on heating costs.
(Heat pumps should only be set back 5° to prevent excessive use of
the built-in backup electric heating.) A programmable thermostat can
automate this process and offers options for multiple settings to fit
your family's lifestyle.
Programmable thermostat
3. To prevent heated air from going up the chimney, keep the fireplace damper
closed except when you're using the fireplace. If the fireplace doesn't have a
damper, the fireplace opening can be sealed with a snug-fitting cover.
All year long:
When the air conditioning or heat is on, keep windows and doors closed.
2. Wash only full loads of laundry in the coolest water practical, and rinse in cold
3. Clean the clothes dryer lint filter after every load to maximize drying efficiency,
and dry only full loads of clothes—but don't overload.
4. Run the dishwasher only with full loads, and select an air-dry dishwasher cycle
so that electric heating elements aren't used for drying.
5. Reduce hot water waste. Don't leave the water running while brushing your
teeth or shaving.
6. Turn the water heater off when everyone will be gone longer than a week.
Turn off lights, televisions, and stereos when you leave the room. Plug televisions and stereos into a power strip that can be switched off to eliminate standby power consumption—called phantom loads. It will take equipment slightly
longer to turn on, but will save the energy they use even when they're turned
8. Turn off outdoor lighting during the day (see page 14 for more on photo-sensor
9. Use natural daylight indoors during the daytime by opening the drapes or
10. Maintain your refrigerator at an optimal temperature setting: 37° to 40° for the
refrigerator compartment and 0° to 5° for the freezer.
11. Let hot foods cool off before you put them in the refrigerator or freezer.
12. Cover liquids and wrap foods stored in the refrigerator. Uncovered foods release
moisture and make the refrigerator work harder.
13. Reduce or eliminate the use of high-energy-use appliances, such as a second
Your Mobile Home: Energy and Repair Guide for Manufactured Housing, by John
Krigger, Saturn Resource Management, Helena, MT ( This comprehensive and detailed guidebook contains many photographs and diagrams to explain repair and upgrade procedures. It is geared
towards the handy do-it-yourselfer, but is very useful for any manufactured
home owner. Specific items of interest include cleaning a water heater tank,
making wood-framed storm windows, repairing primary windows, and insulating
manufactured homes.
2. Consumer Guide to Home Energy Savings, 8th Edition, by Alex Wilson, Jennifer
Thorne, and John Morrill, American Council for an Energy Efficient Economy,
2003 ( This 247-page comprehensive reference guide is
written in plain English and is full of tips, charts, diagrams and explanations of
a myriad of energy savings strategies. Of particular interest is the detailed information on when and how to select a new furnace, air conditioner and water
3. DOE Energy Savers Booklets ( This
free booklet is also available in Spanish. It is a guide to easy, practical solutions
for saving energy throughout the home—from insulation to appliances and lighting. It can be downloaded from the Web site above or ordered by calling 1-877EERE-INF (1-877-337-3463).
4. Weatherization Field Guide for Pennsylvania, Pennsylvania Weatherization
Assistance Center, 2004 ( This is the handbook used
to train weatherization contractors working in Pennsylvania. It contains a special
chapter on manufactured homes and in particular contains a great deal of detail
on insulating manufactured homes. Free from the Web site.
Web sites
Weatherization Assistance Program ( Information about the Weatherization Assistance Program.
Weatherization Assistance Program Technical Assistance Center
( Links to the manufactured home energy audit tool
(WX Assistant) which provides savings to investment ratios for many energy efficiency upgrades customized for your home (but is fairly complex to use), and a
refrigerator replacement analysis tool.
HUD Energy Efficient Rehab Advisor
( This Web site recommends energy
efficiency measures for many types of rehab projects. It estimates costs, energy
savings and additional benefits. Users should keep in mind that it is based on
site built construction, not manufactured homes.
EERE Energy Savers ( This U.S.
Department of Energy Web site is a gateway to consumer information on energy
efficiency and renewable energy.
Home Energy Saver ( A do-it-yourself web-based home energy auditing tool.
ENERGY STAR ( Research ENERGY STAR products and
find remodeling contractors affiliated with the Home Performance with ENERGY
STAR program.
California Consumer Energy Center Consumer Energy Tips ( Contains numerous energy-savings tips and recommendations.
Home Energy Magazine, Berkeley, CA ( The Web
site for this magazine contains many back issues in a searchable database.
These articles are helpful for more in depth research and practical advice on
specific topics.
Nordyne ( Contact for copies of operating and service
manuals for Intertherm and Miller heating and cooling equipment. The Web site
also contains tips for selecting a heating and air conditioning contractor and
recommendations for what should be included in an annual maintenance agreement.
York International ( Contact for copies of operating and
service manuals for York heating and cooling equipment.
Coleman ( Contact for copies of operating and
service manuals for Coleman heating and cooling equipment.
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