Sealing the Existing Home
Technology Snapshot & Benefits:
Most people aren't aware that air leakage amounts to 30-40% of a home's
heating and cooling bills. Stopping air leakage is important not only for energy
savings, but also for protecting your home from the damaging effects of moisture.
Air, leaking into walls from the interior of the home, carries humidity with it. This moisture hits a cold surface and condenses, causing the insulation and
surrounding wood to get wet. Eventually, the air leakage can lead to mold growth and wood rot.
It is a common misconception that
the majority of a home's air leakage comes through windows and doors, but in
actuality, only 10-15% of air leakage is through
windows and doors. That is why window replacement is seldom a
cost-effective means to save energy. There are lots of ways to greatly
improve the efficiency of windows without replacing them.
The use of a blower door can make locating and sealing air leaks much easier.
A blower door is simply a large door with a fan in it that allows you to
pressurize a home so you can use smoke sticks to find air leaks.
Estimated Cost Savings:
Properly sealing your home can save you 30-40% of your heating and cooling
Sealing up the outside of your home without sealing up the inside, traps
moisture in your walls and can lead to mold growth and wood rot. Sealing
up your home without providing outside air for combustion in gas furnaces,
water heaters, and wood burning fireplaces can lead to air quality problems and
could even allow carbon monoxide to build up in the home.
Reducing air leakage is something that needs to be done for homes in all regions of the
Installation (Getting It Done):
Most people think that tightening up the home means caulking around the
outside of the home. This prevents rain water from getting into your walls
and that's important, but does very little to stop air from leaking into your
home. Tightening up an existing home begins on the inside. The greatest
areas of air leakage in a home are around the top of the foundation and around
penetrations into the attic. You can seal the top of the foundation (rim
joist) with caulk or expanding foam. To seal the penetrations into the
attic, the easiest way is to push back the insulation, and seal
the holes around wiring and plumbing stacks and caulk along to tops of interior
walls. To seal the inside of the house, use a clear caulk around the
window frames where the trim meets the wall and all cracks in the window that
aren't operable. Add weatherstripping to the windows if necessary. Install
foam gaskets on outlets and switches on exterior walls. Use clear caulk along
the basement where it meets the floor. Seal around all ceiling fixtures,
heat registers, medicine cabinets, bath tubs, kitchen cabinets, drain and water
pipes where they enter the wall in kitchen and bath and any other interior wall
penetrations. There are many things you can do to reduce air leakage in your home. However, keep in mind that
professional with the proper training and equipment is best suited to pinpoint
air leakage and to identify and deal with combustion safety problems.
Videos On This Topic:
From EcoBroker International:
From Other Sources:
How to Save by Stopping
Home Air Leaks (1:56) - The Home Depot - Sealing your home is a great way to
help reduce wasted energy and lower your monthly energy bills. Find out
more about sealing, caulking, and weather stripping in this Home Depot video.
Air Sealing and Caulking
Walls (2:00) - Johns Manville -
insulation, it is important to seal any cracks where air and drafts could seep
through. In this video, find out about a couple of common forms of sealants and
how to use them to maximize your home�s energy efficiency.
More Information On This Topic:
Iowa Energy Center: Energy Saving Ideas
Complete checklist of what you can do to save energy in your home and the
order that you should do it in.
Air Seal and Insulate with ENERGY STAR
Iowa Energy Center: Home Tightening, Insulation, and Ventilation