The fall is perhaps the best season for opening up the windows and letting in the fresh air. But the extreme temperatures in the summer and winter aren't conducive to open windows, so naturally homeowners shut them tight and turn on that HVAC unit to regulate indoor temperatures.
According to the Air Barrier Association, most average 2,500 square-foot homes in the United States have over a half-mile of cracks and crevices — providing an escape route for conditioned air, making the HVAC unit work harder than it needs to. It's no surprise that this increased energy usage can lead to higher monthly energy bills. Similarly, the U.S. Department of Energy reports that random air infiltration through those gaps and cracks is a leading cause of energy loss in homes, accounting for 25 to 40 percent of the energy loss in most residential structures.
So how can homeowners easily save on energy costs while still being comfortable inside, regardless of the temperature outside? The answer is simple: seal those gaps and cracks!
Why air seal
As a veteran of the building and construction industry, I talk a lot about insulation and how important it is to properly insulate a home, but another equally important topic that sometimes gets less attention is how important — and easy — air sealing can be.
Comfort is directly related to maintaining a consistent indoor temperature. During the winter, indoor comfort improves by sealing the gaps and cracks to keep the warm air in and the frigid air out.
The U.S. Environmental Protection Agency estimates that homeowners can typically save up to 20 percent on heating and cooling costs by insulating and air sealing, and that's savings you can take to the bank.
Where to start
A good place to start is to examine the exterior and interior of the home to identify areas where there are gaps in the structure where two building materials meet — this is where air or moisture may be penetrating the building enclosure. By air sealing these gaps and cracks with an insulating foam sealant, homeowners and contractors can easily and efficiently improve indoor comfort and air quality while reducing energy costs. Air leaks are not limited to obvious places like openings around doors and windows, but also include:
Gaps, cracks and holes between the ceiling and the attic, such as along the edges where the ceiling drywall meets framing lumber.
Gaps where the rim joist and sill plate meet the foundation; To identify these areas, look up to where the basement wall meets the underside of the first floor; the rim joist caps the end of the floor joists, forming a box, and the sill plate is where the pressure-treated wood rests on the top of the concrete foundation.
Gaps where pipes and wires go through walls.
Gaps between attics or crawlspaces and the conditioned part of the house.
Keeping out the critters
Unwanted bugs and other pests can enter through these gaps in the building envelope. A quick fix for pest intrusion can be done using an insulating foam sealant that contains a bitter ingredient that will block pests from intruding and keep them outside where they belong. We recently launched a product called GREAT STUFF™ Pestblock to do just this.
Easy as point, spray, seal
Packaged with an easy-to-use straw dispenser, DIYers can pick up a can of GREAT STUFF™ Insulating Foam Sealant from their local home improvement store and fill those pipe penetrations, gaps in the structure where two building materials meet, and any space that allows air to enter or leave the home's enclosure. Experienced DIYers or contractors can utilize a low-pressure spray polyurethane foam, such as FROTH-PAK™ Foam Sealant, from Dow Building Solutions which quickly expands to fill cavities and cracks and becomes tack free in seconds. Just keep in mind the actual cure time will depend on temperature, relative humidity and size of foam the bead.
The bottom line
More and more energy companies across the country are offering homeowner rebates on upgrades completed — providing additional incentive to seal the home's building envelope. Check to see if your local utility company is offering a rebate by visiting the Database of State Incentives for Renewable Energy, and if you're a contractor, bring the information directly to your customers to show that you care about their home and their energy bills.
Gary Parsons joined Dow Chemical Company in 1982 and has spent 29 years in various Dow divisions including manufacturing and research and development. He is a Fellow in Dow Building Solutions Research and Development. Since 2006 he has been the technical leader of the development team specializing in building enclosure energy management products and systems. He has a B.S. degree in Chemical Engineering from the University of Cincinnati. He is also a LEED Accredited Professional.