Did you know that a professionally sealed home can reduce your heatings and cooling costs by 20% or more? Air sealing can be a lifetime repair!
Many homes have the equivalent of an open window in terms of air leakage, even though all of their windows are completely closed. Conditioned air escapes through small holes, cracks and gaps located throughout a home from the basement to the attic. The combined area of these gaps can easily equal the area of a fully open window.
Small gaps and cracks typically occur wherever one part of your home joins another. The joints that hold the home together are impacted by contractors as well as settling that occurs naturally in a structure. During the construction process, plumbers, electricians and HVAC contractors have to drill holes and create space to complete their job – running electrical wires, installing ductwork, running water lines, etc. These holes are a part of the process, but they need to be sealed upon completion as hundreds of leakage points are created. In addition, when a home settles, the wood starts to shrink and materials expand and contract at different rates. These also creates gaps that need to be sealed.
There are two reasons why air leakage costs homeowners money. One, the air leaving the home is usually “conditioned” air. That means air that was just heated or cooled to provide the right level of comfort in the home. Running the heating or air conditioning systems uses energy which costs money. Excessive leakage means the heating and air conditioning systems will run longer, consumer more energy and increase your electrical bill, not to mention they will struggle to keep you comfortable in your home.
The Stack Effect also causes homeowner money. The Stack Effect simply describes the fact that as hot air escapes out through the top of your home, your home will in turn suck in an equal amount of new, unconditioned, air. Not only did the conditioned air just leave the home, but now heating and air conditioning systems must work double-time to treat the new air.
Although this may sound like a simple process, finding all the points that air can leak out of a home requires specialized equipment, trained professionals and the willingness to access parts of the house that aren’t typically easily accessible. Our experts begin the process with a blower door test.
An “infiltrometer” or blower door fan is placed in the main entry doorway to depressurize the house, i.e. remove air from inside the house. As the fan is running, the technician can move from room to room to detect and diagnose leaks. Although sometimes it is possible to actually see and hear leaks, our technicians use heatless smoke tools to identify drafts and infrared cameras to identify changes in temperature. Both of these tools can pinpoint the source of the leak. Using a software program, the end result of the blower door test also determines your leak rate.
Each strategy is going to depend on the results of the Blower Door Test and calculated leak rate, but typically, we start with the attic as it the location where the most significant amount of air leaks out from a home. In addition, we address basement and crawl space areas as it represents points where unconditioned air enters the home. With this two step approach we can seal the home which will not only save money, but also increase the comfort level inside the home.
Many air leaks and drafts are easy to find because they are easy to feel — like those around windows and doors. But holes hidden in attics, basements, and crawlspaces are usually bigger problems. Sealing these leaks with caulk, spray foam, or weather stripping will have a great impact on improving your comfort and reducing utility bills. Click on the house diagram to see common air leak locations that you should aim to seal.
Homeowners are often concerned about sealing their house too tightly; however, this is very unlikely in most older homes. A certain amount of fresh air is needed for good indoor air quality and there are specifications that set the minimum amount of fresh air needed for a house. If you are concerned about how tight your home is, call us or schedule an energy audit as we use various diagnostic tools to measure your home’s actual leakage. If your home is too tight, a fresh air ventilation system may be recommended.
After any home sealing project, have a heating and cooling technician check to make sure that your combustion appliances (gas- or oil-fired furnace, water heater, and dryer) are venting properly. For additional information on Indoor Air Quality (IAQ) issues related to homes, such as combustion safety, visit EPA’s Indoor Air Quality Web site.