Article by Alison Kartiganer and Bruce Minturn with Vesta Home Performance Retrofitting
Utilities and government are offering a lot of incentives these days on insulation, and many homeowners are taking advantage of them. However, there is one piece of that process, air sealing, which is often neglected but plays a key role in improving the comfort, durability, indoor air quality, and energy efficiency of a home.
Every home has many penetrations between its conditioned space (the living space) and its unconditioned space (such as attics and crawlspaces). Many of these penetrations, or holes, were created during the home’s original construction, while the rest resulted from electrical, plumbing, or mechanical work that happened later. Every one of those holes can let indoor air leak out of the house, carrying with it the energy used to heat or cool it, or let outdoor air leak into the house, carrying with it the undesirable dust and contamination from a crawlspace or attic. When there are holes both low and high in a house, a chimney effect is created, whereby air enters the house from below to replace air leaving the house from above.
Air sealing (and duct sealing for air ducts) is the key to blocking those leaky penetrations. Combined with insulation, air sealing creates a secure boundary around the house which keeps warm air in, while keeping cold, dank, and dusty air out. If you are considering an insulation project, be sure to ask your contractor about air sealing (and duct sealing, if your home has air ducts). To discover how air, energy, and moisture are moving through your home, consult a home performance specialist for a complete home energy assessment.