Air Infiltration FAQs

Does insulation help reduce air infiltration?

Yes. The primary role of wall insulation is to thermally insulate. The air flow resistance is of little benefit to the overall energy performance of a house. Therefore, wall insulation plays an insignificant role in reducing a new home’s air infiltration if modern house construction practices are followed.

Where does air infiltration occur?

Let’s start by looking at which areas of a house are most likely to allow air infiltration. It’s been calculated that over 95% of air infiltration in a new home is from non-insulated sources. Air infiltration primarily occurs in windows, doors, fireplaces, perimeter joints, and ductwork penetrations between conditioned and un-conditioned areas. Wall outlets, which contribute less than 5% to whole house air infiltration, are the primary insulated source of infiltration. Through the simple use of wall outlet gaskets, even that small percentage of loss may be reduced to zero.

What helps reduce air infiltration?

Careful design and selection of building materials along with good workmanship can significantly reduce a new home’s air infiltration rates. Building materials such as building wraps and polyurethane vapor barrier films are specifically designed and installed to reduce air infiltration. Good building practices such as limiting the number of perimeter joints, the use of caulking around window and door framing, and the use of weatherstripping around doors and windows are the most widely used and proven means of reducing air infiltration. All of these materials and practices are part of a “system” approach to reducing air infiltration.

High-performance Fiberglass batt insulation products deliver high thermal performance.

Factory-made batt insulations have been used effectively and with great reliability for over 50 years. In fact, Owens Corning as a quality-conscious ball insulation manufacturer contracts with the NAHB (National Association Of Home Builders) National research Center, Inc. to conduct monthly inspections and thermal testing of our Fiberglass batt insulation products. This NAHB Certification is further assurance that Owens Cornings R-13 Sidewall Batt Insulation and R-21 Sidewall Batt Insulation will consistently provide the claimed thermal perfomance.

Using Fiberglass batt insulation products in conjuction with caulking and weatherstripping materials along with good building practices are reliable methods to keep a new house thermally efficient.