From US DOE, Monday, August 20, 2010:
Last week as part of Vice President Biden’s announcement of 200,000 homes weatherized under the Recovery act, we asked you to send us your questions and comments about the weatherization process. Today, we’re following up with answers experts from the Department’s Weatherization and Intergovernmental Program:
Nationwide, the energy-efficient retrofits that consistently provide the best return on investment involve sealing gaps in the building envelope which allows conditioned air – either heated or cooled – to escape the interior of the home. States in the Northeast region, which on average have an exceptionally high number of heating degree days each season, are particularly susceptible to energy loss through poor air sealing of the building envelope.
These gaps in the building envelope can include joints between materials, gaps around doors and windows, and penetrations for piping, wiring, and ducts. A blower door test can be used identify these gaps and measure the aggregate degree of air infiltration into your home. Retrofit measures such as caulking, weather stripping, gaskets, and duct sealing can be used to seal these gaps and improve the energy efficiency of your home.
Continue reading: Response to Weatherization Questions