A path toward energy efficiency

What is Weatherization?

The field of weatherization is closely linked to work done in Home Energy Audits. Many of the improvements recommended after an energy audit would fall in the category of weatherization. In the weatherization process two major areas are addressed; insulation and air infiltration. By simply aligning the thermal(insulation) and pressure(air) boundaries on a home we can begin to make drastic reductions in energy use. The larger savings come when we increase the insulation and decrease air infiltration to proper levels now understood through modern building science.

A project we completed in the Elm Heights neighborhood of Bloomington showed a typical case of improvements that can be made. This home, built in the 1950's, was virtually un-insulated with an air infiltration rate far beyond the structure's minimum ventilation rate(MVR). After properly insulating the attic and foundation and cutting the air infiltration in half through careful air sealing, we can expect savings in heating and cooling of 30% or more.

Before and After images of a crawlspace that has been insulated and conditioned.

Typical Weatherization Work

  • Adding insulation to attic and walls
  • Insulating foundation.
  • Caulking or foaming air leaks in house.
  • Insulating hot water pipes.
  • Sealing duct work.

  • Insulating and sealing band joist.
  • Adding weatherstripping to exterior doors.

Common Air Leaks

Conditioned air leaving the house is the most common reason for energy loss. In Indiana we are in a heating climate so typically it is hot air leaving the home which represents energy loss. As warm air rises it looks for bypasses high in the home to escape. This creates conditions for cold air to leak into the house from areas lower in the structure.

During our weatherization work, air sealing is often the first work we perform in an effort to keep conditioned air in the house. This graphic shows some common areas in the home that allow air to travel in and out of the conditioned space.