LISTEN...

Just as heat always flows from hot to cold, air flows from high (positive) pressure areas to a low (negative) pressure areas.

For air flow to occur, there must be:

• A pressure difference between two points
• A path or opening connecting the points.

Significant heat loss in a building may be the result of air leakage. This may show up in one or more of the following ways:

• Poorly sealed installation around windows and doors.
• Cracks and holes at utility penetrations, electrical outlets, and vent openings.
• Poorly sealed attic hatch openings.
• Cracks at framing junctions and plane changes in the building structure.