Why Air Barriers Are So Important In Your Building
Jan 27th, 2012 by admin
Cracks, gaps and holes in the building envelope cause heated or cooled air to leak and unplanned outdoor air to enter the building. The results can be costly and dangerous. HVAC systems have to work overtime and energy is wasted. Pests infiltrate, causing damage and the potential spread of disease. Moisture infiltrates, resulting in humidity and potential mold. And maintaining occupant comfort is nearly impossible as hot and cold spots fluctuate throughout the building.
There are three drivers behind air leakage: stack effect, wind effect and mechanical effect. Stack (or chimney) effect is a buoyancy phenomenon when warm air rises through the building and exerts continuous pressure against the roof and upper parts of the exterior walls. The resulting lower pressure at the bottom of the building pulls in unconditioned air through the gaps in the building envelope. In this scenario, warmed air exfiltrates at the top of the building, resulting in wasted energy as the HVAC system works overtime to keep up with the loss of conditioned air.
Canam Building Envelope Specialists, an affiliate of Tremco Roofing and Building Maintenance, has been a leading provider of air barrier solutions for more than 25 years. To help you understand the building science of stack effect, we’ve produced the following video demonstration.
