Integrity Air Conditioning
Posted on January 20, 2020
In a typical house, almost 50% of total energy use is attributable to heating and cooling, and the attic has a HUGE impact on heating and cooling efficiency.
R-value, infiltration, radiant barriers, ductwork, baffles, foam insulation…Do you ever get the feeling that energy savings is over your head?
Well, it probably is! The attic of any house is certain to be a major target in terms of energy-saving improvements.
Understanding what goes on in the attic will help you appreciate what an experienced professional crew can accomplish to improve energy performance, comfort and savings, while also making your house healthier and more eco-friendly.
More exfiltration (interior air leaking outside) occurs through the attic than anywhere else in the house. This isn’t surprising when you consider how many leakage points there are into the attic and how warm air always wants to rise. The warmest air in the house will always be at the top of the living space.
When this warm interior air leaks out through cracks, gaps and openings near the top of the house, a similar volume of outside air needs to leak in, to avoid causing a vacuum. Exfiltration through the attic, combined with infiltration through lower parts of the house is called the Stack Effect, and it’s a powerful factor in poor energy performance. By creating a more effective attic air barrier, we can minimize the stack effect and start saving energy on heating and cooling.
Bad practice. Instead of exhausting moist air outside the house, this bathroom fan duct is dumping air into the attic. The black stain on the roof sheathing is mold. To fix the problem, energy technicians will connect the duct to a roof-mounted vent.
What happens when warm, moist air from a bathroom shower or from a pot of boiling water on the kitchen stove escapes into the attic and suddenly comes into contact with a cold surface?
The answer is “condensation.” Cold air can’t hold as much moisture as warm air, so when warm interior air leaks into a cold attic, droplets of water accumulate on cold attic surfaces like roof sheathing, rafters, and gypsum board. Wet wood and paper provide a perfect environment for mold to grow.
This problem can get much worse when the duct for a bathroom or kitchen vent fan blows humid air into the attic space rather than outside the house.
To eliminate mold in the attic, air-seal the attic and make sure that all vent fans are ducted directly to the outdoors.
We inspect ductwork as a part of new air conditioning system installation. We can repair or seal ductwork – or install new ductwork, when needed.