Energy Efficiency Audits & Contracting in Maine

Do hot days have to mean hotter nights?

Hot summer days sometimes mean choosing between sweltering nights or the glacial cool of an air conditioner eating a hole in your family’s budget – but it doesn’t have to be this way.  If attic insulation and air sealing are done right, you can sleep better through the summer months, enjoying the pleasures of the season instead of dreaming of the return of cooler weather. 

Infrared Analysis of Hot Ceiling | Evergreen Home Performance | Maine

Problem: Radiant Heat       

Solution: Effective Insulation

As sunlight warms your house, daytime temperatures on your roof can exceed 140ºF. At night, when temperatures usually drop, that absorbed heat is released. If your attic insulation is ineffective, you’ve got a giant low-grade radiator hanging over your head. If you live in a Cape-style home, chances are that your sloping sidewalls and attic knee-walls are also uninsulated, which provides a few more radiant surfaces for your enjoyment.


Stack Effect | Evergreen Home Performance | MaineProblem: Air Leaks

Solution: Air Sealing

The old adage says that heat rises, but the truth is that heat will flow anywhere it’s enticed to go by a difference in air pressure. In winter, cold air (which is denser) wants to push in through tiny leaks and cracks in the lower parts of your heated home, which drives the warm air up and out through similar holes and seams in the upper sections of your house (left). In the summer, this “stack effect” reverses: cool air in your home seeks to get outside through leaks in the basement and rim joists, which pulls that hot attic air inside any way it can - through cracks in the ceiling, ventilated recessed lights, even the joints in your attic where wall studs and beams meet sheetrock or plaster. Stopping the stack effect involves sealing the surfaces wherever those little highways of hot air (or “chases”) are found – usually in your attic and basement.  Whether you're using expanding foam, mastic, or caulking, blocking those chases is essential if you're going to keep unwanted air - cold or hot - out of your living space.