In summer, insulation performs the same function it does in winter: it resists the movement of heat. During the hot weather months, insulation retards heat gain into the house. In cold weather, conversely, it slows heat loss. While no type of common residential insulation is season-specific, it’s importance and effectiveness may vary according to the time of year and the part of the house where it’s installed.
How Outdoor Heat Gets Indoors
In hot summer weather, solar heat radiates through the roof into the attic. As heat in the attic accumulates, temperatures in that enclosed space may soar as high as 140 degrees. Because heat energy naturally flows from a hot zone into a cooler zone, this reservoir of extreme heat radiates through the ceiling and down into living spaces.
If the floor of an attic is not properly insulated, heat gain from the attic can raise temperatures in rooms below by up to 20 degrees. This causes your air conditioner to run extended cycles to compensate, boosting monthly energy costs and inflicting excessive wear and tear on your A/C.
How Insulation Resists Heat in Summer
During the summer, insulation in the attic helps resist the passage of heat energy downward into the cooler environment in the house. Attic insulation is usually installed between the ceiling joists. Two forms are typically utilized:
- Fiberglass batts are the familiar roll-out blankets of insulation that resembles pink cotton candy. You’ve probably seen the big rolls stacked up at home improvement stores.
- Cellulose insulation is composed of pulverized fragments of treated cloth and paper. The consistency and color resembles snow. Cellulose is usually blown into the attic under air pressure, forming mounds in the spaces between attic joists.
The depth of insulation installed in the attic determines its effectiveness. According to the Environmental Protection Agency, for adequate heat resistance, cellulose insulation should be a minimum of 10 inches deep while fiberglass batts should be at least 14 inches deep.
For more about summer insulation to keep your house cool and efficient, contact the HVAC professionals at Hansberger Refrigeration and Electric Company.
