When you’re running the air conditioner to keep your home cool, outdoor heat is always trying to flow inside. This is known as heat gain, and it most often occurs through leaks in the building envelope, conduction through poorly-insulated walls and ceilings, and solar radiation through glass surfaces.
Here’s a breakdown of the most common heat gain sources, along with ways to control them and save energy.
Windows and Exterior Glass
Radiation through exterior glass represents about 48 percent of heat transfer into a home. You can limit it by planting shade trees and installing exterior window awnings. Indoors, add window coverings with low shading coefficients and close them during the day.
Air Leaks in the Envelope
Leaks in a home’s envelope account for roughly 13 percent of transferred heat. Caulking window frames, weatherstripping doors, and filling in gaps and cracks around any penetrations through the shell with expandable foam spray can curb these gains. Weatherstrip and insulate the attic hatch too, and close the fireplace damper.
A lack of sufficient insulation in the average home’s walls and ceilings accounts for approximately 19 percent of heat transfer to the interior. You can combat this by having extra insulation properly installed. Aim for R-15 in the wall cavities and between R-38 and R-60 on the attic floor.
Conduction Through Ceilings
Heat radiating down through the ceilings from an attic that can reach 160 degrees on hot days represents about 6 percent of total gains in the average home. To lighten your air conditioner’s workload, have a source of attic ventilation installed along with ample exhaust vents.
Internal Heat Generators
Numerous everyday items inside a home generate heat, including lighting, appliances and electronics. These combined sources represent as much as 14 percent of total gains. To limit this, plan activities like cooking, operating the dishwasher and drying laundry at times when it’s cooler outside. Replacing incandescent light bulbs that generate considerable heat with more efficient LED or CFL bulbs can help as well.
To learn more ways to control heat gain in your Monmouth County home, contact the HVAC pros at Aggressive Mechanical Contractors.
Our goal is to help educate our customers in Monmouth County, New Jersey and surrounding areas about energy and home comfort issues (specific to HVAC systems).
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