How It Works
Many homeowners don’t realize how important a home’s
exterior doors can be. Newer doors often fit and insulate better than older
models. You could save significantly on your heating and cooling costs with a
new energy efficient door.
When selecting doors, consider energy performance ratings.
You may come across doors rated for “U-factor”, “solar heat gain coefficient” and
- U-factor: This rating measures the amount of non-solar
heat that flows through a door. Look for a door with a low U-factor to retain
heat in the winter.
- Solar heat gain coefficient (SHGC): This rating
measures the amount of solar heat that flows through a door. A high SHGC door
is more effective at collecting solar heat during the winter to keep your home
warm. A lower SHGC door transmits less heat, so it’s best at keeping your home
cool during the summer.
- Air Leakage: This rating measures how much air is able
to pass through the door. A low leakage rating is ideal; it lowers heating and
cooling costs by retaining air inside your home.
What Can Go Wrong?
Over time, your doors’ worn out seals can cause efficiency
issues. Conditioned air is able to escape, humidity is able to enter, and water
may leak inside your home. Seals and weather-stripping should be replaced when
you notice any leakage. Wooden doors can crack and splinter over time when
exposed to the outdoors. Exterior doors should be treated or painted to extend
their life and improve efficiency as well as appearance.
Doors come in all sizes depending on their application and
use. They can have a negative impact on your carbon footprint as air exchanges
through leaks. This indirectly produces more carbon dioxide (CO2).
ENERGY STAR® doors can lower energy bills and save money.
Doors can gain and lose heat in any of the following ways:
- Direct conduction through the glass, frame or
- Radiation of heat into and out of the house.
- Air leakage through and around doors.