One of the most significant contributors to heat gain in your home—which directly influences your energy bills—is a hot attic. By knowing how to put a stop to heat buildup (using ventilation, reflective insulation and/or a radiant barrier) you can reduce your energy costs and improve the comfort of you upper floors during the cooling season.
During warm weather, an attic can become unbearably hot. It is not uncommon to see temperatures greater than 140 degrees in the summer. This is because of conduction of heat through the roof and the fact that warm air in a home rises and collects in the attic. Unless steps are taken to counter these effects, the overheated attic will make it more difficult to cool the living spaces below and add to utility costs.
First, make sure that your attic is completely separated from your upper floor. Verify that the construction does not have gaps allowing air to pass from your conditioned home to unconditioned attic. A common example of this is unsealed recessed lights in the ceiling of the upper floor. If you are not sure about your home, schedule a home performance assessment with a certified auditor.
A combination of the following solutions can help to cool a hot attic and lower your energy costs:
- Ventilation – Your attic needs a way to exhaust hot inside air and supply a steady stream of fresh incoming air form the outside. A ventilation system in the form of ridge and soffit vents can help to keep your attic space from reaching dangerously high temperatures.
- Reflective insulation – It can also be helpful to have reflective insulation installed. This type of insulation is particularly effective at stopping the flow of heat as it moves downward.
- Radiant barrier – There are several types of radiant barriers, including metal roof shingles, roof sheathing and foil. All reflect radiant heat away from a space. These systems are especially effective if equipment or ductwork is installed in the attic.
A note about powered attic fans
Sometimes we see these units installed to remove hot air from the attic. At the surface this would seem to make sense, but an incorrectly chosen and installed fan can work against a homeowner. The fan creates a negative pressure in the attic and in the wrong set of circumstances can actually pull conditioned air from the rooms below up into the hot attic thereby wasting the efforts of your heating and cooling system.
Paul Wadsworth is the President and Owner of P.K. Wadsworth Heating and Cooling. For 37 years, Paul has been providing heating and cooling services to the Greater Cleveland area. P.K. Wadsworth has been a trusted Cleveland HVAC service company for 75 years. The company understand the area's construction and local heating and air conditioning needs. Paul has an MBA from the University of Michigan and a B.S., Industrial Engineering from Purdue University. He's been President of the Cleveland Air Conditioning Contractors of America and a founding member of the local chapter. Paul was born and raised in Cleveland and has been active in the local community. He resides in Cleveland, Ohio with his wife and two sons.
The opinions and statements contained in this article are for general informational purposes only and are not instructions. Only trained, licensed and experienced personnel should attempt installation/repair. The author assumes no liability for the opinions/statements made in this article. Any individual attempting a repair or installation based on this article does so at their own risk of loss.