So the days are shorter and the air a bit crisper, and you know winter is not far away. In this post, we here at GAMA Air are continuing a series of tips on making sure your home is as energy efficient as possible. We want you to be comfortable in your home this winter and also help you save money on your energy bills. The last post, Part 6, gave tips on attic insulation but warned against covering soffit vents with insulation. Why?
Natural Attic Ventilation
After adding insulation for warmth to your attic you then need to allow cold air to enter the attic through vents. As odd as it may seem this combination of insulation and cold air flow is crucial to a stable and energy-efficient home. Why?? One reason is to prevent ice buildup on the roof which can cause damage. A natural flow of outdoor winter air into the attic helps keep it cold, preventing snow from melting, then re-freezing at the gutters, and causing a backup of damaging ice. Additionally, appropriate insulation and good air sealing also keep attics cold in the winter by preventing the entry of heat and moist air from below.
A well-insulated attic with natural air flow is also beneficial in summertime because it pushes out the super-hot air, which protects the roof shingles and removes moisture. Also, it reduces heat transfer into your house.
For these reasons, it is critical to never cover attic vents with insulation. It is a common mistake to do so by placing insulation to block the flow of air at the eaves. But NEVER do this. Instead make sure your attic has good airflow.
A note for summertime... the use of attic fans is a good idea IF your attic is well-insulated and the soffit vents are not blocked. An attic fan works by pulling in cooler outside air from the soffit and gable vents and pushing hot air outside. However, if your attic has blocked soffit vents and/or does not have adequate insulation, the fans will suck cool conditioned air from out of the house. This will make your air conditioner work harder and use more energy which will increase your summer utility bill. To prevent this, be sure to follow the tips in this series of posts and ensure your attic is well-insulated with adequate natural air flow.
And a fan in the attic that runs most of the time is not very energy efficient. If you must have some mechanical means of venting air then consider installing a turbine that spins with the breeze and hot air leaving the attic.
For proper installation of attic insulation you need to install rafter vents (also called insulation baffles). These will allow you to completely cover the attic floor out to the eaves for complete coverage and maximum performance. Another benefit of rafter vents is that they ensure the soffit vents are clear and there is a passage for outside air to move into the attic at the soffits and out through the gable or ridge vent.
Installation of rafter vents is easy: just staple them directly to the roof decking. Rafter vents come in 4-foot lengths and 14-1/2 and 22-1/2 inch widths for different rafter positioning. Rafter vents should be placed in your attic ceiling in between the rafters at the point where your attic ceiling meets your attic floor. Once they are in place, you can then place the insulation right out to the very edge of the attic floor. Just be aware that if you use blown insulation you have to be careful to not get insulation into the soffit.
That’s it for this installment. A few final tips for the attic are coming up next! UPDATE: Read Part 8 here!
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