My Attic Is Very Hot, is that problem?
There is a lot of confusing information online about saving energy around your house, and plenty of gadgets they would like you to buy. One in particular energy saving myth is if you should try to cool your attic with an attic fan. Options include larger vents, powered fans and even solar powered fans, supposedly saving energy and money. We are going to look at a few items to consider and help you make an informed decision.
Why your attic is hot?
Your attic is designed to separate the hot outdoor roof temperature from the air conditioned area inside your house. A hot attic isn’t automatically a problem. If you don’t have unprotected ductwork or HVAC equipment up there, who cares how hot it gets? After all, your house should have a thick layer of insulation on your attic floor to isolate your hot attic from your cool house. How much insulation is the subject of another topic we will discuss in the future.
Whole House Fan and Attic Fan are Not The Same
First lets take a look at a Whole house fan. Whole-house fans are used to cool a house at night, when the heat of the day has passed and the outdoor temperature has dropped enough to feel comfortable. Whole-house fans are designed to be used in homes which do not have air-conditioning. Think about it, It makes no sense to draw in humid exterior air into a house at night if you run your AC during the day. This saves your AC the additional work load of cooling the air and removing the humidity you brought in the night before.
An attic fan by comparison is very different. This fan is mounted in the attic and works by drawing the air through the soffit or eve vents and out through the roof. In theory this sounds like a, “well of course that will save money” kind of idea. However talk to a few home builders, architects and AC guys and you will hear differing opinions. For instance your attic is design to vent the heat out based on intake and exhaust size vents. If you add a fan to try and draw in cooler air and a higher rate than your soffit vents allow, you may start drawing cool AC air from recessed light vents in your ceiling for instance. This happens as your attic actually starts to build negative pressure with added attic fans.
Of course, not all applications or houses are the same. Before you decided to invest into attic or whole house fans, consult with a trusted contractor, or give W.B. Sanders a call and we can help you improve your house.