What can you do about an attic fan that runs all day? I've already raised the thermostat to 110.?

Question

We moved from Indiana and bought a house in North Carolina in Feburary when it was cool. Now that it is warm the fan runs all day everytime the sun shines and it's over 65. I'm sure there's not enough insulation in the attic, but are there any other options besides raising the thermostat on the small & noisey attic fan?

Answer 1

Your situation sounds about normal for N.C. when it is hot. This is especially true if your insulation is not up to par.

Better to let the fan run. The hotter the attic the more you have tow other issues:

1) the air conditioner will have to work harder to cool the house.(And the fan is cheaper to run)

2) the hotter the attic the hotter the roof itself will be. The hotter the roof the shorter the life span before the roof will need to be replaced.

NOTE: I have a home in Virginia and my attic fan is no most of the day. It may come on a few times after the sun sets. There really is a lot of heat up there.

Answer 2

Turn it off during the day.  The thermostat could also be broken.

Answer 3

Is it really 110 degrees up there? If so , you want it to run all day to remove the hot air. Removing the hot air will keep your whole house cooler. If you don't want it running, turn it up or shut it off. If it's really noisy, maybe a new one is worthwhile and may be more efficient.

Answer 4

Well, welcome to North Carolina. You will find that your attic temperature will often exceed 125 F in the summer. The insulation in the attic will not affect the temperature in the attic space. This insulation is to keep the searing summer heat out of your house. Not to keep the attic cool. The attic space is picking up the heat from the uninsulated side of the roof that have shingles on it.  The shingles are probably dark colored and will absorb heat like crazy. That being said.

Ways to cool your attic space:

1. Increase attic ventilation. I know it sounds stupid but the way to reduces the on-time for your fan is to buy a larger capacity fan. It will "do more in less time". If your were able to move more air faster you may have shorten your duty cycle. 10 mins on, off 5 mins, on 12 mins off 8........ect

2. Shade your roof. This is more difficult than it sounds. Deciduous tress can be planted on the southern side of a house to shade it from the rays of the sun but it takes a long time for trees to mature.

3.Reflect the heat. If your roofing material is light colored it will reflect more heat than it absorbs and the attic will not get as hot.

Answer 5

Does it go off at night?  If so, it needs to be on during the day to remove all the heat in the attic.  You might want to think about a more powerful fan... to pull more heat out faster.. thus lowering the temp more quickly.  If it doesn't go off at night... the thermostat is fried in the fan.  Really simple to replace.  Pick it up at Home Depot.  Remember... unplug the fan to replace.