Well, I've done it. I cut a hole in the roof today and installed a 10 watt solar powered attic fan. I already have a 10 watt solar powered gable vent fan, (earlier post) but the gable vent fan wasn't quite enough ventilation for the hot attic air. 1 -20 watt fan or 2 -10 watt fans are recommended for my roof size and pitch. My roof it L-shaped and the gable vent fan is installed at the top of the "L". The attic fan I installed today is in the middle of the bottom of the "L". That allows the fan to expel hot air from that section of the attic and pull in fresh air from the north and south gable and soffit vents. Like the gable vent fan, the attic fan has a thermostatic switch controlling when the fan turns on. When the attic air temp rises above 80 degrees the fan switches on and switches off when the temperature falls below 70 degrees. That should allow the fan to run most of the year but stay off in the dead of winter. As I wrote in the gable vent fan post the ideas behind adequate attic ventilation are lower energy costs for cooling,because the temperature differential between the inside and outside temps are lower, as well as slowing the deterioration of the roof from the lower temperatures and lower humidity in the attic. While I was in the attic today I located a spot above our kitchen where I can install our tubular skylight. Look for that post soon! The total time to install was a couple of hours and the cost for the fan was about $320. The fan does qualify for a 30% tax credit for photovoltaic systems.
Here are some links if you are thinking about a solar attic fan:
http://www.solaratticfan.com/ - this is the company that makes the fan.
http://www.infinigi.com/ - this is where I got the fan.
http://www.dsireusa.org/ - Federal and State tax incentives
WOW! I am so happy to read about this Chris! I have been wondering about doing just the same, but sort of shy to as you said "cut a big hole in the roof." I found your blog here when I saw that you were facebook friends with my baby sister Amanda Crandall :-) What a small small world! What a great blog!!!
ReplyDeleteMuch love, Jessica Crandall Shabatura
Hey Jessica,
ReplyDeleteThanks so much for checking out the blog!
Cutting a hole in the roof really isn't that bad, especially if you do it on a sunny day and if you seal the new hole really well. There are complete instructions and a whole tube of silicone sealeant sold with every attic fan. Plus you already have probably 10-15 holes in the roof anyway for all the exising ventilation and plumbing vents,so one more isn't too bad. I'm actually planning on 2-3 more roof penetrations once I get the tubular skylight installed and decide if I like it. ( 1 in the kitchen and 1 in each bathroom)
-Chris