Summers in Arkansas can be hot, very hot. Uncomfortably mind-numbingly, nature is trying to kill you hot. Oh, and the humidity sucks too. Fortunately for all of us in the south this summer and last summer weren't as hot as normal. So during our brief respite of summer evil, I decided to put some powered ventilation in our attic space. Naturally, I wanted to try a greener system so I looked at solar powered ventilation fans. We all know that the attic can be a hot space and that the heat in our attic reduces the life of our shingles and reduces the effectiveness of our insulation making cooling systems work harder. Imagine a normal 90 degree day outside, in our attic the temperature could get as high at 150 degrees. This
makes your air conditioner work harder than it needs to. Hence we have ventilation in our attic. Most ventilation that you see is passive. Whirly birds, soffit vents, gable vents, ridge vents, and roof vents are passive cooling systems or a way to get air in and out of the attic space that don't require a power source. AC or DC powered gable fans, whole house ventilators, and powered roof vents are active cooling sources for your attic. I chose to go with a gable mounted solar powered ventilation fan. I have 3 gable vents in our house and I thought it would be a good idea to mount a fan in one of them. I had to build a frame 
surrounding the gable vent, and once that was done the installation was fairly easy. You have to seal as many possible air leaks around the fan housing so it takes a bit of caulking to get it done, but the more leaks you seal the more efficient the fan will be, meaning the more hot air it will push out of your attic. I decided to add a thermostatically controlled swith to the fan so it will only come on once the air temperature is above 80 degrees and will shut off when the temperature is below 70 degrees. This prevents the unit from running in the winter when we don't need it. I put in a 10 watt system. It has a 10 watt solar panel on the roof that powers the fan. the fan can move 850 cfm which is a fair amount of air. I have a larger roof than what is recommended for this fan alone, and am planning on adding a 10 watt solar powered attic fan to supplement this system. I have a T-shaped roof and wanted to spread the work load out so I wasn't pulling hot air from one end of the attic to the other. The system I put in cost about $320. Its definitely more expensive than a traditional gable vent fan, but it qualifies for the 30% federal tax credit and its powered by the sun, and how cool is that!
makes your air conditioner work harder than it needs to. Hence we have ventilation in our attic. Most ventilation that you see is passive. Whirly birds, soffit vents, gable vents, ridge vents, and roof vents are passive cooling systems or a way to get air in and out of the attic space that don't require a power source. AC or DC powered gable fans, whole house ventilators, and powered roof vents are active cooling sources for your attic. I chose to go with a gable mounted solar powered ventilation fan. I have 3 gable vents in our house and I thought it would be a good idea to mount a fan in one of them. I had to build a frame 
surrounding the gable vent, and once that was done the installation was fairly easy. You have to seal as many possible air leaks around the fan housing so it takes a bit of caulking to get it done, but the more leaks you seal the more efficient the fan will be, meaning the more hot air it will push out of your attic. I decided to add a thermostatically controlled swith to the fan so it will only come on once the air temperature is above 80 degrees and will shut off when the temperature is below 70 degrees. This prevents the unit from running in the winter when we don't need it. I put in a 10 watt system. It has a 10 watt solar panel on the roof that powers the fan. the fan can move 850 cfm which is a fair amount of air. I have a larger roof than what is recommended for this fan alone, and am planning on adding a 10 watt solar powered attic fan to supplement this system. I have a T-shaped roof and wanted to spread the work load out so I wasn't pulling hot air from one end of the attic to the other. The system I put in cost about $320. Its definitely more expensive than a traditional gable vent fan, but it qualifies for the 30% federal tax credit and its powered by the sun, and how cool is that!Here are some links if your thinking about attic ventilation:
http://www.dsireusa.org/ - State and Federal tax incentives
http://www.solaratticfan.com/ - the gable vent fan I put in
http://www.infinigi.com/ - a cool online store
I'm glad to hear that you've had such a good experience with the solar attic fan, because I've been trying to decide whether or not it's worth it! I didn't know that it also qualified as a tax credit, so I think I'll be getting one now!
ReplyDelete