It seems like everyone is going green these days and for good reasons. Not only are you contributing to the preservation of the environment, but in the case of solar attic fans, you’ll be contributing to the preservation of money in your wallet. So if you own the double-disc special edition of An Inconvenient Truth but also live a frugal lifestyle, solar attic fans could be your next must-have purchase.
What is it?
Solar attic fans are the relatively new rivals of conventional powered attic fans. Basically they’re installed to ventilate attics, therefore keeping them cooler in the summer months. Because the fans run off solar power, the sun will jumpstart the DC motor via a small solar panel. Generally, the fans will exhaust air at a rate of 800 to 1200 CFM and will be installed with intake vents to ventilate the attic properly.
The solar attic fan will need to be installed by cutting a hole in your roof, which you may want to contract a professional roofer to do if you’re not completely confident in your hole-cutting abilities. On a roof with standard asphalt shingles, the installation of a solar attic fan does not necessitate the use of caulk or roofing cement. Rather, the shingles should be cut in a manner that laces the fan housing into the shingles. If you do plan to install the fan yourself, take extreme precautions as you don’t want to leave your roof susceptible to leakage.
Several variations of solar attic fans are available on the market today. You can buy ones that are low profile, meaning they don’t protrude far out, or ones that are pitched or high profile, meaning they jut out further to catch more sunlight. Pitched and high profile solar attic fans are ideal for northern facing roofs or locations that are prone to heavy snow loads. Some newer solar attic fans actually allow you to install the solar panel separately from the fan. This feature is helpful because it allows you to place your fan in a discreet part of the roof, perhaps somewhere in the back, while allowing you to place your solar panel on the part of your roof facing south to maximize the amount of sunlight.
Who needs it?
Solar attic fans will obviously cater to environmentalists as they run off of natural energy. Also, if you don’t want to go through the hassle of hiring an electrician to help install your powered attic fan, then you may want to purchase a solar attic fan as its installation does not require the expertise of an electrican.
Also, if there is inadequate attic intake air, as well as poor sealing between the attic and the rest of the home, powered attic fans could potentially suck cool air from the inside of your house into the space of the attic. This could increase the potential for attic moisture problems and increase the risk of backdrafting, which will not be a problem with solar attic fans.
Benefits
The biggest benefit to installing a solar attic fan is that they are fueled by the sun, meaning there is no cost for operation. Therefore, solar attic fans are more affordable to operate than conventional powered attic fans. Furthermore, they do not exhaust hot air, they do not require the services of an electrician, and are, for the most part, extremely quiet (allowing you to hang out in the attic in complete silence, if that’s what you like to do).
Also, the highest amount of ventilation will naturally coincide with when the sun is shining the brightest. Lastly, solar attic fans are fairly sturdy and typically resistant to hail, wind, birds/animals, and other foreign object damage.
Risks
Unfortunately, most solar attic fans will be ineffective unless there is an ample amount of sunshine. Therefore, if it is overcast, humid, or extremely muggy outside, your attic may not be getting any of the cool air it needs. Likewise, if it is partly cloudy outside, your solar attic fan will probably run at a reduced speed. Also, once the sun goes down, your solar attic fan will shut off, failing to remove residual heat from the roof framing lumber, roof sheathing, and attic insulation, which all hold heat long after dusk.
Solar attic fans are also more expensive than conventional powered attic fans (roughly $200 more). However, this cost differential may be made up in the fact that you don’t have to bring in the cost of electrical wiring. Still, if your attic is rather large, you may want to consider purchasing multiple solar attic fans to properly ventilate the large space.
The bottom line
There are both substantial pros and cons to installing solar attic fans. Most people will buy solar attic fans because they feel they a have moral obligation to be environmentally friendly. They just better live in a place where it’s always sunny. Perhaps Philadelphia.
I bought 2-SRS #1250's from sunrisesolar.net. Im in Tx and my attic was getting to 150 degrees, after installing my solar attic fans (did the install myself) my attic temp is now 102-103 on a 100 degree day. That saves me a ton on my electric bill. My most expensive electric bill was $310-$320, now It runs from $140-$199. Yeah for solar attic fans. The electric ones just didnt make $$ cents! You do need 2-of them to lower your bill or 1-unit will get most of the humidity and excessive heat out but may or may not lower your bill. JUST DO IT!! Jet
Jet – November 24, 2009 , 2:56 PM
I bought 2-SRS #1250's from sunrisesolar.net. Im in Tx and my attic was getting to 150 degrees, after installing my solar attic fans (did the install myself) my attic temp is now 102-103 on a 100 degree day. That saves me a ton on my electric bill. My most expensive electric bill was $310-$320, now It runs from $140-$199. Yeah for solar attic fans. The electric ones just didnt make $$ cents! You do need 2-of them to lower your bill or 1-unit will get most of the humidity and excessive heat out but may or may not lower your bill. JUST DO IT!! Jet
Jet – November 24, 2009 , 7:56 PM