Adding solar attic fans to your home can protect it from seasonal damage and can provide modest energy savings. Running wiring to the attic can be a pain, solar can simplify the problem. In this guide we will discuss what to look for while install your solar attic fan.
Good Soffit Ventilation
Make sure you have good soffit ventilation around the eaves of your roof. You will want approximately 4 sq./ft. of free intake (fresh air) per fan. If you have a grill or holes covering 50% of that intake, then you want to consider 8 sq./ft. per fan. This is also important because you don’t want your solar attic fans to draw air conditioned air through your can lights in your house. You want the fresh cooler air coming in from outside.
Where Do I Place the Fan on my Roof
You want to place your solar attic fan ideally on a slope facing south or west. If you don't want to see the fan from the front, and the front is facing the ideal direction, please use our 40W or 70W tiltable fan. You can install them on the back of the house (facing any desired direction), and then use the tilt panel function to tilt south or west (or "lay flat on the ground"). This will maximize your motor power.
Try to place the fan in the center or "middle" part of the roof. Remember that you want to draw cool outside air from the soffit (or gable) and let it flow through the attic. Although you can use 2 or more fans to enhance the attic ventilation, please make sure you have enough air intake. Also, as mentioned earlier, keep them about 5 feet away from the ridge holes (or other open holes).
Attic Size & Roof Pitch
Now, use this guide to estimate the size of your loft:
If your roof is 2:12 to 5:12, you only need to use the square footage of the house's footprint. For example, if your house is a one-story house of 2000 square feet with a spacing of 5:12, use 2,000 as the square feet of the house for the selection of solar attic fans. If your house is a 2-story 4,000-square-foot house, divide by 2 to get 2,000 as your number.
If your roof is 6:12 or more steep (12:12 at most), you should increase the square footage calculation by 10%. For example, if your house is a 2300 square foot single-storey house, increase the attic space calculation from approximately 230 feet to 2,530 feet. So, if your house is 4,500 floors, divide by 2 to get 2,250, and then add 10% (225) to get 2,475. In this way, you will be able to compensate for steeper and larger roof space. Just remember that each fan has about 4 square feet of free soffit ventilation (fresh air intake). Although we do not want to be accused of selling too many fans, we can use 2 or more fans to improve ventilation performance. Many customers who are on the verge of ventilation specifications will continue to purchase additional fans. We have never heard that the homeowner regrets this decision.
Solar powered attic fans are a simple and effective way to protect your attic from weather related damage. There are many factors to consider when install a solar powered attic fan for your home. Usually we need to take attic area, roof pitch, good soffit ventilation and installation position into consideration.