Do Attics Need More Than 1 Attic Fan

If there are not enough soffit gable or ridge vents a powerful attic exhaust fan can pull the air from your home through the ceiling if it is not perfectly sealed off.
Do attics need more than 1 attic fan. Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation. Without exception you should talk to a professional to determine what your home requires. Also you should buy or build a tight sealing cover if your whole house fan doesn t have one. And what s what the tight ceiling claim over and over again.
For more natural exhaustion of the fans air outdoor you may need to increase the attic ventilation to 5 or more attic vents than the common area for proper functionality. Your soffit ventilation actually needs to be considerably more than 336 net square inches to supply a 700 cfm fan system or the fan is going to pull the air it needs through unsealed holes and gaps in the attic floor from the conditioned living space. That paper notes data measured at fsec and elsewhere show that attics with nominal natural ventilation and at least r 19 ceiling insulation do not need powered vent fans. Ideal attic temperatures shouldn t be more than 10 to 20 degrees hotter than outside temperatures.
If your attic soars above 100 degrees and reaches the 150 mark its time to consult. One static vent style is the turbine vent which uses wind to power its enclosed fan all it takes is a light breeze to rotate the blades and suck heat out of the attic view example on the home. Most either come with a programmable thermostat or can be wired to one which will turn the fan on when the attic reaches a set temperature no need for flipping a switch or monitoring the attic. That said air resistance and interference such as vent grates reduces the area of true ventilation.
If you want your home air conditioner to cool you better then you might want one or two attic fans. Such fans cost more to operate than they save in reduced cooling costs so they are not recommended q. In some worst case instances attic fans can actually create more problems than they solve.