However there are certain circumstances where they can prove useful.
Do attics need more than 1 attic fan.
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.
Attic ventilation fans could be effective if your home has.
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.
And what s what the tight ceiling claim over and over again.
Such fans cost more to operate than they save in reduced cooling costs so they are not recommended q.
Attic insulation that is less than r 19.
If you want your home air conditioner to cool you better then you might want one or two attic fans.
As wind passes over an externally baffled ridge vent it creates low pressure zone drawing air from the attic.
Without exception you should talk to a professional to determine what your home requires.
Does my home need attic ventilation fans.
If however the ridges are more than 3 feet apart in height only ventilate the higher one or separate the attics.
Also you should buy or build a tight sealing cover if your whole house fan doesn t have one.
I also tested the ceiling fan and the recessed lights didn t have covers and not sealed and there was a 1 4in gap around the lights and still no pull of smoke.
With the attic fan on i tested the outlets and light switches in two rooms below the attic fan and the smoke puffer didn t get pulled.
The moving air tries to cool down all the wood attic framing as without the fan the temperature.
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.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
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.
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.
In some worst case instances attic fans can actually create more problems than they solve.
It may be starting to sound like attic ventilation fans aren t worth the hassle and could cause more problems than they solve.
