That would be quiet but would look like a mess from outdoors.
Direct drive vs belt drive attic fan.
Cool attic 24 in steel single belt drive whole house fan.
Where on a belt drive fan the fan motor shaft has a pulley connected by a belt to a second pulley.
Attic mounts installed in the roof or exterior wall of the attic blow air directly out.
However a belt drive fan has power transmission loss due to the friction between the belt and sheaves and due to the drive shaft bearings.
Both types are available as direct drive with the fan blade attached to the motor and belt drive with.
The second pulley is connected to a shaft that drives the fan propeller.
In a direct drive configuration the fan motor that controls the movement of the fan blades is connected either to a shaft or fan axle.
That pulls more air with less fan noise.
Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft.
Coming to the advantage of this kind of an industrial fan the biggest advantage is greater efficiency.
Spruce spruce rb series ventilation fans 8 in steel single direct drive whole house fan.
Sizing a whole house fan.
Belt drive attic fans are usually much quieter than direct drive models though the latter are often cheaper.
Thus the fan blades will rotate at the same speed as the motor rotates.
Direct drive models are the most do it yourself friendly because for most no attic joists need to be cut.
Most whole house fans are relatively easy to install.
I had a belt drive with a two speed motor years ago.
Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss.
For pricing and availability.
Unlike belt driven fans there s less energy loss because there s a reduced amount of friction as the fan operates.
This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating.
Greater efficiency is the biggest pro of direct drive fan configurations.
You have a fan a motor and maybe a coupling.
Belt drive whole house fans that use an integrated pulley system take longer to install but a belt drive unit provides for a smoother and quieter operation.
Belt drive fans are quieter than direct but still noisy.
Direct drive fans require fewer parts and thus usually less maintenance.
When compared to belt drive fans which require belts sheaves and bushings direct drive is just plain simpler and maintenance folks tend to lean toward direct drive for daily maintenance.