Belt Drive Vs Direct Drive Attic Fan

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 vs direct drive attic fan.

Belt drive fans are quieter than direct but still noisy. Unlike belt driven fans there s less energy loss because there s a reduced amount of friction as the fan operates. Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss. With a belt drive the fan speed can be easily raised or lowered but there is belt and bearing maintenance to consider with a belt drive there are 2 additional bearings.

Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft. 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. It s balance or lack of balance actually which causes most of the noise. The second pulley is connected to a shaft that drives the fan propeller.

Sizing a whole house fan. Coming to the advantage of this kind of an industrial fan the biggest advantage is greater efficiency. You have a fan a motor and maybe a coupling. Greater efficiency is the biggest pro of direct drive fan configurations.

Where on a belt drive fan the fan motor shaft has a pulley connected by a belt to a second pulley. It s incredibly hard to balance a belt and pulley system. A well balanced direct drive is far quieter than belt. That would be quiet but would look like a mess from outdoors.

Most whole house fans are relatively easy to install. On a direct drive fan as implied by the name the fan propeller is connected directly to the shaft of the motor. Direct drive models are the most do it yourself friendly because for most no attic joists need to be cut. 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.

I fantasized building a small shack outside my house and setting the attic fan in the shack and running a duct up to the attic and through the same vent as an attic fan.