Belt Drive Vs Direct Drive Attic Fan

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.

Belt drive vs direct drive attic fan.

The second pulley is connected to a shaft that drives the fan propeller. Where on a belt drive fan the fan motor shaft has a pulley connected by a belt to a second pulley. Thus the fan blades will rotate at the same speed as the motor rotates. 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.

It s incredibly hard to balance a belt and pulley system. This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating. That would be quiet but would look like a mess from outdoors. Coming to the advantage of this kind of an industrial fan the biggest advantage is greater efficiency.

Direct drive fans require fewer parts and thus usually less maintenance. Belt drive fans are quieter than direct but still noisy. It s balance or lack of balance actually which causes most of the noise. 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.

Direct drive models are the most do it yourself friendly because for most no attic joists need to be cut. A well balanced direct drive is far quieter than belt. Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft. You have a fan a motor and maybe a coupling.

Greater efficiency is the biggest pro of direct drive fan configurations. Most whole house fans are relatively easy to install. Sizing a whole house fan. On a direct drive fan as implied by the name the fan propeller is connected directly to the shaft of the motor.

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.