Attic Fan Belt Vs Direct Drive

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.

Attic fan belt vs direct drive.

Belt drive fans are quieter than direct but still noisy. Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft. Greater efficiency is the biggest pro of direct drive fan configurations. Sizing a whole house fan.

It s balance or lack of balance actually which causes most of the noise. Where on a belt drive fan the fan motor shaft has a pulley connected by a belt to a second pulley. 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. Direct drive models are the most do it yourself friendly because for most no attic joists need to be cut.

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. 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. There s also no belt residue and these fans cost less to maintain generally speaking because belts don t wear down and break.

That would be quiet but would look like a mess from outdoors. This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating. The second pulley is connected to a shaft that drives the fan propeller. A well balanced direct drive is far quieter than belt.

Attic mounts installed in the roof or exterior wall of the attic blow air directly out. It s incredibly hard to balance a belt and pulley system. Coming to the advantage of this kind of an industrial fan the biggest advantage is greater efficiency.