Attic Fan Belt Vs Direct Drive

Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss.

Attic fan belt vs direct drive.

This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating. It s balance or lack of balance actually which causes most of the noise. Sizing a whole house fan. Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft.

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. 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. A well balanced direct drive is far quieter than belt. The second pulley is connected to a shaft that drives the fan propeller.

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. 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. Most whole house fans are relatively easy to install.

Direct drive models are the most do it yourself friendly because for most no attic joists need to be cut. That would be quiet but would look like a mess from outdoors. There s also no belt residue and these fans cost less to maintain generally speaking because belts don t wear down and break. Greater efficiency is the biggest pro of direct drive fan configurations.

Belt drive fans are quieter than direct but still noisy. It s incredibly hard to balance a belt and pulley system. Both types are available as direct drive with the fan blade attached to the motor and belt drive with.