Direct Drive Vs Belt Drive Attic Fan

Belt drive turntables by contrast usually take several seconds to get up to speed.

Direct drive vs belt drive attic fan.

The motors have two bearings whether the fan is direct drive or belt drive. You have a fan a motor and maybe a coupling. Sizing a whole house fan. Direct drive fans have motor bearings only and on motors typically 7 and a half horsepower and larger those motor bearings are regreaseable so direct drive fans should be designed for acceptable bearing life and.

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. 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. 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.

I think that the belt drive blades can turn slower with a deeper pitch than a direct drive. Direct drive models are the most do it yourself friendly because for most no attic joists need to be cut. This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating. 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.

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. That pulls more air with less fan noise. I had a belt drive with a two speed motor years ago. 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 fans are quieter than direct but still noisy. 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. Greater efficiency is the biggest pro of direct drive fan configurations. Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft.

Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss. That would be quiet but would look like a mess from outdoors. Unlike belt driven fans there s less energy loss because there s a reduced amount of friction as the fan operates. Most whole house fans are relatively easy to install.

Direct drive fans require fewer parts and thus usually less maintenance.