Direct Drive Vs Belt Drive Attic Fan

Direct drive fans have no power transmission loss since the propeller is directly connected to the motor shaft.

Direct drive vs belt drive attic fan.

That would be quiet but would look like a mess from outdoors. A belt driven fan adds two extra bearings to the system. Where on a belt drive fan the fan motor shaft has a pulley connected by a belt to a second pulley. The second pulley is connected to a shaft that drives the fan propeller.

You have a fan a motor and maybe a coupling. 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. 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.

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. 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. Thus the fan blades will rotate at the same speed as the motor rotates.

Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss. 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. I had a belt drive with a two speed motor years ago.

The motors have two bearings whether the fan is direct drive or belt drive. Belt drive turntables by contrast usually take several seconds to get up to speed. That pulls more air with less fan noise. I think that the belt drive blades can turn slower with a deeper pitch than a direct drive.

Belt drive fans are quieter than direct but still noisy. Direct drive fans require fewer parts and thus usually less maintenance. Sizing a whole house fan. 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.