Attic Fan Does Not Run On High Speed

Attic fans can sometimes start making noise whether it s humming rattling or making some other annoying noise.

Attic fan does not run on high speed.

Even at top speed the solar fans only move about half as much air as a conventional electric exhaust fan. The cost of electricity of running a standard attic exhaust fan is probably less thant 5 10 a year. One major variable is the venting if you plan on running the fan on high speed most people do you need to make sure that there is at least enough exhaust venting for high speed setting. Fans are rated by cubic feet of air per minute or cfm.

If it is rotating slowly or not producing a lot of air in the high speed setting you may have a problem with the exhaust or intake. These fans do not run nearly as well as a standard electrical attic exhaust fan which can run into the night while trying to cool the attic. Whole house fan will only run on high speed i have a whole house fan. When running at a high speed setting does the attic fan run hard or sluggishly.

In order to get rid of the hum you need to either operate the fan at a low speed or replace the fan with a new one that has more blades. Parts can come loose or erode from high amounts of fan usage while turning the speed up to high can cause a persistent loud hum. Check the intake for any debris. The attic fan tends to makes a humming noise when it has a few blades and is running at a high speed setting.

A good rule of thumb is to provide one square foot of net free venting area for every 750 cfm.