Jet Fan Attic Fan Operation

At Jet Fan Attic Fans, we sell and install automatic attic fans throughout the Chicagoland area. Learn all about our attic fan operations here.

Automatic

My JET FANS are totally automatic, it goes on and off automatically with a thermostat that is in the attic mounted right next to the fan itself. The thermostat is adjustable, but we recommend leaving it set where it is.

How does an attic fan work?

Your attic fan operation depends on whether your Jet Fan attic fan is your first attic fan or if it’s a replacement. If my JET FAN is your homes first attic fan, our installer would have mounted a master shut off switch just inside the attic access. Just leave that switch on all the time. The fan will only run when it’s needed. If anything ever goes wrong with the fan, you could shut it off with that switch without actually having to crawl all the way into your attic. Switches are located by the attic light if there is one. Normally, either the down position or the left position is the off position for the switch. If your JET FAN is a replacement for an old attic fan, you may have to find the circuit breaker or fuse for it and turn it off that way. If you can get into your attic without too much trouble, you can shut it off by turning the thermostat setting all the way up (clockwise).

When does it Run?

You’ll find that on a hot summer day with sunshine when the high temperature for the day outside gets up to 90 degrees Fahrenheit, the fan will run about 12 hours from 10:00 AM to around 10:00 PM. If it’s not that hot, it may only run for a few hours in the afternoon. When the temperature gets up to 95-100 degrees in the attic, the fan comes on and when it gets back down to 85-90 degrees, it shuts off. Without a JET FAN the attic temperature can soar up to 150 degrees Fahrenheit. 

Humidity

Your Jet Fan installer checked in your attic for signs of excess humidity. If there were any such signs, he would have recommended an optional humidistat that controls the fan regardless of temperature to rid the attic of excess humidity that builds up in the winter months. The adjustable humidistat should already be set at 70% relative humidity.

Safety

Jet Fan attic fans have thermal overload protectors that protect the motor if something where to jam the rotation of the motor. In this case, the motor would try to run, heat up, shut off automatically, and then automatically reset and try to run again. In this situation, the fan should be shut off with the master off switch. In the Chicago area, call JET FAN at 630-834-9165 for service. 

Firestats are included with the thermostat. If the temperature in your attic ever gets up to 180 degrees Fahrenheit, that would indicate that there is a fire in the house. The fan will shut off permanently to avoid spreading the fire.

Attic Fan Maintenance

There is no maintenance with the JET FAN. Just check it once a year in July on a hot day. The JET FAN is very quiet, so listening for it may not be sufficient to verify that it’s working or not. By opening the attic access, you should be able to either see or hear the JET FAN run. You may feel air draft through the access when the fan is on and working. If it is not running when it should be, or if it’s making a funny noise, you need to shut it off. In the Chicago area, call JET FAN at 630-834-9165 for service.

Congratulations, your attic will never get up to 150 degrees again!

For additional information about attic fan operations or if you have any specific questions, visit our FAQ page or call (800) 538-3263.