Are Air Vent whole house fans rated for continuous operation?

Air Vent whole house fans are not rated for 24/7 continuous operation year-round.

It should not be a problem to run Air Vent whole-house fans continuously during the summer months. Officially, that would not be classified as "continuous" because true continuous duty fans are rated as such so that they run all the time (24/7/365) which is not the case for Air Vent's whole-house fans. The fan should provide reliable summer service for many years. The thermal cutoff is a UL requirement and provides protection in the event that the rotor locks up and draws too much current. It would shut the motor off.