Is it OK to connect multiple power vents to a single thermostat or single controller?

Multiple power vents should not be connected to the same controller.

Multiple power vents should not be connected to the same controller (thermostat or thermostat/humidistat) because the controller has not been certified through UL to handle more than one power vent. The power vents are only tested and certified under the one-for-one configuration. Any alterations to the power vent will result in the loss of the UL certification for that particular product(s).