Suncourt ZO106 6-Inch Diameter Normally Open Electronic HVAC Air Duct Damper With Power Supply

With electronic duct dampers, an appliance module and any X10 timer, you can reduce your heating/cooling expenses by cutting off airflow to unoccupied rooms during work hours. Or, if you want a room to be a little colder or warmer than the rest of the rooms in the house (i.e. grandma and grandpa's bedroom), any mechanical thermostat can close the damper when a pre-specified temperature is reached.