For installation on any forced air heating and cooling system
The Air Pressure Switch is designed to control Humidifier operation by sensing changes in air pressure within the furnace plenums when the furnace is in operation.
The Air Pressure Switch can be actuated by a positive pressure, negative pressure or a differential pressure of .05" W C or more.
The Air Pressure Switch contains normally open single throw contacts to supply 120V A C to the humidifier or humidifier transformer when the furnace blower runs.