Honeywell T991A1004 0/100F Prop.Temp. Control 5'Cap

The Honeywell T991A1004 0/100F Prop.Temp. Control 5'Cap is a proportional temperature control for commercial and industrial HVAC systems, including duct heaters, unit heaters, and chilled water systems. This makes use of a capillary bulb that has a long, thin tube inside of it that is filled with a gas or liquid that changes size in response to temperature. Through the tube, this expansion or contraction is transferred to a bellows, which regulates the flow of heating or cooling medium to maintain a constant temperature within a predetermined range. Because of its 5-foot capillary length, which enables remote temperature monitoring, this thermostat is perfect for locations where it must be placed in a central area for optimal temperature control, away from the heating or cooling system.