Reversing valve

Edit links
Source: Wikipedia, the free encyclopedia.
A reversing valve removed from an HVAC heat pump for replacement

A reversing valve is a type of valve and is a component in a

heating or vice versa. This allows a residence or facility to be heated and cooled by a single piece of equipment, by the same means, and with the same hardware.[1]

Operation

The reversing valve has two states, relaxed (unactivated) versus energized. The energized state is typically achieved by applying 24 volts AC, which is commonly used in

HVAC
equipment. The heat pump can be designed by the manufacturer to produce either cooling or heating with the reversing valve in the relaxed state. When the reversing valve is energized, it will produce the opposite transfer of heat from its relaxed state. For example, a reversing valve installed in such a way as to produce cooling when relaxed will produce heating when energized. Likewise, a reversing valve installed to produce heating when relaxed will produce cooling when energized.

Control

Depending on the construction and use of the heat pump, the reversing valve may be driven by the heat pump through the use of a defrost control board, or it may be driven directly by a thermostat (typically from the "O" terminal of the thermostat).

Replacement

Reversing valves are built into the heat pump by the manufacturer, and must be replaced by an HVAC technician if they fail. Since the valve is an integral part of the sealed refrigerant circuit, proper procedures for recovering and then later refilling the refrigerant must be followed, to prevent its loss into the atmosphere.

See also

References

  1. ^ What is a Reversing Valve
Retrieved from "https://en.wikipedia.org/w/index.php?title=Reversing_valve&oldid=1219450293"