In a water source heat pump (WSHP) application, a variable or constant speed pump accomplishes water distribution. The primary function of valves in a WSHP application is to allow a predetermined volume of water to enter each unit through either a water-to-refrigerant coil, water-to-air coil, or a water-to-water coil. The valves used are typically on/off control for full design flow when the WSHP starts. In most applications they are not required to control the amount of flow as in a traditional HVAC hydronic system.
The benefits of using a pressure independent valve (PIV) for a water source heat pump:
To select the right pressure independent valve determine the appropriate flow required for your heat pump and select the valve that satisfies this flow. Belimo’s pressure independent valve ranges from ½” to 6” with up to 713 GPM. This combination of pressure independent valve and variable-frequency drive (VFD) enables savings of pumping energy up to 90% of the time when the building load is less than full. More information on pressure independent control valves can be found online.