International. Through an explanatory text, Belimo shows the benefits of pressure independent valves as a good solution for the application of heat pump with water source.
In a water source heat pump (WSHP) application, a variable or constant speed pump performs water distribution. The primary function of valves in a WSHP application is to allow a predetermined volume of water to enter each unit through a water-to-coolant coil, a 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 is started. In most applications, it does not require controlling 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:
Dynamically balances the system responding to changes in differential pressure.
Maintains design flow at partial load and during morning startup when all loops become critical
Each terminal receives the required flow, without overflow or underflow
Dynamic balancing allows a mechanic to easily start up a building and eliminates the need to re-roll when modifications have been made to the hydronic system.
Improves overall comfort and saves pumping energy
To select the correct 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 1/2" to 6" with up to 713 GPM. This combination of pressure independent valve and variable frequency drive (VFD) saves pumping energy up to 90% of the time when the building load is less than full.
