A water source heat pump (WSHP) system using a cooling tower works by utilizing a closed water loop to move heat, either rejecting it via the cooling tower or using it for heating purposes in other areas of the building.
Understanding the Interconnection
The cooling tower is a critical component in a WSHP system. Here's how it fits in:
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Closed Water Loop: WSHP systems rely on a closed-loop piping system that circulates water between the heat pumps and a central heat rejection/addition device like a cooling tower or boiler.
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Heat Rejection: When individual heat pumps in the system are in cooling mode, they extract heat from the space and transfer it to the water loop. The water, now warmer, flows to the cooling tower.
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Cooling Tower Function: The cooling tower dissipates the heat from the water into the atmosphere through evaporation. The cooled water is then returned to the loop, ready to absorb more heat from the heat pumps.
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Heat Addition (Optional): In heating mode, the heat pumps extract heat from the water loop. If the water in the loop is not warm enough (e.g., during very cold weather), a boiler or other heat source can add heat to the loop.
System Advantages
WSHP systems with cooling towers offer several advantages:
- Independent Units: "Each unit is an independent, packaged system, eliminating the chance of a total system failure. If one unit goes down, the other units are not affected." This distributed approach increases system reliability.
- Energy Efficiency: Heat can be redistributed within the building. For example, if one zone needs cooling while another needs heating, heat can be moved from the cooling zone to the heating zone, improving overall efficiency.
- Zoned Control: Individual heat pumps provide precise temperature control for each zone.
System Components
| Component | Function |
|---|---|
| Water Source Heat Pump | Provides heating and cooling to individual zones by extracting or rejecting heat from the water loop. |
| Cooling Tower | Rejects heat from the water loop to the atmosphere. |
| Water Loop | Closed-loop piping system that circulates water between the heat pumps and the cooling tower/boiler. |
| Boiler (Optional) | Adds heat to the water loop when heating demand exceeds the heat available from the cooling zones. |
| Controls | Manages the operation of the system, including the heat pumps, cooling tower, and boiler. |
