Water Source Heat Pump
Water source heat pump systems are among the most efficient, economical and environmentally friendly methods to heat and cool buildings. They can be located nearly anywhere within a building to serve individual zones. Water source heat pumps (WSHP) transfer heat from where it is not needed to where it is needed, minimizing the amount of energy required for heating/cooling.
Standard water source heat pump installations include a boiler and a water cooling tower to add and remove energy from the loop. Geothermal heat pump installations use the ground, a body of water, or the aquifer as a heat exchange medium, eliminating the energy consumed by a boiler or water cooling tower.
Types of Installations
Water Cooling Tower/Boiler Loop
A “Boiler/Tower” application uses a simple two pipe water circulating system that adds heat, removes heat or transfers rejected heat to other units throughout the building. The water temperature for heating is usually provided by a natural gas or electric boiler located in a mechanical room.
The condensing water temperature is provided by a cooling tower that dissipates waste heat. This application can be the lowest cost of the loop options available.
Open Loop "Well Water"
“Open Loop” well water systems use ground water to remove or add heat to the interior water loop. The key benefit of an open loop system is the constant water temperature, usually 50°F to 60°F, which provides efficient operation at a low first cost.
Open Loop applications are commonly used in coastal areas where soil characteristics allow reinjection wells to return the water back to the aquifer. Reinjection wells must be approved by the U.S. Environmental Protection Agency.
Horizontal Straight Loop
Horizontal Straight Loops consist of lengths of pipe installed into trenches under the lawn that are dug using a backhoe or excavator, approximately five feet underground and below the frost line. This is the most common installation type and is very economical as long as there is adequate land area available to dig the trenches. In addition to standard trench-based horizontal loops, directional bore loops can be used when the site is heavily wooded or when there is extensive landscaping in place. A machine is used to drill tunnels underneath the yard into which the loop pipes are then installed. This allows the installation to be completed with a minimum of disruption to the existing yard.
Horizontal Coiled "Slinky" Loop
Horizontal Coiled Loops are similar to most common horizontal straight loop installations, except rather than burying straight runs of pipe, the pipe is spread out in flattened, overlapping coils.
This type of loop, also known as a "Slinky Loop", allows for adequate pipe surface area in shorter trenches, allowing it to fit in some areas where horizontal straight loops would be impractical.
Vertical Loops run deep into the ground and are ideal for properties lacking a large area of lawn needed for a horizontal loop. This type of installation is more costly than a horizontal loop, but it has the advantage that it can be used on small lots where not enough open land exists to install a horizontal loop. Vertical loop installations are oftenly used for large commercial buildings, because the land area required for horizontal loops for such large buildings is usually prohibited.
Pond/Lake "Surface Water" Loop
Pond Loops take advantage of an existing body of water located on the property to extract energy with a minimum of excavation work required. The coiled loops are floated into the pond, then filled with liquid and sunk to the bottom. Because there is much less digging required, the pond loop option is often the most cost-effective method for sites that already contain a suitable body of water.