Water-Source Heat Pump
An open loop, also known as a deep ground well, consists of two deep wells: one that supplies water to the heat pump and one that returns water back to the ground. How can you tell if your well is deep enough? The bottoms of deeps wells should be within porous rock-based soil. By contrast, the bottoms of shallow wells are typically within sandy soil. A shallow well is subject to rapid draw down and clogging from loose soil.
A closed loop, also known as a ground loop, uses the ground as the heat source, rather than the water itself. In this system, plastic tubing is placed underground. A mixture of water and glycol (an antifreeze) circulates through the tubing and collects heat from the ground. The heated mixture returns to the heat pump to heat the evaporator coil. A closed loop system can be either shallow and wide (called a horizontal closed group) or deep and narrow (called a vertical closed group). A surface water system is a type of open loop system. This system draws water from an open body of water. Keep in mind, however, that higher maintenance is required to keep the water-to-refrigerant heat exchangers free of fouling from organic materials. Either fresh water-sources or salt-based water sources can be used. We do not recommend salt-based water-sources because barnacles and sea mussels can clog the plumbing system and cause a need for equipment replacement.
A mechanical loop is part of a large system that uses water to remove heat from a commercial air conditioning system. As the air conditioning system removes “waste” heat from indoors, it transfers it into a water loop. This loop is then cooled using a rooftop cooling tower. A water-source heat pump helps the air conditioning system operate more efficiently by tapping into this loop and removing this “waste” heat from the air conditioning system.
A pool/spa loop transfers heat from unheated swimming pools to spas. Because of the large size of a swimming pool, you can transfer enough heat from a swimming pool to warm a spa without noticeable decreasing the swimming pool’s temperature. Specifically, you can use a 50°F (10°C) swimming pool warm a spa to 104°F (40°C).
- Because of their high Coefficient of Performance, heat pumps have very low operating costs.
- Water-source heat pumps operate independently of air temperature.
- The life span of heat pumps is typically ten years.
- Because heat pumps only use electricity to transfer energy and emit no pollution, they are very environmentally-friendly