There are four basic types of ground loop systems. The majority of these are closed-loop systems: horizontal, vertical, and pond/lake. The fourth type is the open-loop option.
l Closed Loop System . Most closed-loop ground source heat pumps circulate an antifreeze solution through a closed loop—usually made of a high-density plastic-type tubing—buried in the ground or submerged in water. A heat exchanger transfers heat between the refrigerant in the heat pump and the antifreeze solution in the closed loop. l Open Loop System. This type of system uses well or surface body water as the heat exchange fluid that circulates directly through the heat pump system. Once it has circulated through the system, the water returns to the ground through the well, a recharge well, or surface discharge. This option is practical only where there is an adequate supply of relatively clean water, and all local codes and regulations regarding groundwater discharge are met. Air-to-Water Heat Pumps. An air-to-water (or hydronic) heat pump is a newer heating option that can serve a new construction home or an existing home undergoing remodel. An air-to-water heat pump works like other heat pumps, in that it extracts heat from the outdoor air and uses refrigerant to move it inside the house. However, instead of sending refrigerant to indoor units that heat air to immediately condition the space, an air-to-water heat pump heats water stored in a tank inside your home. The heat can be dispersed throughout your home using low temperature panel radiators, in-floor heat, or fan coils. The system is also capable of very efficiently making hot water for your home.
An air-to-water heat pump may be a complicated upgrade to an existing home with a boiler. However, if you have fuel oil or propane, you might find the operational cost savings worth it.
An air-to-water heat pump system may be appropriate for the following applications but make sure to consult with a contractor: • New homes. • Homes with an existing low-temperature hydronic heating system.
• Replacing a central boiler and/or chiller. • Reducing reliance on propane or fuel oil.
Outdoor Unit
Outdoor Unit
Radiator
Refrigerant Lines
Refrigerant Lines
Infloor Heat
Heat Pump Indoor Unit
Heat Pump Indoor Unit
Water Tank
Water Tank
FIGURE 13: AIR TO WATER – RADIATOR HEAT
FIGURE 14: AIR TO WATER - IN FLOOR HEAT
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ELECTRIC HEAT PUMP CUSTOMER BUYING AND OPERATION GUIDE FOR SINGLE-FAMILY HOMES
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