Heat Pumps


A heat pump is a device that uses refrigerant and pressure to move heat from one place to another. In a ground source geothermal system, the heat pump moves heat from the ground to the house in the winter, and from the house to the ground in the summer.

Heat Pump | How It Works

The internal components of a heat pump are:
  1. Heat exchanger refrigerant/water evaporator
  2. Refrigerant compressor
  3. Optional domestic hot water exchanger
  4. Refrigerant reversing valve
  5. Heat exchanger and condenser
  6. Expansion valve

Steps in the Operation Process:
  1. The water from the loop field is pumped to the evaporator where it changes state from liquid to vapor. The ground water and refrigerant are independent of each other – they exchange thermal properties within the “exchanger”.
  2. Water absorbs a lot more heat when it changes phases than when it is warmed within a phase. The low pressure liquid refrigerant evaporates at about 32°F within this water heat exchanger and absorbs heat from the water.
  3. Next the compressor raises the pressure from 75 PSI to 265 PSI so that heat can be released in the condenser. The compressor adds some heat to this fluid also.
  4. The compressor warms the refrigerant to 120°F with its increase in pressure to 265 PSI. Higher pressure=higher temperatures.
  5. The warm vapor goes to the heat exchanger where it gives off its heat and then condenses back to a liquid. The refrigerant then passes through the expansion valve where the pressure is reduced and the cycle starts again.


First Heat Pump

1904 – Lardarello, Italy

The heat pump was first described by Lord Kelvin in 1853 and developed by Peter Ritter von Rittinger in 1855. After experimenting with a freezer, Robert C. Webber built the first direct exchange ground-source heat pump in the late 1940s.

The first successful commercial project was installed in the Commonwealth Building (Portland, Oregon) in 1948 by J.D. Krocker, an engineer in Portland, Oregon.                      —More

Ground Source Heat Pump

UMR 7 Series

7 Series

Ground source heat pumps move heat between the building and the loop field. In the winter the heat pump takes the heat out of the loop field and moves it into the home. In the summer the heat pump takes the heat out of the house and moves it into the ground. It is this “exchange” between the building and ground that gives “Geoexchange” its name.

There are three basic types of ground source heat pumps – Water to Air, Water to Water, and Forced Air/Hydronic Combo units.  —More

Air Source Heat Pump

UMR Infinity

Infinity® Variable Speed Heat Pump with Greenspeed™ Intelligence

Air source heat pumps look and are installed outdoors much like regular air conditioners. But unlike an air conditioner, the ASHP will both heat and cool a building.

The outdoor unit is attached to the A-Coil on the furnace inside the house. The ASHP brings the heat from the outside air into the house where it is distributed by the furnace. In the summer, the ASHP reverses and uses the A-Coil on the furnace to absorb the heat from the house so that the unit can dump the heat into the outside air. —More

Heat Pump Configurations

Heat pumps can be configured in many different combinations to meet the unique requirements of each residence or building. —More


Headquartered in Fort Wayne, Indiana, WaterFurnace has been raising the standard on innovation and efficiency since its inception in 1983. To date, over 373,000 WaterFurnace units have been installed across all 50 states and countries around the world. —More