How Geomaster Geothermal Heat Pumps Work

The geothermal heat pump is one of the most efficient ways to heat and cool your building. These geothermal heat pumps actually pump heat into your home during the heating season and out of your home during the cooling season, using proven technology similar to your average refrigerator.

By utilizing underground piping buried under the earth, geothermal heat pumps have an infinite source of energy. This energy is pumped into your home in the heating season and pumped back into the earth in the cooling season where it is stored. The earth has a near constant temperature at depths below 1400mm or more. Unlike air source heat pumps, the system will have consistent temperatures and capacities.

Studies have shown incredible savings against even the most efficient furnaces and air-conditioning systems. The reason? Fluctuating fuel costs: with the cost of fuels spiralling out of control, geothermal heat pumps look better and better each day. They allow greater savings and comfort in almost all applications.

A Geomaster geothermal heat pump consists of several primary components:


Figure 1 – Cooling

The compressor draws the refrigerant from through tubing in the heat exchanger. This action causes the liquid refrigerant to “evaporate” and become cold (?3ºC). The evaporating refrigerant inside the heat exchanger number 2 cools the water being circulated through the heat exchanger.

In order to move the refrigerant from, it must be raised to a higher pressure by the “compressor”. The compressing causes the refrigerant to become hot (a similar effect occurs with an air compressor and this can be verified by quickly and carefully touching the discharge line).

The hot refrigerant is sent through the tubing inside the condenser. Fluid circulated through the heat exchanger cools the refrigerant and causes it to return to a liquid (condense). Even though the fluid may be warm (25-40ºC) it is cooler than the hot refrigerant (37-70ºC).

The warm liquid leaving the condenser passes through an expansion device which lowers the refrigerant pressure before it returns to repeat the cycle.


A heat pump is merely an air-conditioner with one extra valve that allows the condenser (hot heat exchanger) and evaporator (cold heat exchanger) to reverse places in the winter. Figure 2 shows close-ups of this “reversing” valve and where it is located in the heat pump system. In the cooling mode, the valve slides to a position that permits the hot gas from the compressor to flow through the top port to the left bottom port to the condenser. Thus, the heat pump will act like the air-conditioner described in the previous page. Note the valve permits the refrigerant to travel from the heat exchanger serving inside to the compressor in cooling and from the heat exchanger serving outside to the compressor in heating.

Figure 2 – Reversing valve

In the heating mode the reversing valve slides to a position that routes the hot refrigerant from the compressor through the top port to the heat exchanger (which is now the condenser) through the right bottom port of the reversing valve. Thus the fluid circulated through the heat exchanger will be heated. After passing through the expansion device, the refrigerant enters the evaporator heat exchanger at a low temperature. Because the temperature is so low, heat can be transferred from the ground fluid to the refrigerant inside the evaporator. If the water loop is connected to a correctly sized ground coil, the heating efficiency is exceptionally high compared to conventional air sourced systems. A Geomaster Geothermal Heat Pumps incorporate a piping loop buried in the ground, which is considerably warmer than the outdoor air in the winter. Water is circulated through the loops and the heat pump removes the heat from the water as it circulates through the low temperature water coil inside the home. Since the low temperature coil is relatively warm (it is in contact with the fluid being circulated through the ground), the COP of a Geomaster Geothermal Heat Pump is much higher. Geomaster Geothermal Heat Pumps also provide high efficiency in the cooling season. A heat recovery coil or desuperheater can also be added to heat domestic water with waste heat in the summer and with excess heating capacity in the winter.

Figure 3 – Heating

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