GSHP Glossary

Borehole
Holes drilled into the Earth, 50m deep and filled with a loop of pipe that collects the energy from the Earth. Boreholes are usually drilled when there is no land area to dig trenches.

Closed-Loop Heat Pump System
A heat pump system that uses a loop of buried plastic pipe as a heat exchanger. Loops can be horizontal or vertical.

Compact Collector
A plastic collector that can be used to collect energy from the ground when used with a heat pump. The Compact Collector is used when the garden/land area is too small to install a "Slinky" ground loop system. (see slinky!)

COP (Coefficient of Performance)
The ratio of heating provided by a heat pump to the energy consumed by the system under designated operating conditions. The higher the COP, the more efficient the system. IE 1kW in to the Heat Pump 4kW out, COP = 1:4

Compressor
The central part of a heat pump system. The compressor increases the pressure and temperature of the refrigerant and simultaneously reduces its volume while causing the refrigerant to move through the system.

Condenser
A heat exchanger in which hot, pressurized (gaseous) refrigerant is condensed by transferring heat to cooler surrounding air, water or earth.

Cycling Losses
The actual efficiency of a heating or cooling system is reduced due to start-up and shut-down losses. Over-sizing a heating or cooling system increases cycling losses. A buffer tank or weather compensation on an open zone on the underfloor heating system reduces cycling.

Geothermal Heat Pump
A heat pump that uses the earth as a heat source and heat sink.

Heat Exchanger
A device designed to transfer heat between two physically separated fluids or mediums of different temperatures.

Heat Pump
A mechanical device used for heating and cooling which operates by pumping heat from a cooler to a warmer location. Heat pumps can extract heat from air, water, or the earth. They are classified as either air-source or geothermal units.

Heat Source
The medium of air, water or earth from which heat is extracted by a heat pump.

Open-Loop Heat Pump System
A heat pump system that uses groundwater from a well or surface water from a lake, pond, or river as a heat source. The water is returned to the environment.

Slinky
Coils of pipe layed in trenches to collect the stable temperature in the Earth. Trenches are generally quite long so a lot of land is required.

Weather Compensation Heating Controls
This type of heating system uses the least fuel. The system monitors the temperature inside and outside the building and delivers the correct amount of heat to the building so the building keeps at a comfortable temperature. It's a very efficient way to heat properties and has been mainly used in commercial buildings or larger properites but is now being used more in domestic dwellings.

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