Heat pumps work on the basis of constant temperature households. In this, they initially heat the house and then top-up any heat loss on a constant flow basis. They have many sensors that monitor the house, ground loops and outside temperatures. By monitoring outside temperatures they try and predict how much heat the house will require and start supplying that heat before the natural heat loss occurs.
1. The system extracts the natural heat from the earth by pumping a water and glycol mixture through a series of Pipes buried beneath the earth. The warmer temperature underground (typically around 10 degrees Celsius) heats the mixture making it hotter when it comes out of the ground than it was when it went in. The mixture only needs to be heated by 3 or 4 degrees Celsius for the Heat Pump to work.
2. The heated water mixture is then passed to an Evaporator. This uses the warm water mixture to heat a refrigerant liquid. The refrigerant liquid boils at temperatures as low as minus ten (-10) degrees Celsius. The refrigerant liquid then boils into a gas which is passed to a Compressor.
3. The Compressor compresses the gas (law of Thermodynamics) creating heat. Temperatures achieved in the gas can now reach between 75 and 100 degrees Celsius. The gas is then fed through a heat exchanger.
4. The Heat Exchanger then warms the surrounding water, which is part of the central heating/domestic hot water system, thereby providing central heating. As the gas goes through the heat exchanger it slowly cools and condenses back into a liquid. It is then passed back into the ground loop to repeat the process.
There are 3 main parts to the ground source heat pump:
1. The Ground loop piping
2. The Heat pump which incorporates:
Evaporator: takes the heat from the water mixture and transfers it into a gas
Compressor: compresses the gas to get higher temperature
Condenser/heat exchanger: gives the heat to the hot water tank for distribution
3. The Distribution System: under-floor heating or radiators
Home pages of interest in this section are:
- Ground Source Heat Pumps
Pages of interest in this section:
- What is a Ground Source Heat Pump?
- How do GSHP’s work?
- Types of GSHP
- GSHP Efficiencies
- Sizing a GSHP
- How much does a GSHP cost
- GSHP Planning Permission
- GSHP’s versus ASHP’s
- GSHP’s in conjunction with Solar PV
- GSHP’s and ASHP’s in Practice
