Ground Source Heat Pumps
Our range of ground source heat pumps are from Lämpöässä, the leading manufacturer of heat pumps in Finland.
Lämpöässä heat pumps have always been the designs which other companies have strived to replicate, and we are the UK’s only approved installer of these systems.
How does a ground source heat pump work?
A ground source heat pump consists of four elements:
- The collector loop
- The Heat Exchanger
- The compressor
- The thermal store
1. The collector loop is placed under the ground in a parallel array similar to an under floor heating system, or via a vertical bore. A mixture of water and antifreeze is pumped through this. As the liquid flows through the underground pipes, it picks up the temperature of the earth around it, typically returning to the heat pump at about 6°C. This temperature remains fairly constant throughout the year, which is why ground source heat pumps provide such an efficient means of heating, even during very cold winter conditions.
2. Once back at the heat pump, the liquid is passed against a heat exchanger. On the other side of the heat exchanger is a refrigerant. This refrigerant boils at -24°C, so 6°C is plenty to make it boil rigorously.
3. The now gaseous refrigerant is squashed back down using a compressor. Whenever you squash a gas you force it to release energy (try this by sticking your finger over the end of a bicycle pump as you push the piston down).
4. The released energy is passed into a thermal store – which is a large body of stored water, causing the water to get hotter. The cycle of collector loop, heat exchange, compression and energy release continues until the water in the thermal store hits the temperature required to heat your radiators and hot water. The cycle then stops until the temperature of the thermal store falls and needs recharging again.
Studies show that approximately 70% of the energy produced from a heat pump comes from under ground. Lämpöässä systems maximise this, as they are monovalent – i.e. they use the heat pump (rather than a separate immersion heater) to provide all of the hot tap water and radiator heat. A well installed Lämpöässä heat pump will typically generate 4kW of heat for every 1kW of electricity that it uses. The ratio of heat to electricity is called the coefficient of performance, or COP. The COP is the standard measure that is used to describe the efficiency of a heat pump.
A typical ground source heat pump could save you between £395 and £2,000 a year, depending
on which existing heating system you are replacing.
[Source: The Energy Saving Trust]
Key benefits of a ground source heat pump
- Can be used for both heating and hot water production
- Provides good levels of efficiency all year round
- Lasts three times as long as a conventional boiler
- Designed to be low maintenance
- Nothing visible from the outside of the property
Control at your fingertips
Lämpöässä systems come complete with web access connectivity, which means that you can control your heating and hot water remotely from wherever you are, via PC, tablet or smart phone. With up to three independently controllable heating circuits, you can set your Lämpöässä system to deliver exactly the level of heat that you want in different areas of your home to ensure absolute comfort, all year round.
Additional renewable technologies
The ground source systems we install can be complemented by a Solar Photovoltaic (also known as Solar PV) array to help provide some of the energy required to run the heat pump. Solar PV panels installed on the roof of your property work by converting energy from the sun into electrical power.
Electricity generated by Solar PV may also be eligible for the government’s Feed in Tariffs (FITs) scheme, where you could be paid for the electricity you generate through solar technology.
It is worth bearing in mind that there is no perfect synergy between the systems, as the time of day when demand from the heat pump is at its highest, happens to be when the solar panels are generating the least energy – i.e. early in the morning or late at night.
Talk to us here at Finn Geotherm if Solar PV is something you are considering as part of your installation and we can refer you to one of our recommended suppliers.
Not to be confused with Solar PV is Solar Thermal, which uses heat from the sun to warm up hot water used for taps, showers etc. As the name suggests, Solar Thermal relies on the sun to provide the heat needed for it to work.
Solar Thermal systems have to be backed up by an immersion heater or conventional boiler to ensure the property’s hot water needs can be met during cloudy or wintry days and that the water warmed by the sun is heated to the required temperature. It cannot provide all of your water heating needs, whereas a heat pump can do this and provide all of your heating at the same time.