Researchers are working on a novel geothermal heat pump that makes cost-effective, energy-efficient heating and cooling of buildings a reality. It works by harnessing heat sources from the air or ground.
With funding support from the GEOTeCH project, researchers have used advances made in geothermal heat pump technology to develop the dual-source heat pump (DSHP) unit for heating, cooling and domestic hot water production.
According to the International Energy Agency, buildings are responsible for 30 % of global energy consumption and a substantial percentage of CO2 emissions.
Heating, ventilation and air conditioning systems in particular make up about half of the energy used in buildings. And the sector is expanding, which makes reduced energy consumption and the use of renewable sources even more important.
The DSHP takes advantage of either air or ground heat sources, depending on operating and climatic conditions.
It's able to select the most favourable heat source or heat sink (for heating or cooling, respectively) in a way that allows it to operate as an air-to-water or brine-to-water heat pump.
In winter it can provide hot water for heating buildings, using either the air or the brine from the ground as heat sources.
Alternatively, in summer, it uses the air or brine as a heat sink to provide cooling.
The unit also ensures year-round domestic hot water, which in summer it can generate using the system's condensing waste heat.
The pump is being demonstrated and monitored in four sites across Europe, one of which is UK project partner De Montfort University Leicester (DMU).
Five boreholes have been drilled at DMU in locations where there was enough soft ground to drill down at least 10 metres.
Heat exchangers have been installed in four of the boreholes. In the fifth hole, temperature sensors have been set up to record data on changes in ground temperature.
Data is also being recorded on energy consumption and comfort levels in the demonstration site, which replicates a small domestic building.
Details at: GEOTeCH project website: www.geotech-project.eu/