A study on the evaluation of the annual energy consumption for a geothermal heat pump system with open loop and closed loop ground heat exchangers

Heating and cooling systems contribute greatly to the energy consumption and CO₂ emissions of many countries. Ground source heat pumps (GSHP) are promising energy saving systems for residential, commercial or industrial heating or cooling purposes. A method to estimate the energy consumption and CO₂ emission of GSHPs is therefore very eminent. This paper reviews the methodology to calculate the energy consumption and CO₂ emission of GSHPs. The discussed methodology is then used to compare the energy consumption and CO₂ emission of an open-loop and closed-loop GSHP using data from field test. It is observed that the open-loop GSHP saves 28% energy and reduces CO₂ by 28% than the closed-loop GSHP in the cooling season. When used for both cooling and heating purposes in the year, the open-loop GSHP saves about 6% energy and reduces about 6% of CO₂ emission than the closed-loop GSHP.