Combined effect of global warming and buildings envelope on the performance of ground source heat pump systems

Abstract

Heating and cooling systems as well as domestic hot water account for over 50 % of the world’s energy consumption. Due to their high thermal performance, ground source heat pump systems (GSHP) have been increasingly used to reduce energy consumption. The thermal performance of GSHP systems strongly depends on the temperature difference between indoor and ground operation temperature. This temperature difference is a function of mean annual air temperature and energy demand for heating and cooling over the year. The thermal load of a building, on the other hand is influenced by the thermal quality of the building envelope (TQBE) and outdoor temperature. Over the time, there is a change in heating and cooling load of buildings due to two reasons; improving the comfort requirements and outdoor temperature change. The overall aim of the current work is to study the impact of climatic changes in combination with TQBE on driving energy of GSHP. This was achieved by comparing the driving energy of the GSHP for different global warming (GW) scenarios and different TQBE. Under climate conditions of selected cities (Stockholm, Roma, and Riyadh), the current study shows that GW reduces the driving energy of GSHPs in cold climates. In contrast, GW increases the driving energy of GSHPs in hot climates. Also it was shown that buildings with poor TQBE are more sensitive to GW. Furthermore, the improvement of TQBE reduces the driving energy more in cold climates than in hot or mild climates.