EVALUATION THE PERFORMANCE OF LAKE WATER USED AS HEAT SOURCE FOR HEAT PUMP SYSTEM IN A TYPICAL JAPANESE RESIDENT BUILDING
Keywords:
Unutilized energy, Lake-water, Heat pump systems, Heat source potential, Residential buildingAbstract
The surface water, such as lake-water, sea-water, reservoir-water is considered as one kind of
unutilized energy because that they own higher temperature in winter and lower temperature in summer than
the ambient air. The energy saving is expectable when the surface water is employed as the heat source of heat
pump system. This study examines the potential of lake water used as heat source of heat pump system in a
residential building. Annual heating and cooling loads of a typical Japanese residential building were calculated
using thermal net-work model of SMASH. The load calculation results indicate that the heating load dominates
in the residential building. In addition, the heating load tends to decrease and cooling load minimally varies
with the rise in insulation level. The air conditioning is generally operated at low load level in exception of the
occasional high load level at the starting running stage. In comparison with the air source heat pump and air
conditioner, the predicted energy saving effect for lake water heat pump could attain 60-70% and 30-45%
during the cooling and heating periods in different locations, respectively.