22 May 2008

DEVELOPMENT AND FIELD TESTS OF 75kW CLASS CO2 REFRIGERANT HEAT PUMP


We have developed the air-source CO2 refrigerant heat pump for hot water supply
with a heating power of 75 kW class. The developed heat pump has the largest heating
power as the air-source CO2 refrigerant heat pump in Japan. The performance tests of the
developed heat pump were conducted in the climatic environmental testing room. Heating
power for hot water supply and COPs was measured. The field test of the developed heat
pump was conducted at a tourist hotel with public baths in a semi-cold district, and the
seasonal energy efficiency of the developed heat pump was evaluated. On the basis of the
results, the CO2 emission due to the energy consumption of the developed heat pump in the
semi-cold district is estimated to be 39.9% lower than that of the heavy oil boiler and 16.0%
lower than that of the natural gas boiler. The performance and reliability of the developed
heat pump were verified and the developed heat pump was improved for its
commercialization. Furthermore, the energy measurement of the six commercialized heat
pumps installed in the public bathhouse in a warm district was conducted and the annual
energy efficiency of the commercialized heat pumps was evaluated. On the basis of the
results, the CO2 emission due to the energy consumption of the commercialized heat pumps
in the warm district is estimated to be 45.4% lower than that of the heavy oil boilers and
23.6% lower than that of the natural gas boilers.