30 May 2005

ENERGY SAVING PERFORMANCE OF DISTRIBUTED HEATING AND COOLING SYSTEM FOR LABORATORY BUILDINGS


An advanced distributed heating and cooling system utilizing small-scale high-performance heat
pumps was designed to replace the central heating and cooling system for the AIST laboratory buildings,
which have a total floor area of 36,100 m2, of which 20,100 m2 is occupied by laboratories. In the old
system, the total primary energy required for hot water was 44 TJ and it was 12 TJ for chilled water, and
39 TJ of primary energy for heating and cooling purpose electricity was used in FY 2001. The new
system is composed of small-sized high-performance heat pumps, with an average coefficient of
performance (COP) of 3.1. The total energy consumption of the new system is estimated to be 61% of
the old system, with a total energy saving of 37 TJ for one year. The total operating cost is estimated to
be 63 %, and a savings of 44.7 million yen for one year. The total CO2 emission is estimated to be 53%, a
reduction of 2,400 tons of CO2 per year. The improvement of the system is caused mainly by the highperformance
small-scale heat pumps and the high-performance total system design that takes laboratory
usage into consideration.