In order to analyze the actual heating effect and operation performance of a new type of radiant floor heating system coupled with air-source heat pump applied in the northern cold area

a 76-day field test was conducted in an office building for the management of residential area in Tianjin. During the test period

the average temperature of indoor working area was 18.4~21.8 ℃

and the average indoor surface temperature was 22.5~29.1 ℃. More than 90% of indoor LPD1 and LPD2 were in grade I index. The average daily heating capacity and power are 1.5~6.9 kW and 0.6~3.2 kW

respectively; the daily average power consumption is 0.79 kW?h/m2

and the daily average COP is 1.43~3.54. When the temperature difference between the floor surface and the the office area is within 5 ℃

the heat dissipation can still reach 50–100 W/m2. In the coldest test days

the outdoor temperature is -10.1~2.1 ℃

the average temperature in the working area of three indoor test positions is 21.4 ℃

the lowest indoor instantaneous temperature is 16.4 ℃

LPD1 and LPD2 are all in the standard range of grade I and II

which ensures the heating quality. The range of the heating capacity and power of the system is 6.1~10.9 kW and 2.9~3.3 kW

respectively

and the range of COP is 1.91~3.49.