Experimental study of thermal comfort for direct radiant floor heating system utilizing R22

This paper presents experimental study for direct radiant floor heating system with air-source heat pump utilizing R22. An experimental platform was established, and thermal comfort of the heating system was analyzed from floor temperature, vertical temperature field, relative humidity, operation temperature and average radiation temperature, radiation asymmetry, PMV (Predicted Mean Vote) and PPD (Predicted Percent Dissatisfied). It shows that the indoor heat load can be well met as the output capacity of ASHP runs at 30%. When the heating system steadily runs, thermal comfort is very perfect. Finally calculating the values of PMV and PPD index, the results point out that PMV is about -0.7 ~ -0.17, and PPD is 5.58%~15.49% which could well meet the requirements of thermal comfort in China (PPD =≤ 20%, -1.5 <;PMV<;+1.2).