Abstract：

Gives a balanced load distribution between evaporative cooling and radiant cooling based on the engineering design of the composite air conditioning system advanced by the authors. Tests the fresh air system, high temperature chilled water system and indoor temperature and humidity environment on the composite test-bed under summer air conditioning conditions. Test results show that when the air conditioning systems run in the summer of mid-humidity area whose supply water temperature is 19 ℃ and supply air temperature is 17 ℃，the maximum temperature difference is less than 2 ℃ at all sections between 0.1 and 1.1 m above the floor, and the indoor temperature is about 26 to 26.5 ℃ at 1.1 m.The experimental results also show that the gradient of temperature is less than 2 ℃/m between the heights of 0.1 and 1.1 m and is less than 1 ℃/m between 1.1 and 2.7 m, meanwhile indoor relative humidity is in a range of 53.3％ to 65.4％. So the experimental results illustrate that the composite air conditioning system can meet thermal comfort for the occupants. In addition the mean surface temperature of radiant cooling panel is 21.75 to 21.9 ℃, which avoids the risk of condensation, because the ceiling surface temperature is higher than the dew point temperature.