Experimental study of the thermal and energy conservation characteristics of combined phase change material (PCM) room in summer

Combined phase change material room means to lay two different PCMs on building envelops of different orientation. The two PCMs are expected to phase change in summer and winter respectively. In this paper, one combined PCM room and one ordinary room with the same size were built. The thermal characteristics of the two rooms were tested in passive and active conditions. Three cases were designed for the experiment. Case 1 is passive condition. Case 2 is active condition with the air conditioner (AC) working only during the day. Case 3 is active condition with the air conditioner (AC) working only at night. For case 2 and case 3, the set temperature of the AC is 24 ?, 26 ? and 28 ? respectively. During the experiment, indoor air temperature, internal surface temperature, internal surface heat flow and power consumption of the AC were measured. Results showed that in case 1, the PCM room can decrease the indoor air temperature by 6.7 ? during the day. In case 2, when the set temperature of the AC is 26 ? and 24 ?, the PCM room can decrease the indoor air temperature by 0.7 ? and 1.4 ? on average. In case 3, the values are 1.9 ?, 4.5 ? and 5.4 ? respectively when the set temperature is 28 ?, 26 ? and 24 ?. When the set temperature of case 2 is 26 ? and 28 ?, the energy conservation rate is 1.5 % and 36 %, and when the set temperature of case 3 is 28 ?, the value is 1 %. This shows that the combined PCM room has great potential to improve the indoor thermal environment and save energy under both passive and active conditions.