Abstract
This paper reports the experimental results on the reduced energy consumption and environmental improvement when a window shade filled up with gelled n-paraffin (i.e., phase change material window shade) was installed inside a double-skin facade. The test equipment of a 1/3 office model was exposed to the external climate in summer. The maximum surface temperature of the PCM window shade was 20 K lower than that of window shade made of metal. The improvement in the indoor radiation field was predicted. The equivalent solar radiation transmittance was reduced by up to 38%; thus, the PCM window shade was confirmed to reduce the cooling energy consumption. While the shade temperature was kept constant, the potential of the natural ventilation was measured by the velocity and temperature distribution of the jet that occurred at the upper part of the slit of the double skin. The driving force behind the natural ventilation with the PCM window shade at night found to be 4.0 times that with metal shade. In addition, the amount of heat discharged at night was increased 6.7 times. These results show that construction can be cooled with night purges, and that PCM window shade can reduce the energy consumption to convey air throughout the day.
