Influence of different building transparent envelopes on energy consumption and thermal environment of radiant ceiling heating and cooling systems

Abstract In this study, the energy consumption and indoor thermal environment of a radiant ceiling heating and cooling system with three types of transparent building envelopes, namely, ordinary insulating glass (OIG), heat reflective insulating glass (HFIG) and triple silver low-e insulating glass (TSIG), were investigated and compared by experiment and simulation. The annual energy consumption and thermal environment distribution of the radiant ceiling system equipped with the three types of transparent envelope in five different climate zones were obtained. The results show that the energy saving rates of HFIG and TSIG windows are -9.78%-48.00% and 8.82%-63.65% in the five climate zones, compared to the OIG window. It is seen that the TSIG window has greater energy-saving potential in both heating dominant and cooling dominant climate zones. In addition, the annual average air temperature of the room with TSIG window is more stable, which means the thermal environment level is better. It is also found that the response of radiant ceiling system to solar heat gain is different in summer and winter. It has a good response to cooling, and it can timely take away the influence of solar heat gain through the radiation heat transfer. Therefore, the indoor thermal environment level of the rooms with different transparent envelopes has little difference during the cooling season. However, as the response of radiant ceiling systems to heating is poor, the indoor thermal environment is greatly affected by the outdoor parameters and varied with the transparent envelopes. Hence, adopting the transparent envelopes with high performance is preferred in the heating dominant zones.