Applicability of radiant and convection time series method in coincident design day generation for radiant cooling systems

Previous studies have shown that coincident design day (CDD) can make the calculated design cooling load of an air-conditioning system more rational and accurate. The conversion process of room heat gain to cooling load in radiant cooling systems is different from that in convection cooling systems. The radiant time series method (RTSM) of generating the coincident design day is inapplicable to radiant cooling systems. In this paper, the radiant and convection time series method (RCTSM) is proposed to generate the coincident design day for radiant cooling systems. The relative deviation of design cooling load, computation time for generating coincident design days, and the correct rate are introduced to evaluate the applicability of RCTSM for generating coincident design days. Fifteen room/building characteristic parameters are taken into account to construct 10,000 simulated sample rooms for each city. Compared to the theoretical design cooling load, the relative deviations of design cooling load determined by RCTSM are generally within 7.23 %. RCTSM is suitable to calculate design cooling load and generate coincident design day for radiant cooling systems. The computation time of RCSTM for generating coincident design day is less than one of sixty-third of that of heat balance method. RCTSM can significantly enhance the efficiency in generating coincident design day. The correct rates of the coincident design days generated using RCTSM is higher than those using heat balance method. These results indicate that RCTSM is more suitable to generate the coincident design days for radiant cooling systems than heat balance method.