Optimal period of record for air‐conditioning outdoor design conditions in different climate zones of China.

An appropriate record period is necessary for calculating outdoor design conditions precisely, for example, the meteorological conditions of a particular location for heating, ventilation and air‐conditioning (HVAC) design purposes. A method for calculating the optimal period of record (OPR) for air‐conditioning outdoor design conditions is given in this study. The combination of standard deviation method (avoiding the OPR being too short) and optimal climate normal (OCN) model (avoiding the OPR being too long) was used to obtain the appropriate record period for the air‐conditioning outdoor design conditions. Especially, the method was examined in five different climate zones to determine its application. The results show that the OPR is in the range of 5–21 years depending on the climates, much less than the current 30‐year record period used for calculating outdoor design conditions. This indicates the 30‐year record period is no longer suitable for calculating air‐conditioning design conditions. The relatively short record period can well reflect the past climate change and support precise meteorological information for the design of air‐conditioning systems. By combining standard deviation and optimal climate normal model methods, a novel method was proposed to calculate the optimal period of record for air‐conditioning outdoor design conditions. The feasibility of the method was proved in five different climate zones in China. The previous study confirmed that the 30‐year record is no longer suitable for calculating the air‐conditioning design conditions and relative shorter record ranging from five to 21 years should be used in different climate zones. [ABSTRACT FROM AUTHOR]