Abstract: The measurement accuracy requirement of the national standard for the ambient humidity meter for energy efficiency testing of storage type electric water heaters is ±1%RH, which differs greatly from the requirements of similar foreign standards, and the higher accuracy requires the higher cost of configuring measuring instruments, and the requirements for the use process are relatively strict and expensive. Analyzed the environmental humidity requirements for energy efficiency testing of storage type electric water heaters and pointed out that the influence of environmental humidity on the energy efficiency measurement results can be ignored, and through the analysis of the measurement range and measurement accuracy requirements, combined with the applicable requirements of the CTL resolution, it is determined that an accuracy of ±6%RH can meet the requirements for use, so the accuracy of ±1%RH stipulated in GB 21519—2008 and GB/T 20289—2006 can meet the requirements for use. The requirement that the accuracy is ±1%RH is an obviously unreasonable problem.

Key words: Electric storage water heater, Energy efficiency, Household appliances, Humidity, Measurement, Instrument, Accuracy, Standard