Study on the test accuracy of the high-air-volume purifier under different test chamber volumes

Due to the increasing local purification demand of public spaces during production processes, high-air-volume purifiers (HAVPs) with flow rates >800 m3/h have been increasingly applied in commercial and industrial spaces. Compared with clean air standards in the United States, Europe and other countries, relevant HAVP detection guidelines have not been standardized in most countries, and only Chinese and South Korean standards consider scaling HAVP test chambers. There remains a lack of theoretical and experimental HAVP detection studies. In this study, the airtight test chamber decay method was used, and the chamber size was increased by a ratio of 1:2:3 based on the original volume (30 m3). The effect of the test chamber volume on the HAVP accuracy was evaluated considering the amount of valid data, pollutant uniformity, and air cleaner position. Based on the results, the clean air delivery rate (CADR) deviation varied between 1.4% and 35.7% under the effect of the test chamber volume. The test accuracy was higher for the 60 m3 test chamber, which is more suitable for HAVP testing. A new index based on the CADR–test chamber volume relationship was proposed, revealing that the air cleaner performance can be accurately measured when the equivalent clean air volume ventilation rate varies between 9 and 22 L/h. The upper HAVP detection limit should be considered in standard supplementation. The HAVP flow rate classification in Chinese standards should be refined. The results provide a reference for rapid selection of the appropriate test chamber volume for air cleaners with different flow rates, which facilitates HAVP application in industrial and commercial spaces.