Analysis of the Influence of Airtightness on the Testing Results of Air Purifier Test Cabin

　　Air purifier testing chamberIt is the core equipment for evaluating the key performance of purifiers, such as clean air volume (CADR) and pollutant removal rate. The accuracy of its test results is directly related to product rating and market access. Among various influencing factors, the airtightness of the testing chamber is a fundamental condition for ensuring the reliability of experimental data. Once there is a leak, it will cause systematic deviation in the detection results.

The insufficient airtightness of the test chamber means that there is uncontrolled gas exchange between the chamber and the outside world. When conducting CADR testing, the standard requires pollutants to be circulated by a purifier in a closed space, and the purification efficiency is calculated through a concentration decay curve. If there are small gaps or poor sealing in the cabin, pollutants may escape, and external clean air may infiltrate. This unexpected air flow can artificially accelerate the decrease in pollutant concentration inside the cabin, resulting in artificially high purification efficiency and overestimation of CADR values, thereby erroneously improving product performance levels.

In addition, the degree of impact of airtightness defects on different pollutants varies. For example, gaseous pollutants such as formaldehyde and benzene have smaller molecules and stronger permeability, making them easier to diffuse through small gaps. Their test results are more significantly affected by leaks. Although PM2.5 and other particulate matter are difficult to penetrate, negative or positive pressure fluctuations in the cabin may still cause airflow disturbances, affecting the uniformity of particle distribution and thus interfering with the sampling accuracy of laser particle counters.

To evaluate the impact of airtightness, tracer gas attenuation method is usually used for verification. Inject inert tracer gas (such as SF6) into the cabin and monitor its concentration changes under non purifier operating conditions. In an ideal state, the concentration should remain relatively constant; If significant attenuation is observed, it indicates the presence of a leak. International standards (such as AHAM AC-1) explicitly require that the natural attenuation rate of the test chamber during the test must be below a specified threshold (such as 0.03 h ⁻¹), otherwise the test is invalid.

In conclusion,Air purifier testing chamberThe airtightness is a prerequisite for ensuring the authenticity and fairness of air purifier performance testing. The laboratory should regularly conduct air tightness inspections and maintenance, select high sealing materials, optimize door sealing structures, and establish standardized leak detection processes to ensure the scientific validity of test data.