ASHRAE 52.2 is a widely recognized standard for testing air filters, originating from the United States in 1930. It has undergone several revisions, with the latest update in 2007. ASHRAE 52.2 provides a comprehensive framework for evaluating air filter performance, including parameters such as particle removal efficiency, pressure drop, and dust holding capacity. This standard serves as a benchmark for the air filtration industry, ensuring that air filters meet specific criteria for efficiency, safety, and performance.