The book progresses systematically, starting with fundamental concepts like air quality and filtration technology, then moves into detailed analyses of CADR and efficiency testing. It provides a comparative analysis of international standards such as AHAM and ISO, giving readers a clear understanding of their rigor and relevance. From there, it advocates for potential improvements to testing protocols, emphasizing the need for more realistic conditions. This comprehensive approach makes it a valuable resource for anyone seeking to understand the science and technology behind air purification, from engineers and researchers to informed consumers.