In a letter to the ASHRAE 52.2 Standard Setting Project Committee, the Air Conditioning, Heating and Refrigeration Institute (AHRI) has recommended not to adopt ISO 16890 as the air filter test standard for the United States. AHRI is a trade organization whose members produce over 90% of the residential and commercial heating, cooling, water heating, and commercial refrigeration equipment made in North America.
AHRI is involved in establishing certifications and standards to ensure that products perform efficiently, reliably and economically. Their Air-Filtration and Ultraviolet Treatment (AFUVLT) Section is charged with establishing standards for air filtration. They have incorporated the ASHRAE 52.2 method of test in their Standards for residential filtration (Standard 680) and commercial and industrial filtration (Standard 850). In their letter they point out that a great deal of industry expense and effort has been invested to both test filters and to communicate the benefits of using these standards to US residential and commercial customers. The Section believes that adopting ISO 16890 would not be in the best interests of the United States air filter industry or consumers.
They list three reasons not to withdraw ASHRAE 52.2 in favor of ISO 16890.
- ISO 16890 requires an IPA vapor conditioning step. This conditioning requirement would “significantly under-report the performance of many types of filter media and make it impossible to compare air filter product performance.” They point out that Appendix J of ASHRAE 52.2 already provides for conditioning of filters – where appropriate. They go on to state that there is no significant research or a consensus “that media charge removal is appropriate for residential and commercial applications.”
- The US market needs an air filter standard that reflects domestic needs. The vast majority of US HVAC systems use forced air recirculation and ventilation air is only a small fraction of the total air flow. Filtering ventilation air is a much larger concern in other areas of the world. Adopting ISO 16890 “would likely negatively impact filter efficiency and energy usage for domestic residential systems, which have limited space for filtration equipment.” It would also be difficult to change ISO 16890 to reflect the needs of the US market since the United States would only have one vote.
- ASHRAE 52.2 reports the actual filter efficiency in removing particles from 0.3-10 um. ISO 16890 assigns four ePM classifications. PM was created as an outdoor measure for air quality. More research and industry discussion is required “to determine the appropriate way to create an indoor equivalent PM efficiency before the ePM approach is adopted.”
The letter closes by re-emphasizing the AHRI product section support of retaining ASHRAE 52.2. It can be read in it’s entirety here: http://www.ahrinet.org/App_Content/ahri/files/RESOURCES/AHRI-Comments_AFUVLT_52.2.pdf