The ventilation roller coaster

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Categories: Codes and Compliance, Guest Author



You might think the current ASHRAE 62.2 Standard is very controversial and the ventilation rate is fixed. A quick look at the history of ventilation indicates the current disagreement over 62.2 Standard is rather calm and the recommended ventilation rate over the years has been up and down like a roller coaster.

Roller coast photoFirst, the ventilation rate (chart these rates on a piece of paper and you will understand the roller coaster reference). In 1836 Tredgold recommended 5 CFM per person; in 1895 ASHVE (later to become ASHRAE) required 30 CFM per person; in 1946 the American Standards Association required 10 CFM per person, as did ASHRAE in Standard 62-1973, the first official ASHRAE ventilation standard. The next ASHRAE ventilation standard, 62-1981 required 5 CFM per person and then 62-1989 required 15 CFM per person (many of you will recognize this as the basis for the BPI Building Airflow Standard). Yes, this is a roller coaster ride.

Second, want to hear about disagreement? Let’s go back to the attempted revision of ASHRAE 62-1989. In 1992 the Standing Standards Project Committee (SSPC 62) was formed to succeed the committee that wrote 62-1989. The SSPC 62 drafted and approved a greatly expanded document and released it for public review in the summer of 1996. During the 90-day public review period, nearly 9,000 comments were received, primarily from the National Association of Home Builders and tobacco interests! After the SSPC 62 volunteer members spent a year responding to this overwhelming number of comments, the ASHRAE board of directors withdrew the public review draft. Shortly after this ordeal, SSPC 62 was split into SSPC 62.1 for commercial buildings and SSPC 62.2 for residential, low-rise buildings. As you probably know, the first 62.2 standard was published in 2003. The acceptance of 62.2, although slow at first, has been widespread and quiet, relatively speaking.

For more information
The Past and Future of Ventilating Dwellings
Publication – ASHRAE 62.2 Standard

by Rick Karg, President
Residential Energy Dynamics (RED)
Member of ASHRAE 62.2 Committee