ASHRAE Standard 62-1999, Ventilation for Acceptable Indoor Air Quality, sets minimum ventilation rates and other requirements for commercial and institutional buildings.

Addendum 62g, released recently for a third public review, contains requirements for separating smoking and non-smoking spaces to maintain the status of non-smoking spaces. The proposed addendum exempts high-rise dwellings from pressurization requirements, based on concerns that the requirements are unworkable in these situations, according to Andrew Persily, chair of the committee writing the standard.

The proposed addendum also allows for air cleaning to be used to allow recirculation or transfer from smoking areas to non-smoking areas. It also allows air from environmental tobacco smoke (ETS) areas to be recirculated or transferred to ETS-free areas provided that it has been cleaned or treated to remove the full spectrum of ETS contaminants to levels at or below those of the outdoor air, Persily said.

"However, the standards for rating the necessary air cleaning equipment are still not fully developed, so the use of these technologies will require careful design and application," he said.

The changes are being proposed in response to comments from an earlier public review, Persily said. The public review date for 62g and three other addenda is scheduled for Nov. 30 to Dec. 29, 2001.

Drafts of ASHRAE's proposed addenda are available only during their public review periods. To obtain electronic draft versions of the ASHRAE 62-2001 addenda during the comment period, log on to ASHRAE Online at http://www.ashrae.org/STANDARDS/pubrevdft.htm.