ASHRAE ventilation standard provides new design guidance for controlling odor in indoor spaces where smoking occurs. ANSI/ASHRAE Standard 62-2001, Ventilation for Acceptable Indoor Air Quality, sets minimum ventilation rates and other requirements for commercial and institutional buildings.

The design guidance, identified as addendum 62o, was approved for publication at ASHRAE's 2002 Annual Meeting held in Honolulu, June 22-26. The addendum addresses the use of ventilation to control odors from tobacco smoke. It does not address health effects.

The addendum provides a method to allow designers to determine the additional ventilation over what would be provided in a similar non-smoking area, according to Andrew Persily, chair of the 62 committee.

Typically, the increase in ventilation is about 10 to 40 cfm/person over the non-smoking rate in spaces without heavy smoking, he said. The actual increase will depend on the smoking rate and occupancy density of the specific space. The guidance is provided as information only in an appendix that accompanies the standard and is not required for compliance.

In addition, the addendum updates the standard's enforceable requirements. It addresses ventilation in smoking areas by requiring these areas to have more ventilation and air cleaning than comparable non-smoking areas. The section notes that "specific ventilation rate requirements cannot be determined until cognizant authorities determine the concentration of smoke that achieves an acceptable level of risk."

This section also states that air from smoking areas shall not be recirculated or transferred to no smoking areas, Persily said. Also, addendum 62o deletes smoking lounges from a table on outdoor air requirements for ventilation. In the same table, the requirements in spaces where smoking is assumed to occur have been lowered, and a footnote added explaining that the table applies to no smoking areas, according to Persily.

The addendum is subject to a 15-day appeals period to the board of directors. Published addenda to ASHRAE standards are available for free at ASHRAE Online, ASHRAE.