An addendum defining how the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE) ventilation standard would apply to new and existing buildings has been withdrawn from consideration.

The scope of ASHRAE Standard 62-1999, “Ventilation for Acceptable Indoor Air Quality,” under addendum 62b, would have been changed to limit the standard to new buildings, additions and changes to existing buildings specifically identified in the standard.

The addendum was withdrawn because the committee writing the standard determined that the scope should state “what” the requirements of the standard cover, not “when” the requirements are applied, according to committee members.

In addition, the committee determined that the building codes and other regulatory bodies stipulate when to enforce code requirements. If the standard was adopted by such authorities including such stipulation in the scope could result in conflicts within the building code.

The addendum, which has completed two public review, was developed because some of the requirements in the standard were developed with new buildings in mind, said Andy Persily, chairman of ASHRAE SSPC 62.1.

In other business, the committee recommended addendum 62ab for public review. The proposed addendum states that equipment intended to be exhausted shall be provided with means so contaminants do no recirculate into occupied spaces unless the equipment is designed to exhausted indoors.

The committee also began updating the contaminant concentration guidelines that define maximum allowable indoor levels of contaminants.

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