The public review period for four American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) standards ends August 7. Up for review are Standard 62-1999 (“Ventilation for Acceptable Indoor Air Quality”), Standard 34-1992 (“Number Designation and Safety Classification of Refrigerants”), Standard 34-1997 (“Designation and Safety Classification of Refrigerants”), and Standard 90.1-1999 (“Energy Standard for Buildings except Low Rise Residential Buildings”).

Standard 62, which is designed to set minimum ventilation rates and other requirements for commercial and institutional buildings, has three addenda up for public review. They are:

Addendum V, which adds requirements to ensure that air distribution systems are capable of delivering outdoor air to occupied spaces. The addendum addresses balancing, plenum mixing systems, exhaust duct location, and documentation.

Addendum W, which defines performance criteria for air stream surfaces in ventilation system equipment, duct, and plenums.

Addendum X, which clarifies and adds requirements to ensure that the building envelope does not contribute to IAQ problems. The addendum also calls for design features to minimize attached parking garage vehicle exhaust from entering occupied spaces.

The proposed addendum to Standard 34-1992 is Addedum P, which specifies the data required to determine the flammability classification of a refrigerant. Specific instructions for testing refrigerant blends are included.

The proposed addendum to Standard 34-1997 is Addendum S, which reassigns the safety classification of R-245fa from A1 to B1. This addendum was previously released from the 1992 standard.

Finally, ASHRAE recently released the first proposed changes to Standard 90.1. The 29 addenda proposed are organized by design discipline, and consist of mostly minor editorial changes, according to Lawrence Spielvogel, chair of the standard committee. One such addendum updates the referenced standard for chiller ratings from the previous Air-Conditioning and Refrigeration Institute (ARI) Standard 550-92 to the new ARI Standard 550/590-1998. ASHRAE believes this update allows for better representation of part-load chiller performance.

The proposed addenda for the four standards can be reviewed on ASHRAE’s website,