CODES & STANDARDS

ASHRAE
The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recently announced the publication of the 2010 editions of ANSI/ASHRAE Standard 34, Designation and Safety Classification of Refrigerants, and ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.

Standard 34 describes a method of naming refrigerants and assigns classifications based on toxicity and flammability, while Standard 15 establishes procedures for operating refrigeration equipment and systems.

Among the changes incorporated into Standard 34-2010 are:

• The designation and safety classification of one new single-compound refrigerant and 14 new refrigerant blends.
• The addition of occupational-exposure limits to tables 1 and 2.
• Updated concentration limits and safety classifications for several refrigerants.
• The addition of an optional subclass to the Class 2 flammability classification.
• The introduction of a modified method of calculating heat of combustion.
• The addition of an appendix showing the calculation of acute-toxicity exposure limit and refrigerant-concentration limit for a refrigerant blend.

Among the changes incorporated into Standard 15-2010 are:

• Revised requirements for terminating relief-vent discharge lines.
• The bringing of the standard into alignment with UL 984, Hermetic Refrigerant Motor-Compressors.
• The addition of definitions concerning cascade refrigeration systems.
• Guidance for the protection of positive-displacement compressors in cascade refrigeration systems.

Standard 34-2010 and Standard 15-2010 are sold as a set. The cost is $75 for ASHRAE members and $89 for non-members. To order, contact ASHRAE Customer Service via phone at 800-527-4723 (United States and Canada) or 404-636-8400 or fax at 404-321-5478, or visit www.ashrae.org/bookstore.

ASHRAE also recently announced that, through a funding contract with the U.S. Department of Energy, the I-P edition of ANSI/ASHRAE/IESNA Standard 90.1-2007, Energy Standard for Buildings Except Low-Rise Residential Buildings, will be available as a free downloadable PDF at www.ashrae.org/standard901-2007-free for 18 months, from October 2010.