International. Ashrae announced that its 2013 editions on refrigerant-related standards now incorporate 41 new additions.
Standard 34-2013 contains the 2010 standard and an addition of 36 publications. Some of the changes incorporated in the standard are the following:
- Assignment for classification of designations and safety designations for a new individual compound refrigerant and 14 new refrigerant mixtures.
- Changed the valued refrigerant concentration limits (RCL) of 19 refrigerants listed in the 2010 standard to comply with the most current methodology.
- Changed the flammability safety ratings of four Class 2 refrigerants to Subclass 2L, based on optional combustion rate measurement data.
- Clarified the methodology for performing flammability tests and to determine fractional compositions for flammability tests.
- Updated the methodology by which the heat of combustion is calculated by refrigerant mixtures (provides examples).
- Defined requirements in which applicants must provide evidence of the existence of an azeotropic mixture, if they apply for an R-500 series designation.
Standard 15 contains the 2010 Standard plus five published additions, some of the key changes include the following:
- Clarification on the location requirements for the mechanical ventilation machine room.
- Clarification that design pressure is expressed in terms of relative pressure or gauge pressure (not absolute).
- Drafting to ensure the standard harmonized with section 1101.10 2012 of the International Mechanical Code (IMC).
The book can be purchased in www.ashrae.org/bookstore
