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ASHRAE Standard 15-2010 establishes safeguards for life, limb, health, and property and prescribes safety requirements. This standard is directed toward the safety of persons and property on or near the premises where refrigeration facilities are located. It includes specifications for fabrication of tight systems but does not address the effects of refrigerant emissions on the environment. This standard applies to: a) the design, construction, test, installation, operation, and inspection of mechanical and absorption refrigeration systems, including heat pump systems used in stationary applications; b) modifications including replacement of parts or components if they are not identical in function and capacity; and c) substitutions of refrigerant having a different designation.

The 2010 edition removes Appendices B and G from and incorporates Addenda a, b, c, d, e, f, g, h, and i into ASHRAE Standard 15-2007. While the user of this document should be familiar with the entire standard, its organization into the following sections allows faster location of information. The topics included in these sections are:

• GENERAL (Sections 1-6): Purpose, Scope, Definitions, Occupancy Classification, Refrigerating System Classification, Refrigerant Classification, Precedence with Conflicting Requirements, Listed Equipment.
• RESTRICTIONS (Sections 7-8): Restrictions on Refrigerant Use, Installation Restrictions.
• DESIGN AND CONSTRUCTION (Section 9): Materials, System Design Pressure, Refrigerant-Containing Pressure Vessels, Pressure Relief Protection, Setting of Pressure-Relief Devices, Marking of Pressure-Relief Devices and Fusible Plugs, Pressure Vessel Protection, Positive Displacement Compressor Protection, Pressure-Limiting Devices, Refrigerant Piping, Valves, Fittings and Related Parts, Components Other than Pressure Vessels and Piping, Service Provisions, Fabrication, Factory Tests, and Nameplate.
• OPERATION AND TESTING (Section 10): Field Tests, General Requirements.

ASHRAE Standard 34-2010 is intended to establish a simple means of referring to common refrigerants instead of using the chemical name, formula, or trade name. It establishes a uniform system for assigning reference numbers, safety classifications, and refrigerant concentration limits to refrigerants. The standard also identifies requirements to apply for designations and safety classifications for refrigerants and to determine refrigerant concentration limits. This standard provides an unambiguous system for numbering refrigerants and assigning  composition-designating prefixes for refrigerants. Safety classifications based on toxicity and flammability data are included along with refrigerant concentration limits for the refrigerants. This standard does not imply endorsement or concurrence that individual refrigerant blends are suitable for any particular application.

The 2010 edition combines Standard 34-2007 and the 37 approved and published addenda to the 2007 edition. Among the key changes incorporated into the 2010 edition are the following:

• Added fourteen refrigerants to Table 2 and one to Table 1.
• Modified the method of calculating the heat of combustion to more closely represent what actually occurs and added an informative appendix with an example calculation.
• Added an informative appendix showing an example of the calculation of the ATEL and RCL for a refrigerant blend.
• Revised the oxygen deprivation limit adjustment for altitude by an adding an intermediate adjustment at 1500 m (4920 ft).
• Added occupational exposure limits for the refrigerants in Tables 1 and 2.
• Extended the rules for numbering refrigerants to include ethene-, butane-, butene-, and propene-based refrigerants.
• Changed the required testing temperature for flammability. All tests previously required at 100°C (212°F) are replaced by testing at 60°C (140°F).
• Added an optional 2L subclass to the existing Class 2 flammability classification, signifying class 2 refrigerants with a burning velocity less than or equal to 10 cm/s.