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Refrigeration Systems 317

Table 11-3C
Refrigerant/Refrigerant Blend Data and Safety Classifications for Common Refrigerants
Quantity of
Refrigerant per
Occupied Space a
Prefix: Chemical Normal Safety lb per Ppm
“R” or . . . No. Chemical Name Formula Boiling Point Group 1,000 ft 3 b by vol g/m 3 b
Methane Series
CFC 11 trichlorofluoromethane CCl 3 F 24°C 75°F A1 1.6 4,000 25
CFC 12 dichlorodifluoromethane CCl 2 F 2 30°C 22°F A1 12.0 40,000 200
HCFC 22 chlorodifluoromethane CHClF 2 41°C 41°F A1 9.4 42,000 150
Ethane Series
CFC 113 1,1,2-trichlorotrifluoroethane CCl 2 FCClF 2 48°C 118°F A1 1.9 4,000 31
HCFC 123 2,2-dichloro-1,1,1-trifluoroethane CHCl 2 CF 3 27°C 81°F B1 c 0.4 1,000 6.3
HFC 134a 1,1,1,2-tetrafluoroethane CH 2 FCF 3 26°C 15°F A1 c 16.0 60,000 250
HFC 152a 1,1-difluoroethane CH 3 CHF 2 25°C 13°F A2 1.2 7,000 20

Quantity of
Refrigerant Blend per
Room Volume a
Refrigerant Normal Safety lb per ppm
No. Composition (Wt%) Boiling Point Group 1,000 ft 3b by vol g/m 3 b

Azeotropes d
500 CFC-12/HFC-152a (73.8/26.2) 33°C 27°F A1 12 47,000 200
502 HCFC-22/CFC-115 (48.8/51.2) 45°C 49°F A1 19 65,000 300
a Quantities are to be used only in conjunction with Section 7 of ASHRAE Standard 15-1994. The basis for the values shown in this table is a single event
in which a complete discharge of any refrigerant system into the occupied space occurs. The quantity of refrigerant is the most restrictive of a minimum
oxygen concentration of 19.5% or as follows:
Group A1, 80% of the cardiac sensitization level for R-11, R-12, R-22, R-113, R-134a, R-500, and R-502; others are limited by levels in which oxygen
deprivation begins to occur.
Group A2 and A3, approximately 20% of LFL (Lower Flammability Limit).
Group B1, 100% of the measure consistent with the IDLH (Immediately Dangerous to Life or Health) value for R-123.
Group B2 and B3, 100% of IDLH value or 20% of LFL, whichever is lower.
2
b To correct for height above sea level, multiply values given in table by [1 2.42 10 6 H] where H is measured in feet, or by [1 7.94 10 h]
where h is measured in kilometers.
c Per ASHRAE Standard 34-1992, this toxicity classification is based on recommended exposure limits provided by chemical suppliers. These ratings are
provisional and will be reviewed when toxicological testing is completed.
d Per ASHRAE Standard 34-1992, azeotropic refrigerants exhibit some segregation of components at conditions of temperature and pressure other than
those at which they were formulated. The extent of segregation depends on the particular azeotrope and hardware system configuration.
Used by permission: Bul. REF-AM-3, ©1995. The Trane Co.
(Text continued from page 312)

See Table 11-3A (ASHRAE) regarding numbers and On September 6, 1987, the European Economic Com-
names of refrigerants. munity and the United States signed a phase-out agreement
See Figure 11-23 for a diagram of refrigerant safety group for the manufacture and use of specific refrigerants con-
classification. The manufacture and use of some specific taining chlorine and bromine in the hydrocarbon molecule
20
refrigerants have been canceled and/or restricted due to because of the effects on the atmosphere’s ozone layer. See
the detrimental effect on the ozone layer. Reference 20, p. 18.1, for a more detailed history of this