R-134A Physical Properties - Frigidaire LGUB2642LF2 Service Manual

Sealed System

R-134a Physical Properties:

R-134a - Tetrafluoroethane
Refrigerant of choice in automotive industry. Genetron134a replaces CFC12 for air conditioning and refrigeration
systems in commercial residential and industrial applications.
R-12 - Dichlorodifluoromethane
A versatile and widely used refrigerant. Common in reciprocating and rotary type equipment. For all types of appli-
cations, household to industrial. Also employed in some centrifugal designs and in several special
applications.
Chemical formula .................................................................... CF
Molecular weight .................................................................... 102.03
Boiling point at 1 atm. ........................................................... -15.1°F (-26.2°C)
Critical temperature ............................................................... 214.0°F (101.1°C)
Critical pressure, psia. ............................................................ 589.9
Critical density. Ib./cu. tt. ...................................................... 31.97
Liquid density at 80°F (26.7°C). Ib./cu. ft. ........................ 75.0
Heat of vaporization at boiling point,
Btu/lb.°F ...................................................................................... 92.4
Specific heat of liquid at 80°F (26.7°C).
Btu/lb.°F ...................................................................................... 0.341
Specific heat of vapor at constant pressure
(1 atm.) and 80°F (26.7°C), (Btu/lb.°F) ............................... 0.204
*Flammable range, %volume in air. ................................. None
Ozone depletion potential .................................................. 0
Greenhouse warming potential (estimate) ................... 0.285
* Flame limits measured using ASTM E681 with electrically activated kitchen match ignition source per ASHRAE
Standard 34.
Comparative Cycle Performance:
Evaporator temperature = 20°F
Condenser temperature = 110°F
Suction superheat = 30°F
sub-cooling = 10°F
Compressor isentropic efficiency = 65%
Evaporator pressure, psi .............................................. 21.0
Condenser pressure, psi .............................................. 136.4
Compression ratio ........................................................ 4.23
Compressor discharge temperature, °F ................. 188.1
Coefficient of performance ........................................ 2.90
Refrigerant circulation per ton, Ib./min. ................ 3.80
Compressor displacement per ton, cfm. ............... 4.51
Liquid flow per ton, cu. in. /min. ............................... 83.2
Latent heat at evaporator temp., Btu/lb ................ 66.5
Net refrigeration effect. Btu/lb .................................. 52.7
CH F
3 2
Refrigerant
12 22 134a
43.0 18.5
226.3 146.4
4.17 4.86
227.0 178.3
2.79 2.83
2.78 3.00
2.82 4.55
67.4 71.7
90.6 86.9
72.0 66.7
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