Characteristics Of The Conventional And The New Refrigerants - Mitsubishi Electric QAHV-N560YA-HPB Service Handbook

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[6] Characteristics of the Conventional and the New Refrigerants

1. Chemical property
As with R22, the new refrigerant (R744) is low in toxicity and chemically stable nonflammable refrigerant.
However, because the specific gravity of vapor refrigerant is greater than that of air, leaked refrigerant in a closed room will
accumulate at the bottom of the room and may cause hypoxia.
If exposed to an open flame, refrigerant will generate poisonous gases. Do not perform installation or service work in a con-
fined area.
Composition (wt%)
Type of Refrigerant
Chloride
Safety Class
Molecular Weight
Boiling Point (°C/°F)
Steam Pressure
(25°C,MPa/77°F,psi) (gauge)
Saturated Steam Density
3
(25°C,kg/m /77°F,psi)
Flammability
Ozone Depletion Coefficient
*1
(ODP)
Global Warming Coefficient
*2
(GWP)
Refrigerant Charging Method
Replenishment of Refrigerant
after a Refrigerant Leak
*1 When CFC11 is used as a reference
*2 When CO is used as a reference
2
2. Pressure characteristics
The pressure in the system using R744 is 7 to 14 times as great as that in the system using R22.
Temperature (°C/°F)
-20/-4
0/32
20/68
40/104
60/140
65/149
HWE1517A
R744
(CO )
2
(100)
Single Refrigerant Pseudo-azeotropic
Not included
A1
44.0
-78.4/-109.1
6.30/914
242
Nonflammable Nonflammable
0
1
Refrigerant charging Refrigerant charging
in the liquid state in the liquid state
Available
Saturation Pressure (gauge)
R744 R410A
MPa/psi MPa/psi
1.87/271 0.30/44
3.39/492 0.70/102
5.63/817 1.34/194
- 2.31/335
- 3.73/541
- 4.17/605
- 12 -
HFC type
R410A R407C
R32/R125 R32/R125/R134a
(50/50) (23/25/52)
Non-azeotropic
Refrigerant Refrigerant
Not included Not included
A1/A1 A1/A1
72.6
-51.4/-60.5 -43.6/-46.4
1.557/226 0.9177/133
64.0
Nonflammable
0
2090
Refrigerant charging
in the liquid state
Available Available
R407C
MPa/psi
0.18/26
0.47/68
0.94/136
1.44/209
2.43/354
2.74/399
HCFC type
R22
R22
(100)
Single Refrigerant
Included
A1
86.2 86.5
-40.8/-41.4
0.94/136
42.5 44.4
Nonflammable
0 0.055
1774 1810
Refrigerant charging
in the gaseous state
Available
R22
MPa/psi
0.14/20
0.40/58
0.81/117
1.44/209
2.33/338
2.60/377
GB