1. Designation of Refrigerant
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

2. Designation of Inorganic refrigerants
These are designated by number 7 followed by the molecular weight of the refrigerant (rounded-off).
R 7(molecular weight)
Examples.:
Ammonia: NH3
Molecular weight is 17,
∴ the designation is R 717
2. Carbon dioxide:
Molecular weight is 44,
∴ the designation is R 744
3. Water:
Molecular weight is 18,
∴ the designation is R 718
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

3. Fully saturated, halogenated compounds
Designation of
Fully saturated, halogenated compounds
These refrigerants are derivatives of alkanes (CnH2n+2) such as methane (CH4), ethane (C2H6).
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

4. Chemical Formula Cm Hn Clp Fq
Refrigerants are internationally designated as “R” followed by certain numbers such as R – 11, R – 12, R – 114 etc.
Refrigerants followed by a two digit number indicates that a refrigerant is derived from methane base.
Refrigerants followed by three digit number indicates that refrigerant is derived from ethane base.
Chemical Formula Cm Hn Clp Fq
Chemical formula is correct, when:
Complete numerical designation
R(m-1) (n+1) (q)
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

5. Chemical formula is “Correct”
Example :- Designate: Dichloro-tetrafluro-ethane
  C2 Cl2 F4
Cm Hn Clp Fq
m = 2 n = 0 p = 2 q = 4
n + p + q = 2m +2
= (2 x 2) + 2
 6=6
 Chemical formula is “Correct”
R (m – 1) (n + 1) q
R (2 – 1) (0 + 1) 4
R114
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

6. Balanced, Chemical Formula is Correct
Example : Designate- Dichloro difluro methane
C Cl2 F2
Cm Hn Clp Fq
 m = 1 n = 0 p = 2 q = 2
n + p + q = 2m + 2
= 2 + 2
4=4
Balanced, Chemical Formula is Correct
 R (m – 1) (n + 1) q
R (1 – 1) ( 0 + 1) 2
R012
 R12
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

7. Chemical Formula is correct
Example : Designate – Dichloro-monofluro – methane   
Cm Hn Clp Fq
C H Cl2 F
n + p + q = 2m + 2
= (2 x 1) + 2
4=4
Chemical Formula is correct
R (m – 1) (n + 1) q
R (1 – 1) (1 + 1) 1
R021
R21
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

8. Monochloro – difluro – methane CHCLF
Example: Find the Name and chemical formula of R – 22
R22
R022
R (m – 1) (n + 1) q
m – 1 = n + 1 = q = 2
m= n= q = 2
n + p + q = 2m + 2
1 + p + 2 = (2 x 1) + 2
P + 3 = 4
P=1
Cm Hn Clp Fq
C1 H1 Cl1 F2
Monochloro – difluro – methane CHCLF
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology

9. Tetrafluroethane Example: Find the Name and chemical formula of R134
R (m – 1) (n + 1) q R
m-1= n+1=3 q=4
m=2 n=2 q=4
n + p + q = 2m + 2
2 + p + 4 = (2 x 2) + 2
P + 6 = 6
P=0
Cm Hn Clp Fq
C2 H2 C0 F4
Tetrafluroethane
11/16/2018
V.P.Katekar, Department of Mechanical Engg, S.B.Jain Institute of Technology