Refrigerant Designation Numbering System

The Numbering System was release for general use in 1956 and become an industry standard.

Numbering designation and safety classification of the refrigerants is presented in ASHRAE standard 34-1989.

Method of Designating Refrigerant by number is as Follows :-

1. FIRST DIGIT ON THE RIGHT = NO. OF FLUORINE ATOMS

2. SECOND DIGIT FROM THE RIGHT = NO. OF HYDROGEN ATOMS PLUS ONE

3. THIRD DIGIT FROM THE RIGHT = NO. OF CARBON ATOMS MINUS ONE

4. FOURTH DIGIT FROM THE RIGHT = NO. OF UNSATURATED CARBON – CARBON BONDS IN THE COMPOUND.

For Example :–

R134a :- 

4 = Number of Fluorine Atoms = 4

3 = Number of Hydrogen Atoms + 1 = 3

1 = Number of Carbon Atoms -1 = 1

The  “a” suffix indicated that the isomer is unbalanced by one Atom.

R404A :-

4= 400 Series Denotes Zeotropic Mix

0= Chronological numbering designating the components of the mix but not the % of constituents.

4= Chronological numbering designating the components of the mix but not the % of constituents.

A= Upper case letter Denote Specific Composition.