The properties and grouping of refrigerants

(system) #1

REFRIGERANTS:- are heat carriers, used to transfer heat from the cabinet or room to the outside, utilizing the evaporation and condensation processes
The refrigerant used should have the ability to change phase easily from liquid to vapor and then from a vapor back to a liquid again
Refrigerant properties
It should be non poisonous.
- It should be non explosives.
- It should be non corrosive.
- It should be non flammable.
- Leaks should be easy to detect.
- It should be non toxic.

Grouping and classification of refrigerants
Refrigerants have been classified by two different national organizations
a- National Refrigeration Safety Code (NRSC).
The national refrigeration safety code classified the refrigerants into three gropes
Group one: - safest of all refrigerants, it includes
R-11, R-12, R-22, R-500, R-502,
R-503, R-504

Group two:- toxic and some what flammable refrigerants
R-717 Ammonia
R-611 Methyl format
R-40 Methyl chloride
R-160 Ethyl chloride
R-1130 Dichloride ethylene

Group three: - flammable refrigerants
R-600 Butane
R-170 Ethane
R-290 Propane

b- National Board of Fire Underwriters (NBFU).
The national board of fire underwriters classifies the refrigerants (mainly) on their degree of toxicity

11 R- 12 R- R-500