Conventional Refrigerants-Properties, Advantages and Disadvantages

Contents

1. Abstract
2. Various Refrigerants & Their Properties
   A. Air
   B. Ammonia
   C. Sulphur Dioxide
   D. Carbon Dioxide
   E. Methyl Chloride
   F. Freon-12
3. Overview Table-Comparison of Refrigerants

Abstract

In every refrigeration system, the refrigerant being used plays a crucial role in determining the efficiency and overall performance of the refrigeration system. Some refrigerants might be good as a refrigerant but have major disadvantages like toxicity or they may be harmful to the environment. Therefore, we must have a proper comparison in place to determine the suitable refrigerant to be used in a particular case.

In this article we are going to discuss about the various conventional refrigerants, their properties, advantages and disadvantages. We shall also compare them vis-à-vis.

Various refrigerants & Their Properties

A. AIR

Air is used as a refrigerant in air cycle refrigeration system, mainly used in aircrafts. But, it is a poor refrigerant and Coefficient of Performance (COP) is generally very low (less than 2) in systems using air as a refrigerant.

B. AMMONIA

Ammonia is very widely used refrigerant in the ice-producing cold storage plants. It is suitable for low temperature refrigeration systems due to its very low boiling temperature. Its COP range is quite good (in the range 4-5). But, it is dangerous if it gets leaked, because it is toxic as well as explosive in nature.

C. SULPHUR DIOXIDE

It is suitable for use in domestic refrigeration systems and can work at very low pressures. But it is also very toxic and becomes corrosive in the presence of moisture. It also reacts unfavorably with oil.

D. CARBON DIOXIDE

Carbon dioxide was a widely used refrigerant earlier due to its odourless-ness, non-toxicity and non-explosive-ness.
But, it is not used nowadays because it consumes a lot of work to produce the desired refrigeration effect compared to other refrigerants. It also requires high operating pressure and thus heavy piping and equipments are needed.

E. METHYL CHLORIDE

It is suitable for use in small refrigerators for domestic purposes. But, it is toxic and it is corrosive to Zinc and Aluminum in the presence of moisture.

F. FREON-12

It is most commonly used for domestic refrigerators, air-conditioners and commercial refrigerator plants. It gives good range of COP just like that of Ammonia. Plus, it is almost non-toxic, non-inflammable, colorless and has no smell. It doesn’t react with lubricating oil either.

Overview Table – Comparison of Refrigerants