How to choose the right refrigerant for the chiller?

High latent heat

Latent heat is the heat required to change the refrigerant from liquid to gaseous. With high latent heat, the refrigerant absorbs more heat from the load; This improves the cooling efficiency of the system. In addition, it reduces the required mass flow and the amount of refrigerant.

Non corrosive, non-toxic and non flammable

Refrigerants must not be toxic or fatal to air conditioning, human health or food. Contact with metal parts such as pipes and compressors shall not cause galvanic corrosion in any form. It must be compatible with non-metallic components such as NBR tubes, O-rings (for sealing purposes). Because the pressure and temperature of the refrigerant inside the compressor are high, it shall not cause explosion or fire in the system and continue its non flammable characteristics.

Compatibility with lubricants

The refrigerant used must be compatible and miscible with the compressor oil (which means that the refrigerant can be easily separated), because there is a greater chance of mixing in the compressor, and the following problems may occur.

·Acid or sludge formation.

·Acid corrosion will reduce the alkalinity in the oil.

·Reduced viscosity leads to insufficient lubrication.

·The oil carbonizes as the temperature increases.

·Compressor damage due to loss of lubricant performance and load-bearing performance.

High density of inhaled gas and low compression ratio.

The high suction gas density at the compressor inlet means that the compressor is smaller and the compressor motor power is smaller. After the refrigerant passes through the evaporator, the expansion rate of the refrigerant gas is not very high, that is, the low expansion of the fluid to the gas.

Cheap and easily available

In case of repair, maintenance or accidental leakage. The refrigerant must be readily available at a reasonable price.

Easily detect leaks

Leakage can be detected by odor, using soap solution at the connection and maintaining the line under pressure for 20 to 30 minutes using a pressure test method to check the pressure drop.