In which part of the refrigeration system is a dehydrator or dryer installed?

The correct answer indicates that a dehydrator or dryer is installed in the liquid refrigerant line between the receiver and the expansion valve (TXV). This is the appropriate placement for a dryer because its primary function is to remove moisture and contaminants from the refrigerant before it enters the expansion valve and the evaporator coil.

Moisture in the refrigerant can lead to various issues in the cooling system, including corrosion, freeze-ups, and the formation of ice in the expansion valve. By placing the dehydrator in the liquid refrigerant line, it ensures that the refrigerant entering the evaporator is as clean and dry as possible, promoting efficient operation and extending the lifespan of the components in the refrigeration system.

The other sections of the refrigeration system are not suitable for the installation of a dehydrator. For instance, having a dryer in the evaporator coil would expose it to low-pressure conditions and could significantly affect its function. Similarly, a dryer would not be effective in the suction line to the compressor, as it would not adequately filter the refrigerant before it is compressed again. The same applies to the compressor discharge line, as any contaminants or moisture should be removed before the refrigerant reaches this high-pressure point in the system.