What are the three types of feeds in refrigeration systems?

In refrigeration systems, the three types of feeds refer specifically to the methods of delivering refrigerant to the evaporator coil. The choice of DX, overfeed, and flooded encapsulates the various approaches used in different refrigeration applications, each of which influences the efficiency and effectiveness of heat transfer.

DX, or direct expansion, systems allow the refrigerant to expand directly in the evaporator, with the vapor formed from the refrigerant absorbing heat from the environment and ultimately providing cooling. This method is commonly employed in residential and commercial refrigeration units.

Overfeed systems involve a continuous flow of liquid refrigerant that is sprayed into the evaporator. The excess liquid not immediately vaporized in the evaporator circulates back to the receiver. This method is typically used in larger industrial applications where a constant supply of refrigerant is required to meet significant cooling demands.

Flooded systems, on the other hand, maintain the evaporator in a nearly full state of liquid refrigerant to maximize surface contact and heat exchange. This method is often used in large refrigeration setups like cold storage warehouses or ice rinks, as it ensures that the entire evaporator surface is utilized efficiently.

The other options – direct, indirect, and mixed; landed, grounded, and secured; and single, dual