What is the function of the evaporator in a vapor-compression refrigeration system?

• A. The evaporator condenses refrigerant and rejects heat.
• B. The evaporator absorbs heat and vaporizes the refrigerant.
• C. The evaporator compresses refrigerant.
• D. The evaporator stores refrigerant.

Answer: (B)

In the vapor-compression cycle, the evaporator is where the cooling happens. It allows the low-pressure refrigerant to absorb heat from the space being cooled and change from liquid to vapor. That heat absorption, or latent heat of vaporization, is what produces the cooling effect, so the refrigerant leaves the evaporator as a low-pressure vapor and proceeds to the compressor to continue the cycle. The other functions belong to different components: condensation and heat rejection occur in the condenser, compression occurs in the compressor, and storing refrigerant isn’t a role of the evaporator.