Why is the refrigerating effect always a lower value than the latent heat?

The refrigerating effect is defined as the amount of heat absorbed by the refrigerant during the phase change from liquid to vapor in the evaporator. This effect is always lower than the latent heat because the process of refrigeration involves not just the latent heat of vaporization, but also other factors that result in a loss of effective cooling capacity.

Specifically, the heat that is required to cool the refrigerant from the compressor discharge temperature down to the evaporating temperature must be taken into consideration. This cooling step takes away a portion of the energy that could otherwise contribute to the refrigerating effect. As a result, the effective refrigerating capacity available for heat absorption becomes lower than the latent heat capacity of the refrigerant alone.

Thus, the difference arises because the refrigerating effect is a net value, factoring in the cooling of the refrigerant after it leaves the compressor and before it enters the evaporator, thereby leading to the conclusion that it is indeed lower than the latent heat value.