If you mistakenly change from a lower pour point lubricant to a higher pour point lubricant in a refrigeration system, what will be the result?

Correct Answer: Option B — oil may congeal in the evaporator

A higher pour point lubricant thickens or solidifies at warmer temperatures. If introduced into an evaporator, the oil congeals under low-temperature conditions, severely impairing heat transfer and blocking refrigerant flow.