Question 47Refrigeration & AC - QMED

The correct answer is A) the frost can be removed by passing hot gas through the coils or energizing defrost heaters with the evaporator fan shut down. Explanation: In a multi-box direct expansion refrigeration system, frost can build up on the evaporator coils over time, reducing the system's efficiency. To remove this frost, the system needs to go through a defrost cycle, either by passing hot refrigerant gas through the coils or energizing defrost heaters. During this defrost process, the evaporator fan should be shut down to prevent cold air from circulating and refreezing the melted frost. Options B and C are incorrect because they do not specify the need to shut down the evaporator fan, and option D is incorrect because the frost buildup actually reduces the refrigeration effect.