Final answer:
Based on provided details, the defrost mechanism employed by the heat pump isn't specified, but it likely uses a standard method such as time-initiated temperature-terminated or demand defrost systems.
Step-by-step explanation:
The student is inquiring about the type of defrost mechanism used in a heat pump. Heat pumps typically employ a defrost cycle to prevent the buildup of frost on the outdoor coil, which can impede efficiency and performance. There are several types of defrost systems, such as time-initiated temperature-terminated defrost and demand defrost. Documented information doesn’t specify the defrost method; however, based on the provided information about the heat pump’s components, we can deduce it could be either one of those systems. In heating mode, a heat pump extracts heat from the outdoor air through the evaporator, and after heat transfer, the working fluid is compressed and transferred to the condenser inside the heated space.