Final answer:
The evaporator is the component that uses latent heat of vaporization in a heat pump's heating cycle, where the working fluid absorbs thermal energy and vaporizes.
Step-by-step explanation:
The component that uses the latent heat of vaporization in a simple heat pump is the evaporator. In the heating cycle, heat transfer Qc occurs when the working fluid absorbs energy from the colder outdoor air in the evaporator, causing the fluid to turn from a liquid into a gas, leveraging the latent heat of vaporization. Moments later, the compressor raises the temperature and pressure of this gas before it enters the condenser where it releases heat to the indoor space as it condenses back into a liquid. Finally, the liquid is cooled as it flows back through an expansion valve, reducing its pressure and returning it to the outdoor evaporator coils to complete the cycle.