NATE Air Conditioning and Heat Pumps Practice Exam

By which method do heat pumps primarily transfer heat during the winter?

1. Absorption

2. Conduction

3. Convection

4. Refrigeration cycle

The correct answer is: Refrigeration cycle

Heat pumps primarily transfer heat during the winter using the refrigeration cycle. This method involves the absorption of heat from the outside air or ground and transferring it indoors even in cold conditions. The refrigeration cycle operates by circulating a refrigerant through a series of components including an evaporator, compressor, condenser, and expansion valve. In winter, when the outdoor temperature is low, the evaporator coil absorbs heat from the outside air; despite the cold air, there is still some heat energy present that can be extracted. The refrigerant, which has a low boiling point, evaporates as it absorbs this heat. The vaporized refrigerant is then compressed by the compressor, which raises its temperature and pressure. This high-temperature, high-pressure gas is then sent to the condenser indoors, where it releases the absorbed heat into the living space, warming the indoor environment. This cycle efficiently transfers heat against the natural flow from warm to cold, making heat pumps effective for heating purposes.