Which of the following is NOT a major component of an HVAC system?

The refrigerant is not a major component of an HVAC system in the same way that the evaporator, compressor, and condenser are. The evaporator, compressor, and condenser are the primary mechanical parts that are crucial for the functioning of the HVAC system. They work together to facilitate the cycle of heat exchange, which is essential for cooling and heating spaces.

The evaporator absorbs heat from the indoor air, the compressor circulates the refrigerant and raises its temperature and pressure, while the condenser releases the heat absorbed by the refrigerant to the outside. In contrast, the refrigerant serves as the medium through which heat is transferred but does not perform a mechanical function on its own within the system. Thus, while it is essential to the operation, it does not comprise a core structural component of the HVAC system.