What role does a capacitor play in an HVAC system?

A capacitor is an essential component in an HVAC system, primarily serving to provide the necessary electrical energy to start and run motors. In many HVAC applications, particularly in compressors and blower motors, capacitors are used to create a phase shift in the electrical current. This phase shift is crucial for achieving the torque needed to start motor operations, enabling efficient energy transfer.

Once the motor reaches a certain speed, the capacitor continues to support the motor by maintaining the appropriate voltage and current to keep it running efficiently. This function is critical not only for the performance of the HVAC system but also for energy efficiency. By ensuring that motors can start quickly and operate smoothly, capacitors help prevent potential motor damage and prolong system lifespan. The other options present alternative functions that are not applicable to capacitors, focusing instead on air filtering, refrigerant pressure regulation, and temperature control, which are managed by different components within the HVAC system.