Which component primarily benefits from the usage of hard-start kits?

The component that primarily benefits from the usage of hard-start kits is the compressor. Hard-start kits are designed to provide an additional boost of power to help the compressor start up more quickly and efficiently. When a compressor first starts, it can draw a significant amount of current, often referred to as inrush current, which is much higher than its running current. This inrush can lead to difficulties in starting, especially in older systems or those with weak voltage supply.

By using a hard-start kit, which typically includes components like a potential relay and a start capacitor, the extra power enhances the starting torque of the compressor. This improvement helps mitigate potential issues such as overheating, stresses on the electrical system, and even the risk of compressor failure due to insufficient starting power. The result is an efficient startup process, reducing wear and tear on the compressor and extending the overall lifespan of the system.

The other components mentioned do not require the same assistance during the startup phase as the compressor does, making the hard-start kit specifically beneficial for compressors in heat pump systems.