What can excessive refrigerant in a system lead to?

When a system is overcharged with refrigerant, it can lead to significant issues, one of which is compressor damage. The compressor is designed to handle a specific volume and pressure of refrigerant to maintain optimal operation. When there is too much refrigerant, the system can experience increased pressures that exceed those for which the compressor is rated. This excess pressure can cause overheating, increased wear and tear, and ultimately lead to compressor failure.

In contrast, the other options imply benefits that are not realized in an overcharged system. Increased efficiency might suggest a better operation under normal conditions, but too much refrigerant will strain the system, leading to inefficiency instead. Similarly, better cooling performance could be expected with a properly charged system, but overcharging can disrupt the balance and diminish the system's ability to cool effectively. Lastly, lower operating costs could be a result of proper system management, but excessive refrigerant typically leads to increased costs due to potential repair needs and inefficiencies. Thus, excessive refrigerant primarily poses a risk to the compressor and the system's overall functionality.