What happens during a runaway condition in a refrigeration system?

In a refrigeration system, a runaway condition typically occurs when there is an excessive buildup of heat or pressure that the system cannot effectively manage. In this scenario, the most relevant outcome is the formation of ice on the evaporator coil. This phenomenon happens because the evaporator is unable to absorb heat effectively, leading the moisture in the air to freeze on the coil's surface.

When the evaporator coil becomes too cold due to insufficient heat exchange, temperatures can drop below freezing, allowing ice to accumulate. This ice buildup restricts airflow and further reduces the system’s capacity to cool, leading to inefficiencies and potentially causing additional issues within the refrigeration system, such as compressor damage.

The other outcomes listed do not accurately describe what happens during a runaway condition. For example, a compressor cannot operate at higher efficiency under these circumstances, as its ability to function properly is compromised. Similarly, the system is not cooling effectively at all, and while refrigerant vaporization is part of the normal cycle, it does not occur completely or efficiently in a runaway scenario. Understanding this runaway situation is critical for diagnosing system performance issues and implementing proper maintenance.