What happens to the evaporator when the refrigerant flow is restricted?

When the flow of refrigerant to the evaporator is restricted, the evaporator can indeed freeze up. The evaporator is designed to absorb heat from the environment, and it does this by having refrigerant flow through its coils, which evaporates and absorbs heat in the process.

When the flow of refrigerant is restricted, there is not enough refrigerant entering the evaporator to absorb the heat effectively. As a result, the temperature of the evaporator drops, and moisture in the air can condense on the evaporator coils. If the temperature continues to fall, this condensed moisture will freeze, leading to frost or ice accumulation on the coils. This can significantly impair the system's ability to absorb heat and, ultimately, its overall efficiency and function, possibly leading to a complete shutdown of the system in extreme cases.

Understanding the functioning and potential issues of the evaporator is crucial for HVAC technicians. When troubleshooting, technicians must pay attention to refrigerant flow, as blockages or restrictions can lead to frost buildup, impacting performance and causing additional problems within the HVAC system.