In the hot gas defrost process, what type of gas is piped through the evaporator?

In the hot gas defrost process, high-pressure gas is piped through the evaporator to effectively defrost the coil. This method involves redirecting hot, high-pressure refrigerant coming from the compressor into the evaporator, where it replaces the cold refrigerant that is typically present. The high-temperature and pressure of the gas enable it to transfer heat into the evaporator coil, raising the temperature of the coil and melting any accumulated frost or ice.

Utilizing high-pressure gas in this way ensures that the defrosting process is efficient, minimizing downtime and maintaining the operational effectiveness of the refrigeration system. This method is common in industrial ammonia refrigeration systems, where managing frost build-up is essential for proper heat exchange and energy efficiency.