What is the typical sequence of steps in a gas defrost process?

The typical sequence in a gas defrost process involves a systematic approach to effectively remove the frost accumulation from evaporator coils while ensuring minimal disruption to the refrigeration cycle. The correct sequence begins with the system operating in refrigeration mode, maintaining the cooling process to stabilize the system before beginning defrost.

A soft start is then employed to gradually increase the temperature, preventing thermal shock to the coils. This gradual approach ensures the systematic melting of ice or frost, which is essential for efficient heat transfer. Following the soft start, the system enters the defrost stage where heated gas is circulated to facilitate the melting process effectively.

After the defrost phase, a soft stop is implemented which allows for controlled cooling down and transition back to refrigeration. Finally, the system re-enters its regular re-freeze mode to return to optimal operational conditions. This sequence mitigates efficiency losses and ensures a seamless transition between defrosting and normal operation.

The other options do not present an accurate flow of the defrost process, as they either introduce incorrect modes such as fast starts or different operational phases that do not align with the commonly accepted practices in gas defrost procedures.