What is the minimum level to which a system can be evacuated if a leak is detected?

When a leak is detected in a refrigeration or air conditioning system, the purpose of evacuation is to remove moisture and any non-condensable gases that may have entered the system, while also reducing the pressure to prevent further leaks. The minimum level to which a system can be evacuated is atmospheric pressure.

Reducing the pressure to atmospheric levels allows for safe access to the system for repairs without risking further refrigerant loss or creating hazardous conditions. It creates an environment where technicians can effectively troubleshoot and fix the leaks. In most cases, going below atmospheric pressure can introduce new issues, such as drawing in more air or moisture, which can cause even more damage to the system.

Hence, achieving a state of atmospheric pressure is a critical and practical step in the process of maintaining and repairing refrigeration systems after a leak has been confirmed.