When must an air conditioning system be evacuated?

An air conditioning system must be evacuated when it has been opened to the atmosphere. This process is essential to remove any moisture and air from the system, as the presence of these elements can cause serious damage over time. Moisture can lead to the formation of acids, rust, and ice, which can compromise system performance and longevity. Additionally, air can introduce contaminants that disrupt the refrigeration cycle.

Evacuating the system after it has been opened ensures that only the refrigerant remains, allowing the system to operate efficiently and effectively once it is reassembled and recharged. This is a critical step in maintaining the health of the system and ensuring optimal performance.