Tech A claims that evacuating an A/C system removes air and moisture, while Tech B states it removes dirt particles. Who is correct?

Evacuating an A/C system is a crucial process that primarily serves the purpose of removing non-condensables, such as air and moisture, from the system. When air enters the A/C system, it can lead to several issues, including reduced efficiency, corrosion of components, and potential system failure due to moisture leading to acid formation. Thus, the primary benefit of evacuation is indeed to create a vacuum that eliminates these undesirable elements, ensuring the system can function optimally.

While Tech B's claim about removing dirt particles does touch on a valid concern in A/C maintenance, it is not the primary focus of the evacuation process itself. Filtering out dirt and debris is typically handled through regular system maintenance and by using appropriate filters, not during evacuation.

Therefore, the assertion made by Tech A accurately reflects the key objectives of the evacuation process in an air conditioning system.