Automotive Service Excellence (ASE) Air Conditioner Certification Practice Exam 2026 - Free ASE Air Conditioner Practice Questions and Study Guide

Using compressed air is an effective method for cleaning a clogged evaporator case drain because it can help dislodge debris or blockages without introducing moisture or chemicals that could potentially harm the system. Compressed air can blow out dirt and other obstructions that may be causing the clog, allowing for improved drainage and proper system function.

Warm soapy water, while it may seem like a practical solution for cleaning, can leave residues that could cause further clogs or mold growth if not thoroughly rinsed, which is typically not feasible in the drainage area. White vinegar is an effective cleaning agent for some applications, particularly for descalers, but it is less effective at clearing physical blockages compared to compressed air. Sodium bicarbonate solution could react with acids but is not as effective for physically clearing blockages in the drain. Instead, it’s better suited for deodorizing or mild cleaning tasks.

Overall, the use of compressed air is preferred in this scenario, as it provides a straightforward, effective way to address clogs without the risk of introducing unwanted substances or compounding the issue.