Your Ears: Your Best Diagnostic Tool
Don’t laugh. I often get that reaction when I tell people that the single best diagnostic tool that we possess in HVAC is our ears. But it is true!
Sound contains more information than can be fully understood, and that is doubly (or more) true when you are sufficiently familiar with what something “usually” or “should” sound like that you can make comparisons. Your brain is a far more sophisticated computer than anything made by man, and it is only limited by the quality of the input that it receives. Sound is a primary input, and from a mechanical standpoint the most important.
For a short discussion of how sound can be used to diagnose problems with such common HVAC issues as improper scroll compressor rotation; pump cavitation; failing bearings; sound problems due to duct rumble/ turbulent air flow; fan balance, fan belt tension and fan sheave condition; pneumatic controls air leaks; and worn compressor valves, take this link to my So Cal ASHRAE January newsletter Mike’s Monthly Maintenance article:
http://ashrae-socal.org/pdf/SolAir_January_2016%20Final_v60No5_rev_0.1.pdf