In the Phoenix area of Arizona (Maricop County), we have a serious problem with the lack (or practically NILL) mechanical, electrical, and safety code enforcement. The HVAC industry is full of undertrained installers and technicians and just outright HACKS! The HVAC contractors easily hire installers and technicians and send them out to install and service the equipment with no one to ensure they are properly trained or certified to do the job properly.

When I was an installer and technician in another area I was used to my employer pulling the required permits and having inspections. Each job had a county inspector go over the work and require us to correct any problems.

When I moved to Phoenix I was stunned with what I was seeing. This area is a massive HACKFEST and there is practically no regulation as to how any of these HVAC companies operate.
The customer himself is the only person to look over the completed job. And at that point it's the contractor's word over the customer's.

If we only could get this area to enforce these HVAC contractors to pull a permit and have inspections, we could stop 90% of this crap.

These improper installs create problems with the performance of the equipment (actual efficiency verus the advertised efficiency) as well as proper and safe access for the technician and safety for the end user.