You can visually inspect the HVAC system on your own
It’s imperative that the ducts are fully cleaned especially since that’s what your facility is paying for, and also because any leftover dirt accumulation shrinks the HVAC passageway, potentially lowering efficiency and raising your energy bills.
Post Air Duct Cleaning Inspection.

Cleanness Verification
Post air duct cleaning verification is important, especially if you hired a lower-priced company.
50%
Filter Wrong Direction
Air filters are found to be in the wrong direction half the time.
70%
Blower Dirty
During an air duct cleaning the blower fan is usually dirty 70% of the time.
50%
AC Coil Dirty
Common during an air duct cleaning. The coil is dirty 50% of the time.