On the other hand there are many more air duct cleaning companies that will properly clean the air system and air ducts and use commercial negative air duct cleaning vacuums with at least 2,000 CFMs of vacuum power and utilize proper agitating tools to move the contaminates within the duct work to be captured with HEPA filters and contained by the air duct cleaning vacuum equipment.
My heat pump unit was not working, though the handler and thermostat were fine. I did a little testing myself and determined that the low pressure switch was triggered, then called Waychoff's without having told them anything about what I did (sort of a test to see if they'd try to sell me something I didn't need). Eric showed up 30 minutes early to the appointment (a pleasant surprise), and immediately got to work. Within 10 minutes he told me I had no coolant which triggered the low pressure sensor which meant there was a leak. He inspected the handler inside and then told me he needed to do a nitrogen pressure test to find the leak. 10 minutes after that he showed me the hissing leak in the heat pump, proving that there was in fact a leak. He brazed/welded it shut, re-tested to confirm, then filled the unit with coolant. 60 minutes later I'm back in business and my heat pump is working great. I liked that Eric was 100% honest about the issue and how to fix, and didn't try to sell me anything I didn't need. He also worked with me on the coolant charges, since they tend to mark it up quite a bit. Overall a good experience - I'd use them again for sure. They're a little bit pricey, but for the quality, honesty, and knowledge it's worth paying.
Make sure that the company has the proper equipment and enough HEPA filtered vacuum power (2,000 CFMs or more), to properly clean your air ducts. Be weary of companies that use small vacuum units that have a small rotating brush on the end of a small vacuum hose with a typical airflow of 150 to 300 cfm or less. Proper air duct cleaning vacuums are negative air machines with 2,000 CFMs have 8 inch to 14 inch or larger, vacuum hoses to capture large quantities of dust and debris.
"This a very professional company that came the next day after being contacted late in the day prior. The two guys that came to the door that did the work were well dressed and very courteous. They cleaned my diver vent and it works perfectly. I have their literature and will be calling them when I m ready for duct cleaning. Nice equipment too! Thanks for the good work. Nice not to have scroungy guys showing up at the door. "