Learn Basic HVAC for better
I was having difficulty finding parts for my 49 year old central air unit, so, with great trepidation, decided to have it replaced.
I began the process by learning everything I could about central air unit. Wound up getting my own refrigeration license, but that's another story. I collected bids with specifications as identical as possible.
I talked with the most knowledgeable HVAC men I knew of in other states who would not be bidding on the project and decided to go with a Goodman system, Copeland scroll compressor, TXV, sight glass, better filter, etc. The bids varied considerably. I chose one from a reputable company that's been here for 50 years and with which I had dealt in the past.
I knew they had an excellent installation tech. The price was $3650. That included 10 year parts and labor warranty on everything, lifetime part on compressor, annual cleaning, etc. I watched the entire installation carefully and the quality from the duct modifications (all fabricated sheet metal ) to the brazing (all under N2), high pressure leak testing, over-night evacuation, etc., etc. were very good.
There are only a few manufacturers of components. Goodmans are assembled in TX, not made there. Everyone seems to be using Al evaporator coils now, for better or worse. What counts most is the quality of the installation. If you don't educate yourself, you are likely to become a victim. Check the BBB data, ask for references and call them, learn about HVAC.
The HVAC business is almost as corrupt as car dealerships (my opinion). The vast majority of the complaints I've read about here and elsewhere seem to me to be the result of inferior installations. No one is going to look out for your best interests except you. Educate yourself!!! READ!!
I will probably report again as the system (and the owner) age.