Art Adams Appliance Repair / Upstanding business practices.
Art Adams service person stated there was a leak in the evaporator coil based only on the frosted coil. It must be replaced, $757 total. The unit was still working, but not fully cooling any longer even at ther highest setting. My experience is that this is a sign of low freon charge level. I am an engineer and have successfully repaired and recharged whole house and automotive units in the past. At 10 yr old the the loss of some freon is not too unusual and I asked for a recharge instead of replacement of the coil. Even after talking to the supervisor the repairman would not do that claiming that the law required them not to repair a unit with a "known leak".
The only law I found want the Title IV of the Clean Air Act of 1990 requireing large refrigeration units (over 50 lb of freon) that lost more than 15% per yr to be repaired. This unit would not fall under that law for size and is also a very much slower "leak". It would have been much more "green" to simply top off the charge. Anyway, it was let them replace the coil and recharge it or go through the whole process again. While I figured the law did not exist they had me at a disadvantage. I would suggest a different repair service if you want to try to find a service with more upstanding business practices.