New to the forum just had a couple of questions. After having two hvac companies come out and consulting a friend of mine that does hvac work full time we need to replace our compressor. First our unit is only 10 yrs old and is using R22 freon. I have multiple quotes to 1) replace just the compressor with a dry unit, 2) to replace the just ac unit with a none R22 freon unit and, 3) to replace the ac unit as well as the furnace. My question is which of the three is the best option for longevity. I want to get the most years out of either of the options above.