Air Conditioning - replacing the condenser and Acoil myself?

Except for the final sweating of the lines, I'm drooling over the idea of replacing the outdoor unit and Acoil myself. I'm not sure if I need to replace the near 20 year old copper line set, but should I? Anyway, it seems like a simple job. Am I missing something? Can he just pump down the lines and Acoil and then open up the new unit?
Finally, would I offend the tech by questioning him if he's going to use nitrogen/type of solder etc or just assume he gonna do it right?

If he is EPA he should do it right also have him check and see if you have the right size lines there for the new AC unit?

ED :D

mitchella,

I too would drool if I could do a job for myself at half what it would cost a legitimate business to do for you.
And yes, you would offend a tradesman if you were able to find one willing to sell you an hour or two of labor in instead of the whole job and then questioned his work.

Speaking for myself I wouldn't waste my time when only charging a couple of hours and then opening myself up to having to deal with the after installation service.
Even if you swear up and down to not hold the installer liable for equipment failure, the place you buy it is going to blame the installer, guaranteed.
Believe me, I know.
Been there, done that and NEVER again.