It has been my experience that you should simply go through a professional for the most immense renovations.
Usually the people I was with and I have met somebody who knows somebody who can get you a wonderful deal.
There are plenty of local people ready to work, no question, however going the cheap route definitely could cost you immense time. An associate of mine got a local crew to do his roof, and they were cheap however not professionally insured at all, so when his roof turned out problematic, it was strenuous for him to deal with. He had to call a professional to fix it! The same is true with Heating and A/C work, so please don’t even let some uncertified yahoo poke around in your method only because he says he knows what he’s doing… Let me tell you something, nobody has an official position and also does Heating and A/C work on the side. This work pays wonderful cash, so clearly if you are certified and experienced with air conditioners and furnaces, then I think your official work would be doing that, you follow me? If they are a cheap freelancer who simply claims to have AC experience, they are really conning you; Even if they aren’t, I definitely still wouldn’t let them mess with your Heating and A/C equipment, just in case something seriously goes wrong. Use a certified, licensed Heating and A/C contractor or business, I mean… it will be cheaper than paying a yahoo, and then having to pay the real Heating and A/C contractor anyway to fix the issues caused by this idiot.