hydronic furnace

[Just_Steve]

Just hire an AC tech to come do the hookup of your AC lines. Unless you have everything needed (high-quality 2-stage vacuum pump with fresh oil, vac gauge/manifold good down to 400-500 microns, dry nitrogen and equipment to slowly flow it behind your brazing work, proper solder for this--don't even think of using plumbing solder), it is cheaper to get someone to come do it, and it is the law. Also, the receipt from the certified tech saying he/she did the hookup and checkout is typically what is needed to get the warranty on the condenser and evap coil. It cost me just $300 to get this work done, and was well worth it.
With AC, the qualiity of the installation is key to long unit life. I agree with those who say it is a much more significant factor than the brand of equipment chosen.

I would do any brazing with silver solder, definitely not plumbing solder. Most units come pre-charged and unless you are running a longer then a 15 ft line set shouldn't need to add much if any refrigerant.

 

[where I come From]

We utilize a Sanden CO2 heat pump air to water heat exchanger with a SS storage tank. But electricity is extremely cheap here in the NW. Works down into the negative temps but its output may not work depending on your load requirements. Our temps are about 55 day or night summer winter (I'm exaggerating a little) all year long. That and our home is extremely well insulated and sealed tight utilizing an HRV.