I bought a used minisplit air conditioner for the compressor, thinking it would chill water for the radiant cooling system. But I have decided after lots of experiments with radiant cooling to just install it as an air conditioner this year. It is only a 9000 btu cooler but mini splits have the ability to modulate cooling so 9000 can cool up to 12000 btu or one ton and can scale down to about 30% of capacity (about 2700 btu) if less cooling is needed.
It is a Frigidaire 115 volt unit and the electricians installed an outside electrical box for it last fall.
The minisplit is plumbed with two refrigerant lines and a drainage pipe as well as the electric cord that goes through the same hole in the wall between the inside and outside units.
Access to the area where the minisplit air conditioner lines have to exit the house will be restricted after the drywall is installed. So one extra item on the list of prep tasks was to drill the hole in the rear wall for a pipe to accept these lines.
Drilling the hole was more difficult that I imagined. I knew the electrician had difficulty drilling through the same wall so didn’t expect it to be easy. He only had to drill a 1″ hole and I have to drill a 2″ hole. Actually 2 1/8″ for the pipe. I have been drilling almost all day first from one side and then from the other, hoping the holes would line up. But they do not seem to be meeting and I’m out of drill bit length on both sides.
I read about drilling deep holes on the internet and found that there are drill bit extensions for hole saws so I bought the Milwaukee 12″ extension which worked great and I was able to line up the two holes.
I put a left over vacuum pipe in the hole and screwed it in on one side so it is stable. I just have to fill the surrounding area with foam spray and seal it up with membrane and tape again.