OT-DIY ductless air conditioner install?

My solution to this problem was to find a suitable place on the outside wall and frame an opening for a small window air conditioner. It kept a bedroom cool and comfortable. I cut a small inspection hole first inside the room to make sure there were not electrical or plumbing items in the wall.

My local rental yard does not rent vacuum pumps. Too many were damaged by inept users.

I did it about 6 months ago for a friend. Purchased a vacuum pump and oil. Some pumps come with a gage, I had to add one which I had on hand. I also had to make an adaptor to fit the vacuum port on the outdoor unit. If you need one you can buy it, but I was able to modify a fitting off an old set of refrigerant gages. A pro would probably pressure check the lines. I made the flares very carefully and took a chance. So far so good. My friend couldn't seem to find a local pro for a reasonable price, otherwise that would be the way to go. It shouldn't cost much if you do everything but the final bit.

I agree. I had a unit installed a couple of years ago by a pro, and while I could have done the physical installation myself, I lack the tools and kno w-how to make the connections. I do know you can buy pre-made hoses for som e brands, but you'd still have to vacuum them out before charging.

All-in-all, the guy I used did a very good job and didn't charge much for h is labor, and I'm satisfied. If I were in your shoes, I'd first ask a local supply company who they would recommend to do the hook up for you. If you can work out a deal, go for it. Otherwise, if you can get the correct equip ment, this aint exactly rocket science.

BTW, I LOVE this machine. The house is more comfortable than I could ever g et it with window units, and even though I bought it for cooling, It worked great for heat last winter.

How did you obtain the needed refrigerant? I thought it took some sort of license.

Thanks for reading,

bob prohaska

Probably R-143a , which is unrestricted . You can buy it OTC at Walmart ...

These mini-split units tend to come with the outdoor unit precharged with the correct amount of refrigerant for the system. The indoor unit is empty as are the lines. The lines on the one I did were already flared at each end, but were too long. I only had to shorten them and flare one end. Once the lines are connected, they're open to the indoor unit, and isolated from the outdoor unit. You connect a pump to a port on one line, vacuum out the lines and indoor unit, then open the isolation valves. You're good to go unless there's a leak.

That was the case with my unit. Also the tech purged the lines with nitrogen.

I thought about using the argon bottle from my mommy's basement to pressure test the lines. But that should be done with a couple hundred psi, and none of mommy's regulators on tanks or in her junk box could do that. :)

It looks like the best solution is to mount the unit myself and then hire someone qualified to do the fussy bits. I'll have to see if anyone local will do this. Thanks, Eric

You've got the picture. My friend removed an in-wall AC unit, filled the opening, drywalled the inside and added matching siding outside, drilled for power and lines, fished power, mounted both units, insulated the lines and covered them with the supplied eaves trough-type stuff, and probably many more things I've forgotten. I ordered the pump, spent an hour prepping, and another hour gabbing while pumping. The bulk of the work is definitely the usual handyman stuff.

So, no added refrigerant required....very neat. Just for clarity, what refrigerant is used?

Many thanks!

bob prohaska