I recharged the ancient coleman mach roof top AC unit on my camper with regular old R134 refrigerant you can buy at any auto parts store or Wal mart. So far it is still working. This unit was originally designed for R22 refrigerant.
There are plenty of videos of people recharging camper sealed AC units.
There are a few videos of people recharging a window unit for a house with R134.
However recharging a sealed AC unit on a camper with common cheap R134 automotive refrigerant is a highly controversial topic on google and youtube.
If you google this topic you will find alot of armchair HVAC technicians chiming in. I dont know why you would say it wont work if you never tried it. These people will cite all sorts of data and specs they googled. They make up stuff to sound smart online to impress random people on the internet I guess.
The "experts" say it cant be done.......
I believe I have put the naysayers to rest with this video.
I understand this is not a repair a professional HVAC technician would perform and warranty. Im sure this would void the warranty if you tried it on a new unit. Again mine is 22 years old.
So before throwing your old ac unit in the trash maybe give this a try.
You will need a bullet piercing valve with R134 adapter. They can be purchased on ebay or amazon. You will need to install the valve on the suction side of your AC unit. Plenty of youtube videos on how to do this.
The R134 can I used was a supertech 18oz can with gauge from walmart. Check the refrigerant capacity on your unit. According to google my unit is a 17oz capacity. Most will have a tag on the side of the unit when you remove the cover but mine was sun faded.
With the AC unit running on an 80 F degree day in the sun and my entire 18oz can empty in the unit my gauge was running 30 - 40 psi. The air comming out of my vent was 50 F to 60 F degrees.
I added automotive R134 AC compressor oil to my system... I dont know if thats neccessary, better or worse. I dont know how much should be in there. But I added some oil and so far so good. I figure any oil is better than no oil in the compressor.
If you want to research this topic look up videos on recharging home window units and other portable AC units.
Follow same instructions to recharge a R22 home window unit with R134. Its the same thing.
This channel is very helpful.
/ @jodbronson
If you ever recharged a cars AC you can do this. Its very easy. Honestly the instructions on the can is the same way I did it.
After the can is attached to the valve the unit must be turned on to suck the contents of the can inside. You must turn can upside down and right side up to get all the liquid and gas refrigerant out of the can.
When you are finished take a spray bottle with soapy water and spray around your new valve and the rest of the parts on the AC unit to check for leaks. If you see bubbles you know you have a leak that will need to be repaired.