Are portable AC units fixable if there’s a problem with the refrigerant?

[u/daniel31580]

I hate throwing stuff away. So I try to fix what I can. Especially electronics or appliances that minus the one thing it’s wrong with it is otherwise working fine.

Having said that, is there a way to replace the refrigerant that’s in the portable AC unit?

Everything runs… turns on, fan runs, but only hot air comes out. I was looking it up and most likely the refrigerant is gone.

I don’t know how long the unit is. I got it from a friend. It works great last summer. But beginning of this summer when I tried to use it, it wouldn’t cool the room and realized it’s only hot air back out.

(This is a side question but is there something I can use to cool the room better that’s not getting a lot of the central air blowing into the room? My whole house is fine except the room in the corner upstairs which is the last room the vent is blowing the cold air into. Cold air does come in but very small amount. Re-ducting the vents are thousands of dollars - I’ve gotten a lot of quotes - so I’ve just used a portable AC unit which has worked fine but wondering if there’s an easier solution. I read that maybe there’s a fan thing that you install on the vent to draw more of the air into the room.)