Jay-n-123 wrote:
I'm considering getting an extra portable AC on wheels for the bedroom
(which is upstairs) in case my 20 year old central AC were to
suddenly die. That way, I'd be able to get some sleep at night if I
weren't able to immediately have a new central AC installed or the
existing system couldn't be immediately repaired. Is this a good
idea or do you I am crazy to want to spend a few hundred dollars on
something to use as a backup for the bedroom in case the central AC
should fail?

Install a 5,000 BTU window unit. Turn off the house AC at night.

Your electrical bills will drop by almost half.

As for installation, we removed the glass from one pane and replaced it with
3/8" plywood, then cut a hole in the plywood to house the AC unit.