but a very very very very common cause is nominally low on refrigerant.
when a unit is nominally low on refrigerant, it passes through a window where it actually gets colder. (that’s counter intuitive) But as it leaks a bit more it will stop freezing up. But it will stop cooling also.
a tell tale sign of a unit that might be nominally low on refrigerant is it freezing up. That’s certainly not the only reason, but it’s a common one.
my god is that a pet peeve. there is a ton of silly over-engineering. I often think, “I’ll be damned. There is an engineer somewhere who thinks, “This will be neat!””
Both high fan and high fan will turn the fan on high. the only difference is high cool brings the cooling/ compressor into play/
if you’re trying to cool in low indoor ambient condition, high fan speed may harvest more btus due to lots of air.
I don’t understand why the OP doesn’t just open a window, or if there’s no other window in the room, take the the A/C out of the window and open it. You don’t need an A/C to cool air that’s already cool.
We have a window AC unit in our bedroom that is exactly the same, cools better when it’s hot out. The instructions say not to turn it on when it is cold out. We have, of course, but it doesn’t cool. In fact the other day we had it on and it was down to 60 in our room. About an hour later when I went back in to go to bed it was 64. As it got colder pretty quickly outside the AC could no longer cool, just like yours.
As to why we don’t just open a window ourselves we like the sound of the AC over the sound of the fairly busy street corner we live on. But you’re right, your A/C isn’t going to cool air that’s already cool and that has no moisture to pull out of the air.
In the past we had one of those portable AC units and it worked all year sitting on the bedroom floor. It was pretty good but it took up space and we were always having to fight with the line for the excess moisture that it pulled out. Many times it would quit in the middle of the night because something was wrong with that line so it defaulted to filling the internal cup and once it hit the point where it was full the thing would shut off to protect it from overflowing. We like our window unit better but in the winter we do sleep in somewhat warmer temps since it doesn’t really work. We use the fan function.
A white noise machine would use vastly less power than an AC that’s not actually doing anything but making noise.
The white noise machine would really have to be super loud to combat the very loud cars that go down the street if there were no windows closed to block said noise. I actually have one. The AC that makes noise with windows closed seems to do better on fan than the white noise machine with windows open.