I am in the same room as the air conditioner, it's right behind me. It's blowing cold air. I'm on the second floor of an apartment building, the outside is brick and the roof is a fresh flat rubber roof. My apartment in particular sees 100% of the day's sunlight. It has been 90F and sunny for the last 2 days. The air conditioner kept it at 73F most of the day, but when the sun goes down it only gets hotter in here. You see, the bricks absorb the heat all day, then discharge it inward at night. It doesn't dissipate outward, only inward it seems. My outside walls are warm.
I'm sitting still, in basketball shorts and a tshirt with the sleeves cut off, and I am sweating.
We have a second portable air conditioner, but the compressor stopped running at the end of last summer. Now the fucker doesn't even power on. It's well out of warranty.
Fuck me, I'm getting desperate.
There is no reason for that...you should be making an igloo in there.
It sounds like you know your shit, so I hesitate to mention things like cleaning the filter or checking the coolant (depending on the unit you have, it might not even be an option). If it's blowing cool air at you, you might try hanging a blanket in the doorway at the far side of the room - it'll make a difference pretty quickly, but only in that room.
Other than that, I am not sure what to say. I'd trade with you right now - I just had to turn my space heater on. It's 58°F in here.