New to the forum here, looks great! I bought my condo a few years ago and there was a Rheem 9 Classic Heat Pump on the balcony when I moved in. It turns on and off fine, but the pressure of the air coming out seems very low and the air is not very cool. When I got my inspection, the inspector told me the delta temp between air coming out and air coming in was about 10-15 degrees too low when the AC was on. I replaced the filter when I moved in(inside the house) but I'm assuming this thing is OG so the unit itself has gotta be about 22 years old?

I live in SoCal so I don't use the heat much, but this summer has been insanely hot and still is insanely hot. Can't take it anymore, so I'm wondering if these type of units can be fixed with new freon or should I get a whole new unit? I really don't want a whole new unit and probably won't get one so any ideas about what may be wrong with my current one would be greatly appreciated.