Got a call from fellow, whose central AC isn't keeping the house cool.
Rheem system, probably 20 years old. Two ton capacity. I didn't see any filter dryer along the line. Indoor coil might be captube, or orifice. I did have one of the covers off, but didn't see anything that looked like an orifice.
Didn't write down the pressures, but they were running maybe 65 and 250. Suction line room temp.
I cranked in a couple pounds of juice, and the temp of the suction line didn't change. Suction pressure went up, a bit, though.
Next day, not much more cooling. Went back and recovered the charge, and weigh it in. Line set about 50 feet, and still not cooling. The liquid line off the condensor is room temp. Outdoor temp about 85F. The chart he had that came with the unit says to charge to 243# on the liquid side, and it was close to that with a correct charge weight.
Anyhow, the distributer tubes from the orifice (or the captubes, if it's a captube coil) remain warm, and the house remains warm.
So, what's the diagnosis? And what's the treatment?