charging unit

[fliks]

I would never charge a system with a dirty coil but have seen an a/c tech charge an orfice type system with 10 seer inside coil, 13 seer outside condenser,and a dirty coil.I guess you could weigh in the additional r-22 but can you be certain the condenser has what it claims to have? Also would this be the same considering the unmatched system? He is doing a superheat but I don't see how that can be done with a dirty coil. I'm always trying to learn and this is an excellent place to do just that.Thanks

[iraqveteran]

he did it wrong.

Probably didn't need any refrigerant. Clean the coils and the system woulda worked.

Now its overcharged and the customer has been a victim of the "gas and go"

[2old2rock]

Mis-matched units are tricky, but sometimes that's what you've got. If they're dirty, your chances of getting it right go way down. I make sure they're clean, good air flow, and charge them like a normal system, (SH/SC), but I don't always get perfect results.
Anyone else have more suggestions for getting a mis-match right? I'll take any ideas.

[I_bend_metal]

Better measure that airflow before you touch that charge also....clean everything then verify airflow...other wise it will never be right.

[catmanacman]

the dirty coil is probably the reason the other compressor failed