Carrier not cooling

[jamo1989]

Iv been working on a carrier apac ducted. The system is about 15 years old. The unit apparently used to cool the entire house quite well. It is a 17kw R-22 reverse cycle. And now it takes along time to cool the house just enough to be comfortable. I have cleaned the indoor and outdoor coils, changed the filter material in the filter, and it still hasn't helped. The refrigerant charge seems to be ok going by the gauges and sweat on the suction pipe. I have taken some temperature readings and was hoping if someone could tell me if there is something wrong or not.

Temp on the indoor 32 C
Temp off the indoor 22 - 23 C

Temp on the outdoor 30 C
Temp off the outdoor 45 C

Suction line pressure. 9 degrees C
Suction line temp 11.7 degrees C

I was a bit worried about the super heat, should it be a lot higher than 2.7 degrees?

[frank]

You have put the suction line PRESSURE as 9 degrees C ?

You need to attach service gauges to obtain a pressure reading

[rude]

May seem silly but no duct has blown off has it?

[jamo1989]

It was about 80 psi mate, and yeah I checked all the ducts!

[The Viking]

10 degrees delta T across the indoor coil at 30ºC ambient?

It is doing really well!

The big question isn't the performance of the units but rather why the indoor unit ON temp is 2º above ambient.

:cool:

[Magoo]

Hi Viking.
It is very likely the space return air temp will be higher than ambient. Ducted return air through ceiling space possibly un-insulated added fresh air make up and solar gain from whole structure.

Jamo,
I would suggest the compressor is tied and not doing the job after 15 years. A compressor change would be my recommendation. Check drawn motor amps If compressor really hot to touch discharge valves are warn. Recover refrigerant and swop out compressor for a new one and start again. The air split across condenser is too low for +30' C ambient, so you get high SST and low performance.