High air off

Can anyone tell me if theyve experienced similar to this.
I had a split system that was supplying air at 20c. Obviously i felt this was a little high but when i checked the air on in the computer room it was around 29c. So my thermometer reading across t2-t1 was giving me 9c across the coil. Would that be working correctly with the supply decreasing in unison with the return or should i be getting a greater temp difference at those conditions?
Ive had similar circumstances with high returns but usually still experiencing lower air off readings.

Your dT would be dependant on the wet bulb temperature of the room (entering air). without the wet bulb (air humidity / enthalpy) information, the dT information really does not tell you much.

If you are troubleshooting a cap tube system, the manufacturer likely provides a psychrometric chart which references wet bulb temperature to determinae what the dT should be.

:)

I agree with herefishy but I would consider 9C across a split ac coil as doing it's job, don't worry about it.

If the temperature isn't coming down then sell them a second (backup) unit.

Dear reggie! System probably is not picked correctly up.
Check up thermal balance.
9C little bit less than it is necessary (I think norm 10-12C),
carry out standard service procedures.
Good luck!(Excuse for language).:cool:

To properly evaluate this system we would need a lot more information. Is this a TEV or cap tube system? Does it have any form of capacity control (unloaders, hot gas bypass, EPR, etc.)?

Then we would need the following temperatures:

Low side:

Evap air in temp
Evap air out temp
SST (saturated suction temp)
Suction line temp at coil outlet
Suction line temp at compressor inlet

High side:

Cond air in temp
Cond air out temp
SCT (saturated condensing temp)
Liquid line temp at condenser outlet
Liquid line temp at TEV inlet

We would also need to know the average space temperature (presumably the temperature at the thermostat).

There is no reason to assume a high humidity load in this type of application, although that is a possibility. I might rather suspect excessive fan speed, which would result in higher efficiency but poor humidity control, but this would involve a great many assumptions. Much better to gather the data and and make a more accurate determination.

This may seem like a lot of information to gather, but with it we can fine tune a system to run better than it ever has before, often exceeding factory specs. It takes a little longer to do it right.