[peterk]

What should be the typical temperature difference between the intake and "exhaust" of a split system AC? How much does it depend on the intake temperature? I'm guessing that if the inlet is 40F vs 80F, delta T will be lower.

 

[beenthere]

Are you talking heating or cooling.

 

[biggles]

18F split return/supply on the air handler,and 10F on the condenser in/and blowing up and out if the charge is right.

 

[dac122]

The proper terms are return (intake) and supply (exhaust) across which you measure delta T. And as been has suggested the numbers are different whether in heating or cooling mode.

 

[peterk]

I'm talking about cooling.

I recently bought my first home and the HVAC system is very very old. With a 65F return the delta T is only 9 degrees. I'm trying to decide weather to get it serviced and make it last however long it will last, or bite the bullet and get a sweet 16 SEER system and that fat government rebate.

 

[beenthere]

9° is not much.
So it has a problem of some sort.

Weather its a diry coil, or low on charge or some other problem, can't say.

Depending on your location. You may be better off getting a new system. And upgrading to a heat pump.
The price difference is covered by the rebate. Plus you save some money on your heating bill every year then also.