The answer is no-you will not need to replace your 4 ton 13 SEER AC R-22 condenser. You will need a replacement furnace that has a 4 ton rated blower. Since you have an Am Std condenser, I would recommend Am Std equivalent furnace XV80 80% eff 80 KBTU size. Include a true 2 stage thermostat. You can change out to new refrigerant when your outside condenser needs replacing. Also I recommend a whole house filter media cabinet if you don't already have one.

IMO

Thanks for the fast reply, do you happen to have a model number of that unit? Thanks for all your time on these boards, it is appreciated.

What size living area for upstairs?

I assume existing furnace is 80% eff. Where is it located?

Here are the model numbers. Not clear what difference is between the A and B model. AS dealer could clarify.

AUD2C080A9V4VA 4 41,600 64,000 80 40 21 28 166

AUD2C080B9V4VB 4 41,600 64,000 80 40 21 28 166

Excellent equipment and you could easily add the AS R410 condenser when existing comes to end of its life.

Because this furnace is 2 stage, it requires a true 2 stage thermostat. No substitute or you will always run on high stage heat whether needed or not.

Any questions, please advise.

IMO

I'm reviving this older thread as I just got some estimates to replace the above mentioned Quattro unit. The CE3AXA evaporator coils on this are clearly leaking so I'm probably going to act on this during the winter.

The outfit I'm working with (and completely trust and respect) are Trane dealers. What are your thoughts on these options:

1. AHRI certificate # 5868069

 Trane XR16 Condenser (4.0 TON) Model #: 4TTR6048B1000A

 Trane High Efficiency Coil 4.0 TON) Model #: 4TXFH054CC3

 Trane High Efficiency Furnace (XT80 4.0 TON) Model #: TUD1C080A9H4

 Honeywell Redlink Touchscreen Thermostat Model #: TH811OU1008

Cost: 6800

2. AHRI certificate # 5996438

 Trane XR17 Two Stage Condenser 4.0 TON Model #: 4TTR70481000A

 Trane High Efficiency Coil 5.0 TON Model #: 4TXCD063AC3

 Trane VARIABLE SPEED Furnace (XV80) (5.0 TON) Model #: TUD2C100A9V5

 Honeywell Redlink Touchscreen Thermostat Model #: TH811OU1008

Cost: 9200

3. Option 3 would be to just replace the furnace with an XV80 5 ton TUD2C100A9V5 and wait on the coil and condenser. Cost 2800

I'll be adding a few more return air lines and add media filter as well, but that is not included.