Both are nice systems. For option 1, I would see about dropping down to the 25HCC524 heat pump. It is a Performance series unit (still quiet and efficient) and has many of the same features of the Infinity unit, but makes more sense to chose if you have do not go with the Infinity air handler and Infinity thermostat (option 2). With either option, I would select a variable speed air handler (option 2 has it). For option 1 it would be FV4BNF002 or FV4BNF003. Ask your dealer about this. Benefits are as follows. Variable speed motor ensures a constant airflow is achieved across the cooling coil, for greater efficiency and protection of equipment, up to a higher degree of external static pressure (airflow resistance due to duct design) compared to conventional blowers. Many ductwork systems run higher static (> 0.5") pressures at which standard blowers cannot maintain full airflow. Add to that a dirty filter, and pressure drop increases further. Variable speed blowers aren't a fix to poor ductwork but certainly makes sense in my opinion. Also, if you have them install the Carrier "thermidistat" model TP-PRH, the blower can be told to slow down upon a call to dehumidify. This helps in the summer.

The Infinity is definitely the nicer system due to the higher level of control it gives you over your indoor comfort. The Infinity will certainly be more efficient. For a 2 ton, second-story system, it may be harder to justify return on investment but you have to weigh the comfort advantages as well. Most 2-stage systems should be sold on their comfort advantages mostly.

Agree with Ryan. No need to go Infinity. Drop down to the Performance or Comfort Series 15 SEER and pair with the FV series var speed air handler. You would want the Edge thermostat that has dehumidify on demand feature. Also I would recommend the 9 KW prewired staged heat strip that has 3 KW increments. What are you doing about filtering your return air?

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IMO

I would want the Comfort 15 or Performance 15 paired with FV4CN(B,F)003 air handler. Gives you 15 SEER, 12.5-13 EER, and 9 HSPF efficiency with full BTUs in cooling and heating. All excellent numbers.

IMO

Thanks Ryan and Tiguerdunes.

To answer your question I am installing a "Honeywell Media Cabinet 4" Annual Filter that is included in the prices above.