We live in Atlanta and recently replaced our main floor system with a 3 ton Trane XL15i AC, HE coil and XV95 Trane furnace. We'll be able to get a tax credit on the furnace for this system. We're very pleased with our system and grateful for the advice given on this forum for that install.

Now our upstairs coil is giving us trouble. We've had to add freon a couple of times this year (in May and last week). No telling how long it will last and it's still hot here. We've settled on using Trane equipment again, but we're not sure if we should replace the AC this year or wait until next year, providing the freon holds for another month.

If we're not concerned about getting the tax credit, I'm wondering if we'll get better pricing next year. Is there a "best time of year" to purchase Trane equipment? And, I wonder if contractor pricing will change once the tax credits go away.

My second question is technical. The AC we're considering is a 3.5 ton Trane XL15i. Our current 4 ton, single stage, 80% efficient Carrier furnace is 11 years old and running fine. Would it be ok for us to hold off on replacing the furnace, too, or would that somehow tax the new AC system? Would keeping our current Carrier furnace, negatively affect a new Trane AC warranty?

Thanks in advance for any feedback.