HVAC replacement advice

Time to update?
I've a York system: gas furnace (upflow), model #P2udd16n07601c that will be 17 yrs in May 2010. I believe it is a 92% efficient model (can anyone confirm AFUE%?) rated at 076 mbh. It is mated with a York AC coil m3uf044sa, and condenser h1da042s06a that I think is a 10 SEER and rated at 42K BTUs.

It seems to be running fine and the house is comfortable. I was thinking of replacing the system given the rebates available and the age of the unit (rather replace it on my schedule than on a cold winter night) but don't want to blow money needlessly. I ran a rough payback calculation and it was at least 11 years on the AC and greater than that on the heat (something over 20yrs with 92% efficiency).

My questions:
1. Knowing predicting the future is difficult, how likely is this going to need major repair given the age? Only the blower motor for the furnace and the run capacitor and contactor for the condenser (preemptive change) have been replaced.
2. I've looked at most of the major mfgs and wondering if 2-stage if the minimum to go with these days?
3. Favorite question: which mfg to pick from? I know you all say it depends on the installer and Manual J calc. Any suggestions as to which product attributes to decide upon? Example: hx materials (stainless or aluminized steel), ecm motor, 1-, 2-, or 3-stage furnace? variable speed blower? Single- or two-stage compressor for AC? AFUE: 92%, 93%, 95% etc? SEER for AC?


Thanks in advance for any suggestions.

 

No one has an opinion?

 

I wouldn't be in any big hurry to replace it. Any decent furnace should last at least 25 years.

The A/C might be worth replacing based simply on SEER. This is where the bug-a-boo comes in: In order to get a decent SEER rating (16+), you have to have a variable speed (ECM) blower motor which means replacing the furnace since I'm sure just a blower upgrade to your existing furnace would run $1000 or more.

Now that I've opened that can of worms: I prefer stainless to aluminized steel (just personal preference), probably 2 stage, & certainly an ECM. Brand? I care not. Installation, installation, installation.

 

Since you are into efficiency with paybacks - what about any programs for improving the house to make it more efficient? Here is a good example: I know someone who lived in a trailer that was about a 12 x 50, and whose gas bill was over $100 one January. For that same month, another person lived in a 14 x 60 - a larger trailer - yet their billwas $32 for that same month! They had the pitched, better insulated roof, real-type house windows rather than those leaky 3-awning windows(also refered to as Florida windows), and 2 x 6 walls.The other trailer was, well, a piece of junk - a pre-UBC (uniform building code/1976) home.

Have you ever thought about going for broke and going geothermal?Supposedly that can reduce your bill by up to 80%. Not COST 80%; Reduce it 80%.

 

Grady: Thanks for your suggestions; I assumed SS was a better HX material and variable speed ECM motor. Hopefully these motors are more reliable than earlier models? I understand they are a bit pricey to replace.
Ecman: House is about as efficient as it is going to get without spending mucho bucks on window replacements. Geothermal is great but unsure payback period would be worth it.