I am replacing a dual fuel system that is 18 years old...heat pump with LP gas backup. The home is also 18 years old with about 2650 sq. ft. of living space. I am in central Ohio.
I have narrowed it down to two options both of which include the Carrier Infinity 80% furnace (80,000 BTU). This unit has the variable speed fan and 2 stage burner. I've decided that since the furnace will only be used at the coldest temps it would not make economic sense to spend the extra money for a high efficiency furnace such as the Carrier Infinity 96. In a typical winter I use only about 250 gallons of gas and the 80% furnace should cut that considerably.
On the heat pump (3 Ton),I'm trying to decide between the Carrier Performance 13 and their Infinity 17. The SEER rating of these two units are 14.5 and 17.5 respectively, a significant difference but the HSPF ratings aren't that different at 9.4 vs 9.5.
Since I live in Copeland "territory" and am personally acquainted with several engineers and marketing people employed there, I've been barraged with the benefits of the scroll technology. Therein lies part of the rub.
The Performance 13 HP has a scroll compressor whereas the Infinity 17 has a Bristol 2 stage reciprocating unit.
So, I'm torn between the less efficient HP with the scroll or the higher efficiency 2 stage design with recip'g. compressor. The cost difference is about $900.
My questions are as follows:

1)Is my logic sound going with the 80% furnace?
2)Infinity 17 or Performance 13 HP?
3)For the Infinity 17 HP and Infinity 80 furnace combination does $xxxx installed seem like a a fair price. Two contractors were within $100 of each other at this price.

Lastly, my current system has an electrostatic air cleaner that still works although I now have a preference for the simplicity of a media filter (EZ Flex). I am thinking of leaving the existing electronic air filter in place but removing the metal mesh pre-filter to minimize the pressure drop across it. Then, I would add ahead of this the new media filter. My logic is that the electrostatic filter would remove smaller particulate that the media filter won't. When the electrostatic filter "gives up the ghost" I'll just remove the cells rely on the media filter only from then on. In other words, I'll just take advantage of whatever life might be left in the electrostatic filter. Am I nuts thinking this way? Will this approach comprimise the overall syatem in any way?
Thanks for your input!

[Edited by lusker on 04-22-2005 at 08:29 PM]