Ross A dual fuel system can be a very effective strategy for heating one's home. Here are a few things that you should consider. 1. a complete understanding of nat gas rates and electric rates 2. your area's winter climate 3. your home's insulation qualities 4.a look into the future as far as whether electric rates are expected to be more stable than gas rates. In general, I have found that an electric rate of less than $0.11/KWh can make a high eff heat pump very compelling. I am attaching a fuel comparison calculator. Keep in mind that a heat pump performs double duty both in heating and cooling so its life may be marginally less on a dual fuel system depending on a good maintenance program. Today's heat pumps are much better as far as comfort than those 10 yrs+ ago. Good luck with your project and decision. IMO Here is a link that might be useful: Fuel Comparison Calculator

From a salesperson who said were dropping Ammana (and then forgot and included it in proposal!). Ammana significantly cheapened product since acquired by Goodman. As example, No longer have low pressure switch on certain model compressors! If low coolant, compressor burns out without shutting off. May want to check on model you are buying. On other products, wary of brand acquired. Buyer can take advantage of reputation while cheapening product if no long term commitment to new brand. Examples: GE small Appliances, Maytag appliances Only concrete thing here is low side pressure switch. If not on your model, would be crazy to buy.

I have a few comments I'll make on all four systems, but the ultimate decision will be yours. First off, I am assuming all four contractors properly sized your house's heating/cooling system based on a load calculation, or at least isn't oversizing anything. It is good to see that the sizing is in the same range across the board, with the hope it is correct. 1. Very nice equipment. Probably want to get the model number on the a/c unit as well to have it in writing. Ruud has high and low end equipment models, just like any other brand. 2. Nice system, comparable to the Ruud with the 2-stage advantage on the a/c side of things. PROBLEM: That's not the thermostat you want. That particular model only controls one stage of heat as far as I know, and you want one that can control both stages of the furnace's heat. Don't let them configure that nice furnace to just run off a timer. The Honeywell 8000 quoted in the others is a much better option. 3. The Infinity system, as I'm sure you've read, has its bonuses as far as indoor comfort control goes. However, the price justification is up to you. You can and will achieve similar results with either other system set up properly. If they use the old lineset, fine, but they should flush it out well. The 24ANA748 does not have the scroll compressor, which I personally prefer. It has the reciprocating compressor which stops in between stage changes. 4. No additional comments other than making sure the lineset is flushed out before reuse. Also, the HC-10 is a Lennox part number, not that it makes a huge difference for the air cleaner.

Demand for replacement furnaces is high right now, hence prices are high. If you can, always replace HVAC on the "shoulder" season (spring or fall) to get the best prices. Rebates and tax credits are a bit of a con as installers invariably jack up their prices by the amount of the rebate!