You should definitely be pricing with just heat pump. I live in NC which probably is a bit colder in the winter. We get down to the teens but only 15 nights a year maybe. Our winter average low is about 30. Under 10 degrees is definitely a news story. I have 5000 sq ft. I'm looking at my NG bill of $30. I have dual fuel and seer 16 heat pumps. Last winter was very cold and I spent about $700 with $200 being gas. This winter is going to be $120 in gas. My electric rates are similar to yours without the first 1000 discount. What is my point? Your gas usage will likely be $100 a year. Even if that were replaced with all heating strips, you'd be saving $200 a year or so. Since it would probable be 80% heat pump still, the dual fuel is only saving you $40 a year. So a $2500 furnace to save $40 a year seems a little crazy (on dollars alone). Turns out for me, it is probably worth it but only marginally so. I have a 90% (which you should be able to do as mine is basement with horizontal PVC exhaust). It probably saves $60-$70 on an average year. Probably cost $2000 (new house - I can't remember). What is that a 30 year payback (or never if you count interest or NG rates increase)? You do get some flexibility and you can setback at will with dual fuel. That is worth something.

beth answers going down your list.... 1.length of life can vary depending on use, environment, yearly PMs, and quality of original install I personally believe 15 yrs min is a good target for good equipment and believe me there are some real junk HVAC on the market 2.you can not compare today's HPs against those 10 yrs and older. as different as night and day especially in the area of supply temp. Supply temp on a properly charged HP should easily be in low 90s depending on outside temperature. one reason I put in a dual fuel system was because while I liked the idea of operating savings of electric vs nat gas, I was somewhat skeptical of the acceptibility by myself and family as far as comfort. No problem. it is fine. In fact, I wish I had gone with an air handler rather than backup var speed furnace. This past season I used about 60 therms of nat gas for heating as the heat pump did the primary heating. 3.I really think you are confused on question 3. Temperature is temperature regardless of the speed it is delivered. On today's high eff furnaces that are two stg (newest mdls can have three stgs) models with var speed blowers, the heat that is delivered is what I call soft, quiet, gentile heat as opposed to the conventional furnaces that deliver very hot noisy heat. The temperature from the high eff var speed condensing furnaces while higher than today's high eff heat pumps is lower than the hot blast of non condensing furnaces. You may get some debate on this subject but based on my measurements that statement is correct. 4.There is no such thing as a dual fuel heat pump. A heat pump with backup furnace(as opposed to an air handler with heat strip backup) is called a dual fuel or hybrid application. The operating savings depends on the price of electricity and price of nat gas as well as the efficiency of equipment for a high eff heat pump and nat gas furnace. A heat pump provides AC just the same as an AC condenser. I believe I have given you the fuel comparison calculator in your previous thread which offers an accurate indication of possible savings. I really believe you are overthinking your situation. These are the minimum specs I would use for HP selection. 15 SEER, 12 EER, 9 HSPF full BTUs in both heating and cooling mode matching var speed air handler or var speed furnace scroll compressor preferred electronic demand defrost thermostat that controls blower speed like the HW VisionPro IAQ IMO

He was going by the size of the existing furnace. He did say he thought it was way oversized, said didn't really need that big especially with a variable speed blower. I specifically asked him if it had demand defrost and he said yes, and explained it to me again. I did not ask if it was electronic, though. Are some of them not?

nesmia it would be difficult to find a properly sized furnace for such a small living space footprint. much easier to correctly size with a HP but dealer would need to check your electric service for breaker circuit capacity to handle backup/emergency heat strip. You need to analyze your electric and nat gas rates. see attached link for fuel comparison calculator. IMO Here is a link that might be useful: Fuel Comparison Calculator