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

Sorry, I thought by matching we were talking about the refrigerate R-22 verses R-410a in the coils The coils will be First Co. Evaporation coils matching the existing air handlers I have. Apparently there is no AHRI reference number because First Co has not done any of the necessary testing. The dealer had told me this and that the system would not qualify for the tax credit. The third floor does not heat well with the present arrangement. All of the dealers have told me not to expected much cooling on the third floor. I did not question him as to what the "better options" might be.

A properly sized unit should be able to maintain reasonable humidity levels (though maybe not at 78 degrees without a dehumidification mode). The dual-stage unit will help control humidity. The only way of extra dehumidification with the XL16i that I know of is with the TCONT803/Honeywell TH8321 thermostat, which will overcool to control humidity. Ask your contractor why he proposed the VisionPRO IAQ when the BK terminal is already in use by the XL16i, thus not allowing the dehumidification feature of the VisionPRO IAQ (which is great as it actually slows down the blower). If you want an alternative that can make use of the VisionPRO IAQ, I'd go with the XL15i. It's a single-stage unit, but sized properly it should control humidity fine with the added advantage of the VisionPRO IAQ. Here are possible setups (ask your contractor what size he would recommend--I would NOT go with a 3 ton for your size home). Now, there are different air handlers that can go with these units, but the 4TEE3F39 air handler is tall due to the Vortica blower. The 4TWX5024A1000A (2-ton XL15i) with the 4TEE3F31B1000A yields 13.00 EER, 15.25 SEER and 8.60 HSPF. The 4TWX5024A1000A (2-ton XL15i) with the 4TEE3F39A1000A yields 13.00 EER, 16.00 SEER, and 9.00 HSPF. The 4TWX5018A1000A (1.5-ton XL15i) with the 4TEE3F31B1000A (only rated match with the 1.5-ton outdoor unit) yields 13.00 EER, 15.00 HSPF, and 8.50 HSPF. Feel free to print out my responses if it will be easier for you to go over these possible issues with your contractor. Good luck.

Maybe. Do you know if your current unit is correctly sized? Only way to be sure is to do a Manual J on your existing home, and with the addition included. Your existing system might be the wrong size for your existing home anyway. Do the calculations both ways and see what you'll need with the addition. It may also turn out that you can't do the ductwork easily to tie the new addition in to your existing system - a small separate system might work better. That's usually recommended for larger additions.. percentage-wise your addition is significant but it's not that big. If it's not practical to tie in to the existing ductwork you're probably looking at putting a mini-split in for the new bed/bath.