athens....IMO....something isn't right some where. With your house still under construction with the doors and windows opened so often, that just doesn't add up especially with that much sf! I have a 14 SEER(one unit) and a much smaller house at 1600sf and mine runs more than that. How much is your kwh? You're in Athens and I'm beside Charlotte, so our winters are basically the same.

Cas How old is downstairs system? I see no urgency on replacing upstairs system especially since it serves a living area that is not used often. If you haven't done this already, you should a good PM/checkup performed on the upstairs system. I find the Rheem quote on the high side. I don't recommend going up in size unless ductwork has been thoroughly checked especially on size both supply and return to see if it can handle the additional CFMs. Obviously correct sizing is important. If you are unsure, then request a load calculation or even perform it yourself for a nominal fee online. there are three equally important components-quality HVAC, the install by dealer, and probably the most overlooked and disregarded is the ductwork system. these are my minimum specs for a new HP system. both outside and inside units should be replaced to have a properly matched system. 15 SEER, 12.5+ EER, 9 HSPF best matching VS air handler full BTUs in both cooling and heating for your rated size R-410a refrigerant(same as Puron) scroll compressor preferred electronic demand defrost preferred thermostat with "dehumidify on demand" feature staged backup heat strips new and correctly sized refrigerant line set you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc. any hot/cold spot issues in your home should be addressed. I would only use authorized dealers for the various brands that provide quotes. see mfg websites. I would look at Trane/AmStd,Rheem/Rudd,Carrier/Bryant. Depending on your location, I would not purchase a new HP system that did not have electronic demand defrost. Carrier does not. IMO

"Bad" power factor does NOT increase the REAL actual power consumed, "REAL" or actual power is measured in kW, that's all you use and that's what you're charged for. If device(CFL) uses 80% of the power going into it, the power factor is 80%. Power factor is the Real Power divided by the Apparent Power. For example, 98 kW (Real Power) ÷ 100 kVA (Apparent Power) = 98%. Again, residential customers are charged only for the REAL Power actually used, not the Apparent Power sent, That's not our problem, it is for the utility, believe me if it was a significant amount we would be billed a fee for power factor. Factories are billed for power factor,power factor does require the utility to compensate a little bit, it's at a far, far lower level than would be the case if they had to make up the total difference between the actual power factor and a power factor of 1.We can and do ignore the power factor issues in residential, there would be no way to diagnose anything if no rules applied or reality unable to be qualified. To prove this point, I set up an experiment with CFLs vs. incandescent lights (resistive loads with a power factor of 1.0), and measured watts and volt-amperes delivered by my inverter. Then I measured the amps from my power source, a bank of L-16 batteries, which are DC sources wise to the tricks of reactive power....The low power factor did not require the batteries (or the utility) to produce any extra energy.

I am reading all these posts with interest as I have now received my first electric bill for a FULL month with my new system. I put in a Carrier standard blower 13 SEER 2 1/2 ton heat pump/AC system with Puron. It replaced a 20-year-old Trane heat pump/AC. It is certainly not an awful electric bill but I was hoping to see a little bit of savings: Oct 07 with 31 days, I used 612 KwH, and avg. temp was 71. In Oct. 06, also 31 days, I used 703 kwh but the average temperature was much cooler: 64. Since I probably used some heat a year ago and I have been using AC this month , I figure these are probably pretty comparable months. My bill is: $88.42. For the year-ago period: $83.37. The price per kwh now is: 10.86 cents per kwh; a year ago, it was 11.03 cents (this was back when we were getting that "reduction" from the enormously high bills, as those of you in Md. will recall). I work from home and so tho I have a programmable thermostat, I never use that function, just adjust. I keep the house as 76 (75 if it is truly awful out) in the summer and in the winter, 72 (again, the truly bitter cold will get me to aim for 73 or 74). I turn the AC off at night most nights and just use a ceiling fan; it is often off during the day as well since I work in the (almost always cool) basement. Nothing else has changed "electrically" here; my hot water, refrigerator, and other power uses are unchanged, nothing is broken, etc. Obviously, I did not purchase "high efficiency" system but I assumed all NEW systems are more efficient and hopefully a little less expensive to run. I guess this was a wrong assumption.