Hi Beth, If you search this forum "geothermal heat pumps" or "Climatemaster" or "Tranquility 27" you should find my thoughts and warnings about the matter. After a year and a half with the new system I still like it, but there are some things to be aware of. (And it occurs to me I might have posted those things on the Renewable Energy for the Home Forum instead of this one, so you might check over there too.) Our 1200 sq. ft. stucco is nowhere the challenge your house is, but our climate may be a little more daunting, except we never get hurricanes in Montana ... :-) Our monthly power bill, including an outrageous $40/month just for gas to heat our water, is $125.00. Our household water useage is about $25/month and we irrigate with a pump, so that's covered under the $125.00. So gas, electric and water, including irrigating, all told cost us about $150/month. We're two people in our late fifties. Do a lot of watering but otherwise pretty modest in our habits. We have an electric range. We keep the house at about 65 F in the winter and won't resort to the heat pump for air conditioning unless it gets too uncomfortable to sleep, and then we'll just use it for a few hours in the evening to take the edge off. That'll probably be for a few weeks in August, but who knows. We're conscientious about opening the house up in the morning to cool it and closing it up when it begins to warm outside. I doubt you have that option, but it works for us. Good luck, Mark

dabbindan, Yes, I got a Bryant system and they are indeed 100% the same as the Carrier ones. Only the brand sticker is different. So get a quote on the same models from each side and pick the cheapest. As for the heat pump vs a/c... heck, if you are that unsure about the heat pump reliability with it turning on and off all the time, just use it as an a/c only. But still buy the Heat Pump. If you only use it in a/c mode, then it is using the same mechanical components as a normal a/c. The reversing valves just won't activate to heat mode. With regard to the 90 furnace though, I'd be more concerned over getting an above 80 high efficienecy furnace's reliability than the heat pump. Make sure you ask about and read up on their known quirks and issues too. Just cause it's just a burning flame doesn't mean it doesn't have LOTS of complex circuits and parts that can fail as well. I know the 80 AFUE furnaces are simpler and more reliable than the 90+ ones. That difference might be small, but it's no smaller than worrying about a heat pump's reliability. Hope that gives you some more to think about...

Niabiaxxmoi, Upkeep on a ground-source heat pump is going to be a lot higher than on a gas furnace/air-air AC combo. A furnace has much lower complexity and higher economies of scale of manufacture. Note that zoning is not something that will save much money in a well insulated and sealed home compared to a poorer structure. I am going to disagree on some points. It is better to knock on doors than place flyers; ask any professional community organizer. Best to do both door to door and flyers. Just be sure to have a woman in the mix for door-knocking. Other women are much more apt to open up for a woman than a man if they are alone. Stay away from the mailboxes. Some mean-spirited person may rat you out to the Postal Dept. No, they won’t send you to Gitmo, but the max fine is the postage that you’d use to mail the flyers. Take into account the difficulty of an added flue pipe for an added gas water heater when counting your chickens. It should not be a problem, but on rare properties, it can be. OFF TOPIC WARNING: This may be splitting hairs in some views, but New York State does not have property tax. All property tax is local and it is not particularly high in New York State (I.e. the real New York.) National average property is about 1.3%. There are lots to quibble with in these numbers since there are so many exemptions and technical differences. According to my information, New York City and fellow travelers in the far Southeast (the other New York) has a very low property tax expressed on a % basis. That is part of the reason they must constantly siphon off revenue from the rest of the state to support themselves. They have a tiered system for residential properties. Adjusting for other vagaries, the rate varies from 0.6% in Brooklyn to 0.8% in NYC. I believe that is for homes with 1-3 families. If there are 4 or more residences in a building, the rate skyrockets. By contrast, in Monroe County, on the North coast of New York, the effective tax rate is more like 3%. In Rochester, more than half the property tax goes to public schools. Of course the assessed value of the property plays heavily into the actual dollar amount that you pay.

There is something terribly wrong with your description of what the house will be vs the heating load of 9-10 tons. A "ton" of heating or cooling load is 12,000 BTU/hr. The house you describe is not what you'd call "huge" anyway, at just 3300 sq ft main plus another 900 over the garage. Finally, such a high heat load clearly is inconsistent with any house that is "superinsulated." As others have pointed out, you need to have someone competent do a detailed heat loss calculation for the house, using all details of construction, U values and sizes of all windows and doors, and anything else that affects heat loss. Most HVAC contractors either don't know how to a really good calculation or won't take the time to do it, relying instead on rules of thumb. For comparison, my superinsulated house in central NH (climate zone 6), finished in 2011, has a footprint of about 2000 sqft, with two levels, for a total gross square footage of about 4000 sqft, close to what you propose, but with a different configuration of course. It is heated by GSHP (standing column well design). The regional distributor of the unit installed and two of their "approved installers" all came in with around 4.5 tons of heat load, which they proposed satisfying with a 5-ton unit, even though I had given them all details of the house and my own spreadsheet showing a heat loss of somewhat less than two tons. In the end, I bought the two-ton unit. The tables for the unit showed that at the air and water flows to be used, it would deliver over 25,000 BTU/hr of heat in second stage, or about 75% of that in just first stage. As it turned out, the unit keeps the house at 70 F throughout the winter, in just first stage. My best calculation of heat load when it's 0 F outside is about 19,000 BTU/hr, somewhat better than my last run of the spreadsheet prediction. In summer, cooling mode provides AC; the unit is really loafing then, as the cooling load, worst case, is less than one ton. Your first money ought to go toward making the shell of the house truly "superinsulated." There is a wealth of information on how to achieve this, but still relatively few builders with experience beyond building house just "to code." I followed the subject of building science and superinsulation over a span of about 30 years, leading to my specifying the construction of my own house. I found a local builder interested in doing something new and different, and we worked well together. I didn't tell him how to frame, and he followed the design and my input on air sealing and other details. The house has a double exterior wall frame, typical of a great many superinsulated houses. The outer wall is 2x6, inner 2x4, with a 3" gap between. The insulation cavity is 12" thick, filled with dense pack cellulose. Windows are a mixture of triple pane casement and fixed glass. The foundation walls have 2" of rigid foam inside, another 2" outside. If I had to do it all over, I'd just put it all on the inside, as I had to cover that with 2x4s flat-wise and sheetrock over that for thermal and ignition protection, as required by code. The lower level slab is poured over a 4" layer of foam. The house is air-sealed to a high degree of tightness; the final blower door test came in at about 0.8 ACH50, vs Energy Star requiring 3.0 or better. Fresh air for human health and to keep interior humidity from getting too high in winter is provided by an HRV (heat recovery ventilator). The incremental cost of making your new house truly superinsulated class isn't all that much. I'd give serious thought to skipping all that expensive radiant floor heating. As someone else pointed out, in a highly insulated house the floor surface temperature won't get warm enough for it to feel warm underfoot. That wouldn't happen until the floor got into the upper 70s, and with little place for the heat to go the whole house would warm up to close that temperature, which most people would find stifling. Save the plumbing cost of radiant floor heating, and put it into the building shell and windows. Do your reading, get someone competent to design the shell and do a really good heat loss calculation, and you likely will not exceed the capacity of a three-ton unit. One final thought - give careful thought to isolating the living space over the garage. Such rooms typically are hard to heat and leak too much air from the garage, something you really don't want.