Geo costs vary significantly by region. It really is hard to give a ballpark but you might throw in location as this gives some guide.

The different approaches are a little baffling. Your backup should depend on what your options are and your cost. Generally geo makes sense in a cold climate without access to NG. Then your best backup is usually electric but what other fuel do they plan on using?

I'd say in my area, 10 tons with electric backup would be about $100k

Thanks David.We live in Northern Lower Michigan, just above the 45th parallel. We do not have Natural Gas and Propane is our fuel source other than electric. My understanding is that we will seldom need the back up heat. The boiler set up seems like it will give us much more control over the basement climate and an endless supply of domestic hot water but it also seems like it will cost us a lot more in the long run vs. something like a Marathon Electric HWH. I also should say that your number is higher than any of the three I have gotten so far. This makes me less comfortable with the lowest number as I see many warn about cheap installs!

My area does geo rarely which is why it is so expensive. You can't really compare to your area. Why wouldn't you want your geo to preheat the water?

At most people's electric rates, propane costs more to run so it seems crazy to pay more to install propane unless you are worried about power outages.

We do want the Geo to pre heat the water. Outages are often enough for us to probably install a generator that will power one of the two units so that we avoid damage in the winter. Do you think it would be common for the boiler back up to run quite a bit more than the electric back up? Again, just nervous about the 30,000 difference!

Dboyer

Not a Geo expert but the idea of 10 tons for new construction that I assume will have the best building and insulation properties really sticks out.

Yes, price is important but you must qualify your selected contractor both for Geo and zoning.

It would seem that from an operating cost position that electric backup would be the best choice. Use propane perhaps for cooktop and generator use.

Other than that which is not much, I don't see how a forum member could properly advise you.

IMO

Thanks tigerdunes. I realize it was a long shot. Just getting more confused the more I try to figure it out. They are all sizing it about the same (it is a big house when you include the basement, especially). Maybe on a slightly different note, do you have an opinion on carrier infinity controls vs. a Water Furnace system specific control (don't know which one, maybe the XL950?) that would be used on a Trane Earthwise T2GY unit? Part of my concern with the price difference is the control we will have over each zones environment.

Dboyer

Carrier Infinity zoning controls are generally regarded as the best on the residential market. I have not heard though that they are used on another manufacturer's HVAC system. With a very intricate system like you are considering, it is the sophisticated controls that are running the system not the thermostat.

As I said previously, you need to thoroughly vet your dealer's qualifications and experience (including ductwork design and sizing) in both Geo and zoning. Go visit completed jobs the dealer has performed.

IMO