I have a 2400 sq ft home with a Oil-Fired Hydro-Air System (boiler plus forced hot air w/ two air-handlers) w/ Air Conditioning.  I have been trying to get some estimates for a DX Geo system.  I have received the following 'ball-park' figures.  $60,000, reusing my current air-handlers.  I think this guy is nuts.  I also received $6000 per ton installed.  So for a 4 ton system about $24K, this was with two new air-handlers as well.  I also received $32K for 3.5 Ton system reusing my air-handlers.  Two installers were a bit concerned with the current size of my duct work, to see if it could carry enough cfms for the btus I would need.  I'm guessing the costs around 25K-30K are the correct ball-park.  At current oil costs with some inflation built in it will pay for itself in about 7 years, including interest to finance it for 5 years.  Oil would really need to skyrocket to pay anymore quickly.

Any thoughts on these figures? 

Once installed can a 'regular' HVAC person support any compressor repairs?

I'm not at all sure how either a single 3.5 or 4 ton system can be economically integrated with 2 air handlers. I guess it could be done with a single water-to-water geo unit sending water to coils retrofitted into each existing air handler. That'll be complex and expensive.

Given your relatively low tonnage is there any way to get down to a single air handler and zoning dampers? It might take a supply and return trunk run up through a closet, reducing that closet's space.

Regarding "compressor repairs" - Compressors themselves fail rarely. What you are asking is whether a typical airsource contractor can service your geo system...maybe, upon occasion, but I wouldn't bet on it. You call in with a no heat or cool complaint - could be a contactor, reversing valve, refrigerant leak or some other failure a typical airsource guy can deal with...OR it could be a pump, pipe or other geoside issue; the airside guy isn't gonna have a clue but to stay in the game may well start replacing perfectly good but expensive parts (such as the compressor) that aren't actually at fault.

Sure a "regular" guy might be able to service your geo system...but is that what your REALLY want?

Keep inquiring wih DX dealers, one of the beauties of the Earthlink system is "variable" refrigerant capacity making it perfect for multi tasking. We've even contemplated cooling a home while simultaneously heating a pool and then shifting to the ground sinks when one or the other (but not both) is satisfied.
For water source, depending on the quality of the equipment you select you may find that a couple smaller single stage water to air units are not to much more than a larger water to water unit with fan coils and could have better efficiencies and warranties.

SkiHawk,
The location of your air handlers would have an impact on our advice. Are they both in a basement, 1 upstairs 1 downstairs...?

I am in Hartford County.

I have one air handler in the basement (serving the first floor), and one in the attic (serving the second floor). I have hot water pipes running up a rear closet and then into a second floor knee-wall attic, an then up to the attic above the second floor.
Thx.

Well that certainly limits you to the ideas above. While I often would agree with GeoFan about 1 appliance versus 2, a zoned water to water system would actually be 3 appliances versus two. Both would have ups and downs.

My thinking / hope here is that I could have a DX GeoPump located in my basement, and then have it feed two zones (one handler in basement / one handler in attic). I currently have Hot Water lines running up to my attic, couldn't I just have refrigerant lines running up there with a Geo System (just like I have refrig lines running from my A/C compressor)? Expanding my thought further, couldn't I have both the HW line (from current boiler) and Geo Refrig lines running to 2 air-handlers? With the HW lines being the backup heat? I read in another post that I may not be able to run both lines at the same time to a single air-handler.

staged properly you can absolutly have your hydro coil as your second stage . To adress your price concern I am in the middle of a job being done in Farmington for my parents. 5 ton single dx with a desuperheater tank new lineset and variable speed airhandler with a resistance back up , hitting up every contact I have for there best price and doing all the controls for free the price is just over 20k . So considering that your 6k per ton quote was very good as long as its a real quote not a rough estimate to be adjusted with overages and a good airhandler variable speed, heatpump thermostat with an outdoor temp sensor to control the stageing and the company is not a fly by night type I say go with that . and talk about a desuperheater tank with them they are well worth it

With EarthLinked DX, you can't run more than one refrigerant air handler from one heat pump. If you want more than 1 air handler, you'll have to heat and chill water, and then use hydronic air handlers. You'd most likely be able to use the existing water lines, but may not be able to use the current coils. This is because those coils are (at least should be) sized for higher temp. water. If you send geo-heated water to those air handlers, most likely the coils need to be bigger, and the fan a different size.

tuffluckdriller & geofan, thanks for the info.

tuffluckdriller could I have a geo pump/air-handler combo unit, one in the basement and one in the attic to support my two floors? Can I run refrigerant lines all the way from the ground to my attic? Can I run two geo-pump/air-handers to the same ground field?

It seems like I might be loosing a lot of efficency if I use the geo heat to heat water for hydronic air handlers.
Thx

You could run two small (1.5-2 ton) closed loop conventional geo systems off a single outdoor array / field. I doubt you'd be able to do that with DX since each system's refrigerant charge likely needs to stay isolated to that system

This is how I'm set up.  My 3 ton and 5 ton units run off of a single water loop, with the loop sized at 8 tons.

Best regards,

Bill

In this case, I still think your best bet would be two water source units. Curiously having the DX heat/chill water takes away it's advantages over water source (as it puts the middleman (water) back in to the scenario). You can have 1 package up and 1 down replacing each air handler and using electric resistance coils for back-up. Using an oil anything for back-up simply makes it cost more to operate.
To answer another question of yours, you can run any type of line or even duct work from your basement to the attic, though some DX or split system water source units may have a maximum lift and or distance between coil and pump (25-50 feet). You could run water lines from a horizontal loop field just as easily.