Hi. My husband and I are building a new house. :) We have already made the decision to install a GEOTHERMAL system. We have recieved two bids and, not knowing enough about the world of heating and cooling, especially geothermal alternatives, it is difficult to compare the proposals and make a decision on which contractor to use.
We appreciate any feedback.

Bid #1:
1- 7 ton econar geosystems ultra forced air heat pump with desuperheater for main and upper floor heating/cooling M#GV771-1-UOOO
1- 3 ton econar geosystems ultra forced air heat pump for basement heating and cooling M#GV370-1-UOOO
1- 1.5 ton multiaqua for heating and cooling the bonus room
9- forced air heat registers (basement)
18- forced air heat registers (main floor)
11- forced air heat registers (upper floor)
1- range vent vented to outside
1- dryer vent vented to outside
4- bath vents vented to outside
1- braon air exchanger with master control
1- aprilaire model 700 humidifier
3- air pad
3- honeywell digital thermostat
3- max-aire electostatic washable filter
includes: install all plumbing and horizontal slinky closed loopsystem for the equivalent of 10 tons. excavation is included.
total $: 54,900.00

Bid #2:
Carrier Equipment
2- 50ydso49ncd301 gt-px 4 ton geothermal 2 stage split system
2- 58mvc080-20 infinity 80,000 btu, 3 stage variable speed 95%afue furnace
2- aprilaire 700a bypass humidifier
2- venmar constructo 1.5 air exchanger with constructo wall control
2- carrier infinity stats w/nim control
2- bradford white 50 gal fury electric water heaters
2- honeywell f100 4" media filters
2- warmflo 10 kw plenum heaters
geothermal loop field horizontal field for 2- 4 ton systems
total $38,194.00
also in bid #2
bonus room equipment: 1- magic pak 2.5 ton 60,000 btu self contained unit
= $3,500.00
options:
lennox good equipment
2- g43uf-48c-090 92.1% afue 82,300 btu 1 stage furnace
1- 13acx-036 3 ton 13 seer r410a single stage central air
1- 13acx-042 3.5 ton 13 seer r410a single stage central air
2- aprilaire 600a bypass humidifier
2- venmar constructo 1.5 air exchanger with constructo wall control
=$9,826.00
lennox better equipement
2- g61mp-48-090 94.1% afue 83,000 btu 2 stage furnace
1- 13acx-036 3 ton 13 seer r410a single stage central air
1- 13acx-042 3.5 ton 13 seer r 410a single stage central air
2- aprilaire 700a bypass humidifier
2- honeywell vision pro 8000 7 day digital thermostat
2- healthy climate 4" merv 10 media air filter
=$12,298.00
lennox best equipment
2- g71mpp-60c-090 95% afue variable capacity-variable speed
1- xc14-036 3 ton 15 seer r410a single stage central air
1- xc14-042 3.5 ton 15 seer r410a single stage central air
2- aprilaire 700a powered humidifier
2- venmar constructo 1.5 air exchanger with constructo wall control
2- honeywell vision pro 8000 (3h/2c) 7 day digital thermastat
2- healthy climate 4" merv 10 media air filter
= $15,084.00

Thank you for any insight you may be willing to offer with regard to this info.

System #1 appears to be an almost entirely geothermal system (except for the multiaqua system) and system #2 is a small geothermal system plus a natural gas furnace to split the heating load and 2 x 10 KW electric heaters. These bids aren't exactly apples-to-apples so it's no doubt that you're having difficulty comparing them. Here's my layman's advice, as someone who's currently having a house built with geothermal and had to decipher bids a couple months ago:

- Ask both contractors if they did a manual-J heat loss calculation to size the system appropriately, and check references.
- Ask contractor #1 if your system will condition the air comfortably in the summer. MN like WI is a heating dominated climate so a system that's correctly sized for heating is oversized for cooling. That can lead to excess humidity.
- Ask contractor #2 why you'd get electric water heaters since you'd already got natural gas coming in, and what % of your heating would be handled by the geo, i.e. how much would the natural gas and electric heat come on. Also ask contractor #2 (or a tax advisor) if this split-system qualifies for the tax credit.
- If you go with the geothermal (or even if you don't) consider insulation improvements that can reduce the size of the system needed, which may be more cost-effective than increasing the size of the HVAC system.

Pamela,

In respect to the decision making part of your question, I would like to refer you to Thomas L. Saaty's Analytical Hierarchy Process. It is a good decision making tool. Using AHP, one can compare apples to oranges, effectively include subjective values like comfort and status into the decision criteria, and use intuition. However, you need to know the subject (in this case residential geothermal systems) well in order to make a good decision. Therefore there is no shortcut to learning about this stuff.

I'm not a geo pro. I have a difficult time justifying the use of and the emphasis on gas furnaces in the second proposal. Generally, most of (95% +) the heating needs are met by geothermal systems, a small percentage is usually supplied by electric auxiliary heat. Perhaps the person who provided # 2 bid can offer a good explanation. To me the extra furnaces seem like expensive redundancies, except for in a power outage, the gas furnaces can run on a small backup generator.

As, taco_mel pointed out, the Multiaqua seems to be a non-geothermal heat pump, because its tonnage is not accounted for in the slinky closed loop. I think a geothermal alternative might be a small console model.

I'm sure, as always, knowledgeable and patient geo professionals on this forum will offer their good advice.

Regards,

Masoud

I'm sure, as always, knowledgeable and patient geo professionals on this forum will offer their good advice.

As long as you are not insisting on the "patient" part, maybe I can help......:)
To some degree the advice of other end users vs pros might be just as helpful or more so, but I have a few observations to offer.
As far as "why use natural gas back up", it is often cheaper to run than electric auxiliary (depending of course on gas v electric prices). No problem qualifying for tax credit as long as rules don't dramatically change.
Two bids seem far apart but they really aren't apples to apples.
2nd bid doesn't mention duct work, bath fans, ERV (air to air exchanger), kitchen exhaust nor does it have electrostatic air cleaners but #1 doesn't mention water heaters.
Both mention the Aprilaire 700 humidifier which personally I don't care for with geo (look at Honeywell true steam).
I'd like to see heat loads from both and operating cost projections (which includes the %of heating satisfied by geo).
If you are going geo for sure lets stop discussing all the fossil options from bidder #2 (Lennox good/better/best).
Check references as guys mentioned before and find a third bidder.
May want to consider running your own load calc through one of us contractors on line or a one time license use of software. This will help us help you.
My overall feeling is that bidder #2 dabbles in geo and is a code minimum duct guy. If duct is included in a 15K bid with 2 high end furnaces, air conditioners and accessories......run away as fast as you can. I find it more likely that duct work is itemized seperately somehow.
Good luck,
Joe

Hmm, just curious, why would they install Electric Hot Water heaters when Natural Gas is available? I beleive heating the hot water heater with Natural Gas is more efficient than electric. The Despuerheater can work with either type of unit.  I assume that only one will be connected and the other unit is a reserve.
 

NG is unlikely more efficient than electric water heat, though it may be cheaper to operate. Electric water heater is likely cheaper up front and shouldn't cost much more to operate if fed by a desuper with its own buffer tank

NG imposes an additional cost via its consumption of house air for combustion. (Joe gets credit for reminding me of that awhile ago)

I second Joe's other points - a good load calc and one more bid would both likely be helpful.

I would also get a bid for a Ductless Mini Split system. Like any of these below. FYI, I do NOT sell these, I just feel they are better and underused.

http://www.mrslim.com/Products/main.asp

http://www.daikin.com/global_ac/

http://www.fujitsugeneral.com/

There is a reason why the rest of the world uses these, they are better.

Better than.........?
Better than geothermal always? No way.
A better fit for some applications? Of course (as are ducted units, boilers, woodburners,etc.).
Geo is all over the world as well.
You are a homeowner in MO why would you make an unqualified statement that Minisplits are better and underused?
Has it occurred to you the rest of the world might use these because they heat with boilers a lot and don't have ducts for airconditioning?
Of available systems mini splits are the last I pick because most folks have ducts here. Why would I ask them to pay more for splits when conventional equipment works?
Even if you think they need to be used more (at the expense of others), why would you suggest it on a geo site?
Do you go to Ford sites to espouse the virtue of Chevy?
I don't think you grasp the folly of what your saying, so forgive my over reaction, but you did select a thread where a consumer is asking advice on what to purchase and your pick is a poor one for this application.
Joe