This thread has spawned from the Due Diligence thread. I have received three geo quotes and they all very greatly in price. Maybe it was lack of information I gave to the person giving the quote, maybe it was lack of geo knowledge, maybe it was a lack of sips envelope knowledge or maybe any combination of all of them. Here are a few of the specifics about the house:

2750 sq ft on main and upper levels
1385 sq ft in unfinished walkout basement- planned for hydronic radiant heat
1385 sq ft in attached garage- planned for hydronic radiant heat

The walls will be constructed of 6 1/2" eps sips panels on the main level, upper level and garage. The basement will use 8 5/8" eps sips panels below grade. The roof will have conventional trusses with spray foam and blown-in insulation above that. I plan to use taller sips panels and hang the floor trusses from the top of the wall trying to create an unbroken barrier where the floors come together (basically no rim joists to seal off).

The property is located in central MN and the ground is primarily sand. Elevation is 950' The lot is heavily wooded with many mature trees.

The house has approximately 400 sq ft of window area with a majority of the area on the westward facing side of the house. The windows are either Marvin Integrity or Andersen 400 series low-e windows.

Below is the listing of the information I got from the 3 most recent quotes for the system. I don't quite understand why there is such a variance in the quotes.

Quote #1

	If we were to do full Geothermal system.  Includes all sheet metal, Wirsbo
	in floor, ventilation, Carrier 95% furnace, Water Furnace EZ 36 split,
	Water Furnace EW 60 for radiant load,  all storage tanks, plumbing of
	hydronic system, and controls.  Includes all material and labor for loop field
	and $ 5000.00 for excavation
30,000.00	For us to supply all Equipment for Geothermal system,  loop material
	and labor
4,053.00	Approximate annual cost to heat, cool, and hot water for your house per
	year with conventional system.  Includes heating garage
869.00	Approximate annual cost to heat, cool, and hot water for your house per
	year with Geothermal.  Includes heating garage
	It will take about 6 years 4 months to pay for geo upgrade
	Approximatly $ 3800.00 in rebates
	Heat loss figures used for sizing and fuel costs
	107566 heating btus  31634 cooling btus

$51,612

Quote #2

GeoComfort EZspllt Dual Capacitywith l0 year complete parts and labor warranty
GeoComfort EW water to water unit wtth 10 year complete parts and labor warranty
High foam house keeping pad
2005R Fanteck air exchanger
26-992 pump geo-link flow centers
Geo-link hose kits
100,000 bTu York modulating back up furnace for off peak electric rate.
Ducting
(30) Supply air vents
(16) return air vents
All duct woric and fittings for supply and rotum tnink lines
Two forced air zones main & lower and upper levels
Venting:
(1) Dryer vent with d.yec box to minimize space between dryer and wall.
(1) 3’ concentricvent (Iorbackupgasfurnace)
4’ bath vents, duct wort insulation and fittings (one vent for laundry room with no window)
(1)6’ hood vent, duct work insulatIon fittIngs (300 CFM or less)
(2)6’ vent, duct work insulation and fittings (For airto air exchanger)
Controls:
4 (1) Honey well IAQ total comfort control
4 (1) Honeywell IAQ touch screen t-stat with humidity, dehumidification and outdoor temp display

1000 FIeld Heat exchanger
(6)600 foot horizontal loop
(12) 300 colts SDRII. 

Dirt work to header loop field
main supply and return trench up to 60’ from house
(1) Complete fill, flush, purge and antifreeze
Labor to Install the above

Gas & Piping:
All drain line from equipment to floor drain.
Geo-piping from loop field to units.
insulation of all gao lines m side building.
City mechanical permit

 $36,746.00

Quote #3

Supply and install a 4 ton Heat controller forced air heat pump with desuperheater

Supply and install a 4 ton Heat controller water to water heat pump with desuperheater

Install 3 zone supply and return ductwork

Plumbing of Desuperheater to hot water tank (water tank by others)

Installation of ductwork for bath fans and clothes dryer

Installation of heat recovery ventilator for the home

Installation of non-pressurized flow center

Necessary plumbing of loop field to heat pump

All associated control wiring (power connections by electrician)

 

 

Price for the above mentioned work                                                                                             $34,900.00

 

Installation of 2750 square feet of in floor hydronic piping to include 2” foam with 3 zones. Installation of buffer tank, expansion tank, controls for 3 zone system, variable speed pump.

 

Price for hydronic installation                                                                                                                       $15,600.00              

 

 

 

This system would require the installation of an 8 ton horizontal loop field to include the following:

 

Design and install a 8 ton horizontal slinky loop

Trenching, pipe installation, backfill

Run 2” header pipes into mechanical room from loop field

Flush and fill with methanol/water mix

 

Cost for loop field installation                                                                         $12,000.00

 

$62,500


I apologize for the formatting but I tried to copy and paste what I could to avoid error. I probably could do much more investigation with each of the companies that are providing me quotes but I just am having a hard time with the variances of these numbers. I'm hoping someone here can help me weed through the information.

Thanks for taking time to review this.

Wow, such loose specs.  

Do they all agree on how much heating you need (btu/hr design load and then tons)? 

I would have quote #1 print out the entire Water Furnace comparison of geo vs fossil (WF software makes this easy).
#1 is way too optimistic about the savings.

Does #2 include the radiant floor?  If not, #1 and #2 are the same price.

Exactly how many feet of pipe in how many feet of trench at what depth?

COP and SEER?

Any other choices in terms of fuel - nat gas, oil?

Will they agree to build to IGSHPA standards?  Certifications?

Can we start with the Manual J load? I don't understand the two that want 100mbh furnaces.
#3 seems more knowledgeable.
Hydronic adds a hefty bill to overall price. Might want to do that your self, but coordinate with installer.
Look up John @ Free Source Energy and see if he's close enough to help.
Good luck,
J

107,566 Btu/Hr seems high for a SIPS home. Have all three given you the heat loss/gain information?

Bergy

Thanks for the replies. Quote #3 did say that the heat loss for the house was 44,000 btu and the heat loss for the garage was 30,000 Btu. They did not mention anything about heat gain. I neglected to put that in my original post. I did not get heat loss/gain info from the person that did Quote #2. Quote #1 gave an estimate of 107,566 Btu for heating and 31,634 Btu for cooling. They did not mention anything about heat gain. All of these quotes were for closed loop water source geo systems. I have contacted another geo outfit that does DX systems and I am waiting to hear back from them. These price quotes that I have been given wil basically price me out of the geo market. I don't know if these are really the prices that I should expect to see or if the people I have talked to really aren't "qualified" to quote me an appropriately sized system for use with sips. I don't mean that as a bash to the people that gave me quotes but either they don't really know sips or I am totally underestimating the actual size of a system that I think I need. Maybe it is the use of 2750 sq ft of in-floor heat that's causing such a high price. There are areas where I can drive the cost down by doing some of the work myself and with help from friends and family that have expertise in certains areas. When it comes down to it and the time is here for me to choose a system, I'm going to have to bear down and ask the tough questions. Thanks again for the replies.

One says 107,566, one says 74,000 (but wants to install 8 tons) and one doesn't say. That's not a good start.

You might find a designer at http://www.igshpa.okstate.edu/directory/directory.asp and tell them that you want them to design and spec the system and then use some mix of an installer and you to do the work.

If you don't have natural gas and are going to stay awhile, I'm not sure you can afford not to use geo.

IMO, radiant floor is mostly a comfort issue and is fairly independent of geothermal vs fossil fuel.

A designer could tell you if open loop would save money.

Heat pumps move alot of air and a proper air distribution system will eliminate temperature differences in the structure, also if you have more than one floor you will need to run the fan on continuous most of the time to prevent stratification. Zoning is a waste of time and $, put in a 5ton 2spd with good ducting and a good sized field . The hydronics can be done off the hot water tank that the superheater takes care of. I install this type of installation often with no complaints and its compact, efficient and cheaper. I live just north of you across the border and have done similar sized homes that don't match your efficiency. $ 29,000+tax CND ,hrv included.Good luck

I disagree that zoning is "a waste of time" in multistory structures. While I agree it is possible to configure ductwork to properly distribute air according to individual room loads, what works in January likely won't in July, and in many structures what works in the morning won't in the afternoon or evening if there is significant west or east glass.

A desuperheater recovers at best 10% of the units nominal capacity, so unless the hydronic load is very small, the desuper will not materially contribute to meeting the load. Circulating domestic hot water through a hydronic system raises an issue of stagnation, and my understanding is that it violates code in some jurisdictions.

You get what you pay for and your mileage will vary.