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Bill Rittenberg
Registered Users
New Member
Posts:1
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| 04/20/2008 9:14 PM |
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Thanks for all the expert comments on this board.
We're planning to install a closed loop geothermal heating and cooling system for a new 3500 sq ft meditation hall in mid Michigan. Our first bid before we knew anything was for a 10 ton system, possibly too big. The heat load was ~ 138,000 BTUs and the cooling load was ~104,00, but the contractor didn't have all the right figures in making the calculation. Anyway, after much research (confusion and obsessing) we're now somewhat better informed and plan to approach a variety of contractors , including the first one, for new more accurate calculations and more detailed bids.
We have many questions, but I wondered if the board had comments in two areas.
1) We're considering introducing an HRV or ERV intp our system. The Waterfurnance area rep recommended a RenewAire ERV, saying it's design was unique, much simpler than other ERVs with no problem of condensation and ice buildup. Does anyone have any comments on the payoffs and problems with using or not using an HRV/ERV, and any experience in particular with the Renewaire ERV?
2) We read that a vertical loop is more efficient than horizontal, that there's a
risk that the soil temperatures for horizontal could change
irreversibly over the long term from the operation of the system, and
of course the trenching for horizontal would cause much more soil disruption and use more space than vertical loops . The
"gravel" in the surface soil seems to include some sizeable sharp
rocks, and that worries us too about choosing horizontal loops. So we're inclined maybe to choose vertical loops if their affordable, but we don't know if our thinking is sound.
I believe our water table is ~ '28 feet (need to check that). From our well digging log, the soil composition at different depths were
Clay and gravel 0-45'
Clay 45-90'
Shale 90-145'
Sandrock & shale 145-215'
Shale 215-230'
Shale & sandrock 230-265'
Shale 265-320'
When I called around, several well diggers suggested the depth of the vetical loops might be between 150 and 200 ft in our soil conditions, and the cost difference between vertical and horizontal might be somewhere between $300 and $800/ton:
Vertical/ton Horizontal/ton
#1 (GCD) $5 to
$16/ft ?
#2 $1,890 175
#3 $2,200 175
$1,600
#4 $2,000-1,800 150-200 $1,700
#5 $ 2,000 150 $1,300
I feel I'm operating very much in the dark on this matter. Any comments on the desirability of vertical over horizontal, the suggested depth for our vertical loops, and the possible cost difference between vertical and horizontal would all be much appreciated.
Bill
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tuffluckdriller
Registered Users
Basic Member
Posts:436
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| 04/21/2008 10:54 AM |
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A couple of things...
On the ERV, I've never known of one to not have an issue with condensation/ice buildup. If it is removing heat from air, there will be condensation. The only way not to have condensation is if it re-heats that air via electric or fuel, or that the relative humidity is so low, that there's no water in the air to condense. It's just a principle of heating or cooling air.
With the closed loop, you'd save money by having an EarthLinked DX geothermal system installed. You'd only need 100' drilled loop per ton. This will be lower drilling cost. You'd have a lower installed price for a higher efficient system.
Contact Mike Dilling. He's the sales rep for your area. He'll know what installer to recommend in your area.
Mike's info is:
www.heawarsaw.com
mike@heawarsaw.com
Tel: 574-269-2603
Fax: 574-269-4188 |
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Clark Timothy (clark@pinksdx.com)
VP sales, Tuff Luck Geothermal Drilling
Geothermal, Heating and Cooling that's Dirt Cheap! |
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