Building a custom home in southern Utah: ICF construction (footers to roof) with ~3000SF per level (3000 SF upper conditioned and 1800 lower conditioned). We have received two bids for a standard Geothermal System: 11 ton system ~ $67000!!! I questioned the heat/cool load calcs to no avail. Just got another bid from an ECR Earthlinked installer: 6 tons ~ $25000-30000. Certainly the ECR bid seems more reasonable: installer voiced understanding of the ICF benefit (factored this into the calculations). I reviewed past topics on Earthlinked systems and would ask for input on homeowners' experiences with these systems. Also, I have heard of system specs being off by a few tons; does the 6 tons sound reasonable? (no south facing glass, 8 inch ICF, insulated slab, R40-50 in attic). Thanks

With energy going crazy, did you ever think about down sizing your home? Plan on getting hammered in the years ahead for energy........

That's a considerable difference in tonnage, I wasn't even aware they made 11 ton residental systems. Perhaps they are talking about 2 seperate systems with a combined tonnage of 11 tons. If there questions about the heat loss calcuations for your house, perhaps it's worth the investment in buying some heat loss calcuation software. Link You don't want to undersize the system, but also its a waste to oversize it too. With the differences in tonnage calculations, I'd spring for the $49 program.  

neotobeo,

Just wondering, how far south are you? St. George area?

Your ECR dealer should be able to provide you with load calculations. If you'd like, you can email me a pdf of your plans and I'll do the calculation for you. I'll bet the 6 tons is just fine.

Based on your house size, the 11 tons seems completely out of whack. Way oversized. However, without doing the load myself, I'm just speculating...

How does the earth loop copper stand up over time? Dosen't contact with acidic  soil tend to corrode the copper as apposed to the plastic in the other systems?

If the ground pH is below 6.0, then there needs to be a CPS installed. This is an impressed current cathodic protection system. It constantly bombards the copper with electrons. It will give the loop at least 50 years before it starts eating at the copper. 95% of the United States is above a pH of 6.0. Just take a soil same to NRCS. They'll test it for free for the pH. I'll bet you're around 7.4-8.4. But, you could be in an odd area... Just have it tested. If the pH of the soil is above 6.0, copper will exist naturally (the same place it comes from) in the ground without any corrosion problem.

Tuffluckdriller:

Do you do installs of the DX system in St George?

I have a dealer that can. He's in Hatch, by Panguitch. I don't know the ECR dealer in the St. George area, but I'm sure he'll do a good job, too. If I needed to, I'd send my drill down that way for a few jobs, but there is a Sales Rep/driller right in the St. George area that most likely can get the drilling done for you.

tuffluckdriller, What kind of drill rig do you use for DX geothermal? What manufacturer? Are you happy with it? jay

Earthlinked heat pumps in my area yeild about 20% more heat than closed loop water source. That can explain some size disparity, but not all. As far as price disparity, 11 tons is a lot of extra duct work + extra drilling and twice the equippment.
No way you can stop at 2 bids with this big a difference. Let's hear what your third bidder suggests.
Good luck,
Joe

I have a sonic drill. It's an SDC-550 crawler rig from sonic drill corporation. I love the rig. We can drill ANYTHING and guarantee a grouted, total depth loop. When I say total depth, I've known some drillers who drill down 300' deep, but then the hole has caved in down at about 180'. They just cut the loop and call it good. I don't do that, and I don't need to do that.

I would never get anything other than sonic technology. That's not to say I'd just stick with sonic drill corporation. In fact, I'm looking in to possibly getting a 2nd rig. If we do, it'll be from sonic-sampling. It would be a newer rig they've developed called the Compact RotaSonic (CRS). The price tag for it, with all necessary tooling, grout pump, etc., would be about $350,000. The SDC-550 with all necessary equipment has a price tag around $750,000.

Sonic drilling is really the way to go for these. It's awesome how they work. We also install water loops for the water source systems with it.

Clark,

Do you drill in rock?  The reason I asked is because I talked to Sonic Sampling people about this for the 100' Earthlinked loops and was told rock was problematic for their equipment.

The speed, safety and cleaner job site make sonic drilling attractive if it is not restricted to certain geologic formations.

Thanks.
Dale

With our sonic rig, we've drilled solid granite, solid sandstone, solid basalt, clay, shale, sand, gravel, cobbles, boulders, etc.

The CRS from Sonic Sampling is supposed to handle the 100' in rock. They do have problems with their compact sonic in rock. It's not able to rotate and vibrate at the same time, which is why they have the problems...

I'm still looking forward to seeing a CRS demonstrated in the states to show it'll drill what I want it to.