I know we've got installers on here reading and commenting, so I'll query them as well as the people who have done this.  If someone wants a horizontal system and a geothermal expert designs it and tells the customer how to dig the trenches, how much cheaper, if any, is the installation?  Is the customer still the person who does the back filling since the way it's back filled can affect the efficiency according to what I'm reading?

I've thought about going this route if it might be any cheaper.  I can certainly rent and operate either a trencher or backhoe to dig trenches and I've got plenty of room to work in. 

You sir should save a bundle!!! Labor and equipment are very expensive. I have done all sorts of modified projects for people based on their skill set.

We let the homeowner dig or sub-out the trenching directly. It is an open ending question on how much it will save as there are way too many variables.


Alternative Carbon Energy Systems, Inc. (A.C.E.S)
IGSHPA Accredited Geothermal Installer
Serving Upstate New York including Rochester, Buffalo & Syracuse

ACES-Engery, do you let the homeowner backfill too?

Sure thing, usually if the homeowner has the ability to run a excavator, they have the ability to back fill.  We are there and build into the price a fee to supervise.

Not a problem, we let the customer dig and backfill. If he has the skills, not a problem. It is important to accommodate their needs and save them some bucks. We are onsite anyway when we prepare the slinkys, enter the pipes into the building, or do other stuff which needs to get done anyway. Never had a problem with it.

We let our installer do everything. If I (or my sub) did the backfill, I don't know if the installer would have still offered us the 10 year pipe and labor warranty against leaks. The warranty was important to us. If the warranty is unaffected, or if the warranty is not important to you if it is affected, it would be nice to save some money by doing some of the work.

There wouldn't be much savings if the prime contractor has to arrange for backfill.

Does anyone use water to consolidate dirt around loop piping? I have the idea that once the pipes are covered in 6 or so inches of backfill, liberal use of water might displace the air entrained in loose fill around the tubes and ensure pretty good soil - tube contact.

Or am I all wet, so to speak???

Seems reasonable to me. Our 5' deep trenches settled significantly after 7" of rain over a few months. We then finished grading. Then it kept raining making low spots again. Did some more filling in of low spots. Hosing down the dirt every several feet doesn't seem to be much different to me than tamping dirt every so often when doing other projects. May be more time consuming for the installer, unless the homeowner can pitch in. Wish I had done this. Keeping dirt piled up over the trenches is hit or miss in terms of settling, but it is better that than spreading out the "left over" dirt and needing much more later.

I think I'd consider heavy watering at 2 or 3 intervals during the backfill; assuming water is economically available for the purpose. I see this being more helpful in clayey / silty soils and less so in very sandy conditions.

It has been observed before that horizontal loopfields take a year or so to fully settle and realize maximum performance. That can be a bitter pill to swallow during the first year of operation.

Watering in the lines or letting the trench flood with slurry is an excellant way to ensure contact... However this is a horrible option if compaction testing is required. In a residential application I think it would only help.

Thanks guys. I'll go this route if I don't do open loop. I got an estimate in the mail today from a local HVAC company that came out to do a J. They do everything inside the home and do nothing outside. I could pay someone to design the outside loop for me or get the program and do it myself, and then dig the trenches myself. Pay a plumber to put the loops in (or learn how to do it myself) and bring the pipes into the house. From there, the company that quoted me this new estimate would do everything else.

Personally, I think the HVAC company should DESIGN the loop too. DOING the outside work is fine for someone else to do (assuming they can do a competent job). Someone needs to to be responsible for the overall "system design" (inside and outside). If there is a problem with system performance, the inside contractor will blame whoever designed the loop (and vice versa). As others have said, someone needs to take ownership and be responsible for the project.

Just to be clear, we let other do the excavation and backfilling (no rocks) but we insist to do the fusing of the pipes. Unless you want to header inside,...