Sorry guys.  I wish I could report that this will not happen again but the older I get...

I agree with Joe.  The difference is the installer.  All of this equipment works great if it's installed correctly.

Sounds like a worthwhile project - I wish you luck with it! To expand on my comment further, I think the issue of incoming water temp is a fairly fundamental one, especially for the uninitiated. When I am answering questions about my system, I'd say the most frequent question that comes up is why I need antifreeze in my loop since the loop is below the frostline and the ground temp is supposed to be "constant". When I explain that the loop temp can drop to 30F or even lower in mid-winter, people look at me as if I have two heads. There is definitely a perception that the incimong water should either be a constant 50F year round, or that it should at least stay above freezing (which the heat pump itself couldn't care less about as I said before). Hopefully you can address this in your book particularly given the target audience.

Hi,

          Interesting that you ask!  You might want to look at Faulty Earthlinked systems forum.  I have had nothing but problems with my DX system

Hello, Just to weigh in on the forum - we've celebrated our 100th DX system install and can tell you from experience PROPERLY SIZED AND INSTALLED the DX methodology is excellent. We've also installed several water loop systems and while they operate well they're a pain to install and cost more to run. The water loop folks keep saying DX will leak - and when it does it will be like Chernobyl - killing everyone within a 50 mile radius. DX systems properly installed will not leak in nearly all ground conditions. But that postulates they'll be properly installed. Unfortunately there are too few folks who "get it" and understand the configuration and field work required. Paul TotalGreenus.com

Define "several" and explain how a water source system is any more laborious to install please.
Note that I have made it a point as have many others here to say all systems are fine; installer is key.
I do tire occasionally of the "we're so picked on" complaints of some predominately exclusive DX installers.
Your exagerations do a disservice to your message.
Joe

Joe,

Sorry it's taken me so long to respond why we prefer DX to water loops. The drilling activities are dirtier than DX with more stuff to cart away, the flow centers and manifolds are more difficult to put together as opposed to simple brazing and high pressure testing, and start-up is easier (for us) using refrigerant than glycol or ethyl alcohol purging. In addition, you need less equipment with DX - the heat pumps are more flexible creating 100% DHW using a full condensing coil. We have over 100 DX systems and ten water loop systems.

I'm not exaggerating what some folks who install only water loops say about DX technology. There's one particular well driller in our region who has actually said what I've written - and consumers who don't know any better have been sold off DX. Every sale is a miracle - let's not give a prospect reason NOT to buy. You're hearing the "we're so picked on" because it's true. Give everyone a level playing field and may the best technology win.

What about acid soil etching the copper pipes? I have heard of problems after 15 years with these systems springing leaks due to pipe corrosion. If you already provided some historical data, I apologize for the repeat.

Posted By Paul Auerbach on 26 Oct 2010 11:03 AM
Joe,

Sorry it's taken me so long to respond why we prefer DX to water loops. The drilling activities are dirtier than DX with more stuff to cart away, the flow centers and manifolds are more difficult to put together as opposed to simple brazing and high pressure testing, and start-up is easier (for us) using refrigerant than glycol or ethyl alcohol purging. In addition, you need less equipment with DX - the heat pumps are more flexible creating 100% DHW using a full condensing coil. We have over 100 DX systems and ten water loop systems.

I'm not exaggerating what some folks who install only water loops say about DX technology. There's one particular well driller in our region who has actually said what I've written - and consumers who don't know any better have been sold off DX. Every sale is a miracle - let's not give a prospect reason NOT to buy. You're hearing the "we're so picked on" because it's true. Give everyone a level playing field and may the best technology win.

Sorry Paul, 
I can't abide by DX over water source propaganda.
Water source in my area goes 150'/ton vertical while DX goes as high as 600'+ for 5 tons. This is not a huge difference.
Horizontal loops for Earthlinked for example run in 125' x 4' trenches/ton while my slinkies run ~110' x 30" wide.
Can't hang with the less mess argument.
We also have a fairly recent post from a DX distributor who says DX designs for a higher percent of load than water source due to ground freeze (northern climates) which creates larger foot prints/tonnage.

I have no reason to suspect you are not one of the good guys, but can't let DX claim the moral high ground.

While you mentioned our flow centers, manifolds and antifreeze, you neglected to mention the nitrogen, oxygen, acetylene, braze rods and things unique to your product.....Oh and 30ish pounds of HCfCs.

BTW wish all you guys would lean on your manufacturers to get recognized by the ICC and answer the question of freon leak detectors due to the amount of HFCs in small resi systems.
Blame them for not taking the steps to legitimize their products.

Personally I like the product and think it has a place. I do not hang with the copper decaying in soil propaganda as it is in the soil here in MI naturally.

I also can tell you it is more expensive here than water source (unless I do not charge for the installation man hours which are greater). Certainly does not make that true everywhere.

I support dealer over product. 110 installations demonstrates your real expertise.
I'm cool with both of us backing our primary products and serving our customers the best way we know how.
Be well,
Joe

I echo a low concern with buried copper lines.

I'm attracted to the simplicity of DX as well as potentially better efficiency, but I share Joe's concern about the much higher volume of refrigerant.

I believe the future of HVAC lies in variable speed modulating compressors able to drop down to 25% or less of full load. Until DX works out the resulting refrigerant velocity and oil migration issues, it will remain on the margins.

If you have low PH in your soil , it stands to reason that over time you will get metal migration/etching. I've been told by people in the Northeast that DX buried copper for 15 years sprang leaks losing freon to the ground. The system was costly to replace. I am really curious about the low concern here. What history data can you provide to counter what I've heard? Why would I do geo with metal when hdpe can last 50 years +.

Posted By gonegeo on 28 Oct 2010 09:23 PM
If you have low PH in your soil , it stands to reason that over time you will get metal migration/etching. I've been told by people in the Northeast that DX buried copper for 15 years sprang leaks losing freon to the ground. The system was costly to replace. I am really curious about the low concern here. What history data can you provide to counter what I've heard? Why would I do geo with metal when hdpe can last 50 years +.

gonegeo,
There are 30 year old systems operating in MI.
It is true that some soils are not suitable for DX lines. First step in installation guides of two different systems I'm trained in is check ph. If it is outside of parameters a sacrificial rod is installed (much like a water heater) although one distributor told me privately he simply wouldn't "go there". Earthlinked had 25 year loop warranty last I checked.
Hdpe if backfilled with sharp gravel or boulders would expand and contract its way into leaks after a while.....
Like anything else, if manufacturers' instructions aren't followed, bad things happen. It's not the product or manufacturer's fault, it is the dealer.

Sooooo...........pick a good dealer and everything else will be less important.

Hope this helps.
J

I think the question is "if" you have low PH in your soil.  A soil PH below 6 in the United States is rare.  In Texas, all our soils tests for the DX loops have come back between 7.5 to 8 which is covered by the Earthlinked warranty.  I have talked to DX installers around the country who have installed thousands of the DX systems and I have only found 1 instance of this type of condition actually happening in the field.  It was in the Cleveland area and the home was sitting on top of an old lake bed that was basically a peat bog.  In this instance, the installer simply didn't do his due diligence when evaluating the job site.  If he had done a soils test and followed the manufacturers recommended installation procedure and installed cathodic protection on this job, it would not have had the costly expense of replacing the loops.

Within the past year or so, Earthlinked has tightened up their installation requirement even further by requiring cementious grout for the loops.  Cementious grout is alkaline and anything aklaline will have a high PH.  So, in the ground, the copper loops are even less susceptible to this problem because it is encased in a high ph cementious grout.

Here in Texas, copper water pipes were required by code for eons until pvc and pex water supply lines came along. No one around here had heard of this problem until the folks pitching plastic water loops for geothermal started talking about it. Everything I have been able to dig up (no pun intended) on this matter indicates this is an issue driven by DX business competitors rather than an engineering issue.

Posted By 183eej on 29 Oct 2010 08:56 AM
A soil PH below 6 in the United States is rare.

Maybe that's true for Baja Oklahoma, but I don't believe it
applies to huge areas of the right coast covered in red oak
forests with plentiful rhododendron and mountain laurel.

I haven't checked in here in a while and I'm not in the bussiness. However my DX system is still going strong since 1994. No problems with the copper so far. There is so much copper in the soil around here there are green flakes in the rock. When my US Powers system was installed they did a soil ph test and said it is fine as is. No cathods needed. I have a horizontal coil in rocky soil. I have replaced one compressor 2 years ago and an A coil a year ago in the air handler. It is a conventional Trane air handler and I've never been happy with it's ability to carry off the condensate water made during air conditioning. I think that has alot to do with the A coil leak. I replaced the Desuperheater at the same time as the A coil with an updated unit while the system was depressureized. This one gives me great hot water even in the heating mode. Compared to the neighbors bills mine are nearly 1/2. Most of my neighbors have already replaced their entire conventional systems some time ago. Put me firmly in the DX corner. If I was building again tomorrow 1st thing on the list would be a new DX system!

Kinda funny the talk about DX fouling the ground water. Never heard that before. In this state there are several wells fouled with anti freeze by leaking water based systems that were installed by a dealer who didn't know what they were doing. It all goes back to who did the job of installation. US Powers went out of business a year after my sys was installed. The dealer that installed mine still has several systems they installed around the same time out there running fine. Another dealer that installed these same systems locally have given DX a bad name as most of their installations failed long ago. Sized and engineered wrong for the application among other problems.