Geothermal Loop in basement

[marco67]

I've been following some of the threads over on RC on this and the subject of using copper for the underground came up. I know the thought of copper anywhere near our systems is scary at best ....but do you think the trade off might be worth it...excellent heat exchange= shorter loop length =smaller pump.
Obviously the concern here would be a leak, but given a good quality tank side exchanger or a DIY thats built well, that risk would be minimal.
I'm not saying it's a good idea just maybe an idea to kick around ....what about life of copper buried?

 

[Greg Hiller]

>eggcrate with the poly tube "woven throughout"<

Hmmm...hadn't thought of that. I was planning originally on wrapping the 1/4" tubing around a big piece of 3" PVC. I evenually decided that was too complicated, and was just going to dump a bunch into my sump, or maybe in some of the IO bucket-style tank-return bubble arresters I use that have a lot of turbulent water motion in them.

>any ideas on life expectancy on that aluminum once buried?<

Don't really know. But have you ever seen a corroded aluminum can? I have the coils wired to zinc sacrificial anodes. In any case, the cost of the aluminum coils is not what I'm worried about, but the effort involved in digging them up would be a drag.

>I've been following some of the threads over on RC on this and the subject of using copper for the underground came up. I know the thought of copper anywhere near our systems is scary at best ....but do you think the trade off might be worth it...excellent heat exchange= shorter loop length =smaller pump. <

I considered it, but the aluminum coils are so cheap I think that's the way to go.

>Obviously the concern here would be a leak, but given a good quality tank side exchanger or a DIY thats built well, that risk would be minimal.<

Yup...it's a trade off. You need to decide if it's worth the risk. I think if you were using a tank side commercially available heat exchanger I'd be a lot less worried.

>I'm not saying it's a good idea just maybe an idea to kick around ....what about life of copper buried?<

Don't know how they would compare. Aluminum is a pretty inert metal. Copper turns green over time when exposed to air (reacts with oxygen), but it might do better buried?

 

[marco67]

I spoke with them today at aquatic the guy I talked to (nice guy, very helpful, I forget his name ) said he new of nobody with experience using them on the in ground side. Like you say it's not the cost of the exchanger but digging them, I'm at 8' along the side I plan on using. Replacing those would be unacceptable.
Tank side exchanger is still up in the air but again I would agree one of the nice titanium commercial units would make for a good nights sleep.

Have you sunk yours yet Greg?
Mines going in next week .....That is if I can make up my mind on what to use.
Right now I'm partial to the copper for a few reasons, immediate availability being one second is I can make use of the 100+ feet of trench I have available and not worry about heating up the soil.

 

[Yaktop]

summers coming. whats new? new suggestions? Skatzen, did you have success? Greg, aluminum exchanges still the deal?

 

[Greg Hiller]

I hope mine works when I fire it up again. I wasn't all that sucessful in blowing the water out of it before the winter. Hopefully nothing froze and cracked.

I'd like to hear how Marc's is doing.

 

[marco67]

I'd like to hear how Marc's is doing.

By the time I was running water in the new building they were'nt needed, and I never got around to doing any testing.

 

[skatezen]

I actually never ended up following through with my idea. I am thinking of another way to cool the water when needed through highly efficient evaporation. Something similar to a swap cooler for green houses but on a much smaller scale.