Can geothermal heat be stored in the earth?

[ga-hvac-tech]

This shows the install of the ground loop, shows grouting and back fill with neutral PH sand. http://www.youtube.com/watch?v=FC69Vc-mcaQ

This would slow down or stop the corrosive effects of the soil. I would still clean and coat the manifold braze connections.

In 85 I repiped my Grandparents house in Jacksonville FL. Did it under a Great-Uncles plumbing license. I used K from the meter to the Main shut-off at the house. Within eight years it had been replaced. I went down deeper than the original, so it didn't freeze. So this is a universal problem.

From watching the video... it would appear the CO is not totally in direct contact with the ground... rather the plasticized grout. This changes the issue of corrosion IMO.

THX for posting the video!

[kaleun]

Where do we get copper? The ground? If earth destroys copper, then why do we have copper after 4 billion years?

The copper fields have a LIFETIME warranty on them.

Not really. the copper you dig up in a mine is corroded copper (copper-oxide). Same as iron ore is not iron, but an iron oxide (=rust)

Only noble metals (like gold) appear in pure form since they don't corrode (at least not with just oxygen). therefore all geothermal systems use some plastic piping. If you don't trust plastic for 4 billion years, you could use schedule 80 gold as well... if you can afford it

[Gross]

Not really. the copper you dig up in a mine is corroded copper (copper-oxide). Same as iron ore is not iron, but an iron oxide (=rust)

Only noble metals (like gold) appear in pure form since they don't corrode (at least not with just oxygen). therefore all geothermal systems use some plastic piping. If you don't trust plastic for 4 billion years, you could use schedule 80 gold as well... if you can afford it

Copperoxide acts as a barrier and doesnt allow further oxidation unlike iron oxide....again...thats why we are able to mine pure copper. (well we were able to before we got most of it lol)

[kaleun]

I think I would stick with the water loop... Water (or water/glycol mix) in some kind of plastic or vinyl/plastic or special tubing... probably would last a lot longer than CO directly in contact with the earth.

Someone correct me if I am wrong: A WF system installed by a special contractor (with the proper WF certs) can have a 50 (yes fifty) year warranty on the horiz loop??? That in itself would be worth a lot of the high cost of the install.

Also... I heard WF may be bringing out an inverter drive compressor Geo system sometime in 2012... anyone know anything more about this? Reason I ask is I may be looking at a GEO system in 2014.

I never would use any metal piping int he ground, always some type of plastic. I don't think i know of any copper pipe geo system. All use some HDPE or other product specifically made for glycol/earth.

The 50 year warranty is only good if the contractor stays in business that long chose the right contractor and the right design and material and you don't need the warranty. I'm sure there are certain certifications in your area to find a good contractor.

Gross: I'm not a mining expert. But a copper deposit in the earth is not just a cubic mile or pure copper with just the edges corroded and pure copper inside. It is copper-oxide mixed with all type of "dirt". I don't know exact %, but iron ore has maybe 5% iron to be worthwhile being dug up, copper may be even less. Even gold deposits or diamonds have much dirt around them. the erath didn't specifically separate metals for us to just dig up. there are just areas with higher concentrations. Maybe copper in normal earth is 0.00001% and in a copper mine it is 3%. (don't quote me on the numbers, I'm just illustrating). I've seen the copper mine by SLC (the largest in the world) and didn't see any copper at all, it all just looks like dirt before being smeltered and elctrolytically concentrated.

[madhat]

I would think that a direct earth contact DX system would be cheaper to install, and more efficent. In 20 years the technology will have changed enough to warrant installing a totally new system. Even though I have an acre and quarter of yard, I really don't want a very large area dug up for the horizontal loops. I thinking next Fall installing a new system, my mortgage should be paid, off and I can use the rather large escrow to pay for it.

[kaleun]

I would think that a direct earth contact DX system would be cheaper to install, and more efficent. In 20 years the technology will have changed enough to warrant installing a totally new system. Even though I have an acre and quarter of yard, I really don't want a very large area dug up for the horizontal loops. I thinking next Fall installing a new system, my mortgage should be paid, off and I can use the rather large escrow to pay for it.

EPA/DNR won't allow refrigerant in the ground. and the geo-piping isn't made for such high pressure. And filling miles of pipe with refrigerant isn't cheap.

Never ever install a horizontal system.

[Gross]

EPA/DNR won't allow refrigerant in the ground. and the geo-piping isn't made for such high pressure. And filling miles of pipe with refrigerant isn't cheap.

Never ever install a horizontal system.

Ok well you're just plain wrong and uneducated on that. I suggest you research DX geothermal before makIng more assumptions.

[Gross]

I would think that a direct earth contact DX system would be cheaper to install, and more efficent. In 20 years the technology will have changed enough to warrant installing a totally new system. Even though I have an acre and quarter of yard, I really don't want a very large area dug up for the horizontal loops. I thinking next Fall installing a new system, my mortgage should be paid, off and I can use the rather large escrow to pay for it.

It does end up using less energy bc there are no pump packs to power and there is no third heat exchanger. Google: Direct exchange geothermal

[Some Dude]

Pretty sure the loop warranty is only on the loop materials

[jpsmith1cm]

EPA/DNR won't allow refrigerant in the ground. and the geo-piping isn't made for such high pressure. And filling miles of pipe with refrigerant isn't cheap.

Never ever install a horizontal system.

Could you elaborate on the highlighted part above, please?


I am looking into a geo system for my own home and a horizontal system is the way I've been leaning.

[Gross]

Could you elaborate on the highlighted part above, please?


I am looking into a geo system for my own home and a horizontal system is the way I've been leaning.

Horizontal systems are the least efficient water source hp's. The shallower you are in the ground, the more temperature swing you have AND the more likely the ground is to dry out.

[ga-hvac-tech]

Could you elaborate on the highlighted part above, please?


I am looking into a geo system for my own home and a horizontal system is the way I've been leaning.

JP...

I am looking at geo for my home also... will be a few years out.

I was talking to someone a week or so ago... they said something about the ground getting heat-soaked or cold soaked. What that means is; after years, the efficiency just goes down. I can understand this, makes good sense.

One thing I keep hearing: Do ALL the proper engineering for the loop before starting construction... and do NOT cut corners.

Any of the geo contractors know if wells get heat soaked?

JP... we might need to start a new thread in Pro to talk about geo details.

[Gross]

JP...


Any of the geo contractors know if wells get heat soaked?

sure do, not as fast, but sure do. how often depends on what youre drilling into.

Had 3 different complaints from customers we put water furnace's in this summer....said they would stop working...sure enough I go out there and they have water temps of almost 100 degrees...called water furnace and they said "thats normal when its really hot"

i dont sell water source any longer.

[ga-hvac-tech]

sure do, not as fast, but sure do. how often depends on what youre drilling into.

Had 3 different complaints from customers we put water furnace's in this summer....said they would stop working...sure enough I go out there and they have water temps of almost 100 degrees...called water furnace and they said "thats normal when its really hot"

i dont sell water source any longer.

So how does one work around this 'heat/cold soaking' issue? More loop?

Also; seems to me if we are transferring heat or cold to soil... it does not matter the medium to carry the heat... what matters is enough soil contact to effectively dissipate the heat/cold. If this is true (suggesting, not stating), then it seems irrelevant which medium is used to carry the heat... what does seem important is enough ground to absorb the heat applied.

Seems a stream or river would be the best place to transfer heat/cold.

[Gross]

So how does one work around this 'heat/cold soaking' issue? More loop?

Also; seems to me if we are transferring heat or cold to soil... it does not matter the medium to carry the heat... what matters is enough soil contact to effectively dissipate the heat/cold. If this is true (suggesting, not stating), then it seems irrelevant which medium is used to carry the heat... what does seem important is enough ground to absorb the heat applied.

Seems a stream or river would be the best place to transfer heat/cold.

thats why open loop systems are the most efficiently running water source geo thermal systems

[Gross]

now that being said, your spot on. if you have a large enough body of water close by, you can put you loops directly into it

[ga-hvac-tech]

thats why open loop systems are the most efficiently running water source geo thermal systems

I can understand what you say... yet how does one keep an open loop clean (stuff sucked up)?

How do closed loops work when placed in a flowing stream or lake or river?

BTW: THX for your input!

[Gross]

[QUOTE=ga-hvac-tech;11796102]

Also; seems to me if we are transferring heat or cold to soil... it does not matter the medium to carry the heat... what matters is enough soil contact to effectively dissipate the heat/cold. If this is true (suggesting, not stating), then it seems irrelevant which medium is used to carry the heat... what does seem important is enough ground to absorb the heat applied.

QUOTE]

Thats not completely true and here is why. water, or antifreeze, doesnt transfer heat rapidly. HDPE is an insulator (R-.6 or .8) so its not the best at getting rid of the heat in the first place...now when your ground temp raises, the heat transfer rate stays the same. as the ground warms, so does the water....since the heat goes from refrigerant to copper to plastic to water to plastic to earth, it imperative that you get the absolute best transfer each time. when the ground warms up it REALLY shows on your water temperatures.
DX on the otherhand only goes from refrigerant to copper to earth...and since copper is a conductor, not an insulator, it doesnt have to over come the heat sink that is the HDPE and the water.

Even if the earth was 90 degrees, a DX system would work fine....would you mind 90 degree liquid temps?

[Gross]

I can understand what you say... yet how does one keep an open loop clean (stuff sucked up)?

How do closed loops work when placed in a flowing stream or lake or river?

BTW: THX for your input!

same as any well...drill until its clean...

http://www.energysavers.gov/your_hom.../mytopic=12650
that shows you a basic idea of different kinds of water source geo's. Water you do for a field in a body of water is you coil up the hdpe, just like a horizontal field, push it out into the body of water and as you fill it with coolant, it becomes heavy and sinks...you can put weights on it as well.

[ga-hvac-tech]

[QUOTE=Gross;11796162]

Also; seems to me if we are transferring heat or cold to soil... it does not matter the medium to carry the heat... what matters is enough soil contact to effectively dissipate the heat/cold. If this is true (suggesting, not stating), then it seems irrelevant which medium is used to carry the heat... what does seem important is enough ground to absorb the heat applied.

QUOTE]

Thats not completely true and here is why. water, or antifreeze, doesnt transfer heat rapidly. HDPE is an insulator (R-.6 or .8) so its not the best at getting rid of the heat in the first place...now when your ground temp raises, the heat transfer rate stays the same. as the ground warms, so does the water....since the heat goes from refrigerant to copper to plastic to water to plastic to earth, it imperative that you get the absolute best transfer each time. when the ground warms up it REALLY shows on your water temperatures.
DX on the otherhand only goes from refrigerant to copper to earth...and since copper is a conductor, not an insulator, it doesnt have to over come the heat sink that is the HDPE and the water.

Even if the earth was 90 degrees, a DX system would work fine....would you mind 90 degree liquid temps?

So what you are saying is:

Since DX runs refrigerant through the loop... the temps are wider and as such X-fer works over a wider soil temp?