Basic energy flow question...

Mark Eatherton

It has been bantered about that energy flows from hot to cold, correct? ALWAYS...

ME

ChrisJ

It's always been said that energy flows from something with a lot of it, to something with less. Yes.

Are people actually arguing a proven fact?

Robert O'Brien

Isn't that the second law of thermodynamics? I

hot_rod

Mark Eatherton said:

It has been bantered about that energy flows from hot to cold, correct? ALWAYS...

ME

Along the lines of "energy cannot be created or destroyed"?

A simple laymen explanation at this link.

http://www.livescience.com/50941-second-law-thermodynamics.html

ChrisJ

hot rod said:

Mark Eatherton said:

It has been bantered about that energy flows from hot to cold, correct? ALWAYS...

ME

Along the lines of "energy cannot be created or destroyed"?

A simple laymen explanation at this link.

http://www.livescience.com/50941-second-law-thermodynamics.html

Which is why set backs must work. They lower heat loss and since we cannot destroy energy, you do not "waste energy reheating everything in the building".

Harvey Ramer

There are other arguments but they are beyond the realms of our current daily use.

Mark Eatherton

Over the years, I have heard more than one GSHP expert make the claim that the GHP systems are actually just recovering the free solar energy that falls on the face of the Earth.

For example, http://blogs.scientificamerican.com/solar-at-home/is-a-geothermal-heat-pump-right-for-you/

If the Earth's molten core is 10,800 degrees F, and the surface is obviously much cooler than that, then common sense would tell me that the energy being recovered from the buried pipe in vertical bore holes is coming from the core of the Earth, and not the Earth surface.

To their credit, they do state that in shallow app's the energy is coming from the Sun, but they don't make the distinct difference between VBH's and horizontal fields, which I think is misleading.

Just food for thought....

Thanks for chiming in.

ME

SWEI

Mark Eatherton said:

If the Earth's molten core is 10,800 degrees F, and the surface is obviously much cooler than that, then common sense would tell me that the energy being recovered from the buried pipe in vertical bore holes is coming from the core of the Earth, and not the Earth surface.

If that VBH is deep enough, it is. True geothermal (as opposed to geo-exchange.)

ChrisJ

Dumb question but, without solar how would that core stay @ 10,800f?

Wouldn't it cool, or, is something else taking place?

BobC

As I understand it the cores heat comes from decaying thorium and to a lesser extent uranium.

Bob

Gordy

Bob has about 90% of it here is a link.
http://phys.org/news/2006-03-probing-earth-core.html

Mark I highly doubt you are questioning yourself.

Hot to Cold.
High pressure to low pressure.
Humid air to dry air.

mother nature seeks equilibrium.....You said it.

As far as the GSHP guys are concerned. In a transitional climate where seasons are prominent. Solar energy heating the ground has its limit on depth of penetration before seasons change, and wiinter sets in. With VBH I think you are far beyond solar influence.

Rich_49

The only heat that is from solar with VBH is what is left there during cooling season . The rest as stated is rising from below . Everywhere cannot have a vent .

JStar

ChrisJ said:

Dumb question but, without solar how would that core stay @ 10,800f?

Wouldn't it cool, or, is something else taking place?

Friction from when the Earth was forming. The inside of our planet is more of a hot swirling mess than your prom date.

Jamie Hall

Dear old Lord Kelvin was confused on why the core of the earth is hot, too, so don't feel too bad. He didn't know about radioactivity! The core heat is from radioactive decay. Since the surface of the earth is much cooler, that heat migrates to the surface (hot to cold!) and, below a few tens to hundreds of feet (hundreds in deep permafrost regions -- Siberia, for instance) the rock temperature is accounted for entirely by that heat transfer. At shallower depths, the relatively small variations from the local surface climate influence the temperature -- but the summer to winter swings only go down a few feet; perhaps tens of feet.

Warmer regions in the crust -- Iceland, for example, or Yellowstone -- are that way because of much better heat transfer from the core.

Jason_13

I have read that they have been monitoring the earth core temp since the late 1800's. The core temp is dropping about the same rate per decade since they have been monitoring it,

Mark Eatherton

I'd like to know exactly HOW they measure the cores temperature, seeings as how the temperature is hot enough to vaporize pretty much any temperature sensing devices that I am aware of... And just who the heck are "they"... THEY are everywhere... :-)

ME

Paul48

They are probably scientists Mark. If you apply the science of the whole topic you used for this post, you know how "they" could do it.
They would need the assistance of well-diggers though.

Jamie Hall

The measurement is indirect and inferred. No one's been there to put a thermometer in! But the solid to liquid transition temperatures of the possible materials are pretty well known, and the possible range of materials is pretty well known, and the depths to solid to liquid transitions are pretty well known -- and the rate of heat transfer to the surface is quite well known, actually.

But it's still an educated, though well educated, estimate...

Paul48

Sort of ..... like solving for btu/h, using the Universal Hydronic Formula,on a much larger scale. Simply monitoring annual change is easy, once you establish a baseline.