Thernal transfer grout or just concrete for thermal tranfer

[ecomodded]

In some cases they use a high thermal transfer grout to surround geothermal ground lines, I am thinking this might be a superior product to use for Hydronic heating or cooling.

Since they go to the trouble to use a high thermal grout to surround geothermal lines would it be worth it to use the grout to surround the lines in the floor heating circuit or a refrigeration cooling circuit ?

I could use opinions on if concrete will be just as good to use as a thermal grout for cooling in my case but I think it would apply equally to heating.

I am making a line imbedded mini refrigeration unit and want it to function well.

I want to hear concrete would be just as good as its easier to get but I would seek out and get the thermal grout if its deemed worthy.

educated guesses or opinions would be helpful as I am winging it.

[ecomodded]

I looked into thermal grout more thoroughly , its basically just a high silica sand grout with concrete and plasticizers in it.

So i looked at home hardwares advertising for grout , they have 25lb Sanded Floor Grout.


here is the description of home hardware's standard grout:

A Polymer modified, blend of portland cement, specially graded and washed silica sand and organic pigments
Requiring only water for the mix, this rapid curing product will yield, when cured, a hard, dense, non- shrinking, uniform colour joint that produces high compressive strength with improved flexibility and freeze-thaw stability
This non-toxic, non-dusting, iron-free grout is resistant to bacteria, fungus, oils and alkalis

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Which is close enough to a thermal grout as it is made from the same fine grade silica sand.

I also found out that they use thermal grout for hydronic radiant heating as well as for filling around

geothermal lines to increase thermal transfer of the bore hole.

In short its a cheap readily available product that will increase the transfer rates of hot or cold.

I am going to use it with the edition of added concrete powder to increase its structural strength.

[Mikesolar]

So, what do you think the increase in thermal conductivity of your mix would be over a normal sand mix or concrete and what would be the real benefit?

My point is.....there is no real need to get a higher conductivity out of a concrete slab as the dT over the loop is usually appropriate for length of tubing and size of room. Having a higher heat draw out of the tube would only mean, IMO, that a typical 250' loop length would be dropped to (for example) 200'. What would the implication of that for your system? What size area are you trying to heat?

[ecomodded]

Originally Posted by Mikesolar

So, what do you think the increase in thermal conductivity of your mix would be over a normal sand mix or concrete and what would be the real benefit?

My point is.....there is no real need to get a higher conductivity out of a concrete slab as the dT over the loop is usually appropriate for length of tubing and size of room. Having a higher heat draw out of the tube would only mean, IMO, that a typical 250' loop length would be dropped to (for example) 200'. What would the implication of that for your system? What size area are you trying to heat?

Silica has a very high thermal transfer rate much more then common concrete does

I will post the thermal values later when I look threw my bookmarks , if memory serves me correctly its 3x more effective at thermal transfer as compared to concrete.

PDF file on benefits of thermal grout

GeoPro_Importance_of_Grout_TC.pdf

[AC_Hacker]

Originally Posted by Mikesolar

....there is no real need to get a higher conductivity out of a concrete slab as the dT over the loop is usually appropriate for length of tubing and size of room. Having a higher heat draw out of the tube would only mean, IMO, that a typical 250' loop length would be dropped to (for example) 200'...

I have seen this kind of reasoning before, here on EcoRenovator.

It is correct if your objective is to build the minimum heat-transfer structure.

However, if it is your intent to build a system with maximum efficiency, then another kind of reasoning is called for...

-AC

[ecomodded]

I am making a DIY fish tank cooler from a water jug cooler , for the thermal mass rather then water It will employ cement or common grout with its fine grade silica sand.

the stainless chiller bucket will not be used , just the copper refrigerant tubing that spirals around it.

Its that tubing that will be embedded in concrete and wrapped in layers of thin black poly tubing with concrete or grout in between to insure 100% contact and thermal transfer from one coil to the next.

After its wrapped with 70 feet of tubing ,inside and outside of the copper spiral
I will encase in a few inches of concrete to act as the thermal storage.
then it will be encased in about 6" of ' Great Stuff ' spray insulation.

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to circulate the tank water threw the tubing I will us my Aqua Lifter dosing pump ,which is normally used in conjunction with a float switch for automatic top ups of the main fish tank from a lower water tank.

The Aqua dosing pump is rated at 3GPH , it is going to be controlled by a eBay temperature controller relay with on / off temp settings.

The stock water cooler comes with full control over temperature settings so I have its built temp controller to adjust the chiller itself.

[Mikesolar]

Interesting. I assume the copper tube will not be in direct contact with the cement. I couldn't tell exactly from your post if it was. I don't know how many feet of tubing there will be but you may not get the 3GPH (H not M?) from a pump that is designed for a lower head loss. Something to check.

[ecomodded]

Originally Posted by Mikesolar

Interesting. I assume the copper tube will not be in direct contact with the cement. I couldn't tell exactly from your post if it was. I don't know how many feet of tubing there will be but you may not get the 3GPH (H not M?) from a pump that is designed for a lower head loss. Something to check.

Ii thought more on your concern with pump strength and decided to use less line to lighting the work load, instead of 70ft of poly I am going to use 20 ft. of 1/4" primmer covered copper tubing.


The chiller will be raised up to the tanks water level to use the siphoning effect instead of pushing all the water , the pump will use its vacuum to raise the water 10 inches to start the siphon off.

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Turns out the refrigerant coil was soldered together in a few places , which is why I could not unravel it.

I cut the stainless chiller bucket apart and was then able to pull the coil free and remove the bucket.

I am going to add a $14 eBay panel mount kWh / watt meter so I can keep tabs on its economy.

That's about it , I will start a separate thread with photos of its construction and test data.

[AC_Hacker]

Originally Posted by ecomodded

Ii thought more on your concern with pump strength and decided to use less line to lighting the work load, instead of 70ft of poly I am going to use 20 ft. of 1/4" primmer covered copper tubing...

It might be useful for you to investigate the physics of fluid flow.

You will learn much.

-AC

[ecomodded]

Originally Posted by AC_Hacker

It might be useful for you to investigate the physics of fluid flow.

You will learn much.

-AC

I think a siphon is a easy concept what could possible be the issue with it ?