DIY geothermal heat pump

Hackney71 · 11-15-10, 11:48 AM

This thread looks a bit "dated" but I want in...
I am not an engineer, I am in sales for unrelated industry. My educational back ground, econ (all about efficiency). Here is my take... In my state (TN) the state eco Natzies have regulated out the DIY'er wanting to do Geothermal. I am limited to 20' depth from surface or Have to Notify State with intent to drill a "well" and need licenced driller to do it.
Direct Exchange, imho, is the most efficient means of "heat transfer" which is the heart of heat pump Idea...
So for me, needing about 2 ton unit. I have to calculate what Diameter of copper tube to use (for my system of coils to be buried) and how many I will need in what arraignment. (perameters for each hole being less that 20 from surface).
My idea is based on some law of thermodynamics that states heat only flows FROM material with more Heat TO material with less heat (without some outside force being applied). So whether I need to Heat or Cool, my directly buried coils will either be Absorbing heat from the ground OR the ground will be absorbing heat from the coils... Think more like a "Heat sync" on your CPU... I will gather some more info and return...

Daox · 11-15-10, 12:02 PM

Hello Hackney71. Welcome to EcoRenovator.

I split your post off to get its own attention. AC Hackers thread has gone off topic quite a few times.

pachai · 11-15-10, 01:52 PM

I am following this thread - read most of the past posts.
I tested my backyard, can easily "drill" a 6" hole 18" deep.
Not sure what is further down.

I am not sure how far this will go, as I am up North,
and have a full/time job, but I hope to enlist help
of the person who will dig my foundation -
maybe I can have him do some trenches and then put
some wells in the trenches. If I trench down 10' and
then drill 10', that's easier than a 20' well.

I parked a big old air conditioner on top of the hole,
just to discourage my son from exploring it.

Xringer · 11-15-10, 03:49 PM

Since you live in a Sun Belt state, why brother with the expense of pumping heat out
of the ground (or into it), when there is air all around you?
In the summer, you can pump the heat out of your house into the atmosphere,
and in wintertime, you can harvest solar and surface heated air with an ASHP..

It's MUCH cheaper to install a mini-split and it's almost as cheap to run as a GSHP.

We are loving our Sanyo..

http://ecorenovator.org/forum/geothe...l-project.html

This week, it's costing us about $1.75 a day to heat our home.
People on my street (heating with oil) are paying $3 a gallon and are
burning up at least 2 or 3 gallons a day..

Hackney71 · 11-15-10, 04:42 PM

Like here but DIY project : dub,dub,dub (dot) digtheheat(dot)com/geothermal/DX_geothermal.html

Xringer · 11-15-10, 05:07 PM

I've seen this stuff before.. But figured it was so expensive, very few people can afford it..

YouTube - EarthLinked GeoExchange Heat Pump System

Unless you can DIY..

Neat drill !!

Vlad · 11-16-10, 02:03 AM

Hackney71
Refrigeration systems are really complicated. To make it run efficient and in balance is real art. If you are going to use dx system do not try to calculate it yourself. It is extremely important to not oversize it or make it too small (I mean ground loop). The size of piping is very important because you can blow oil from compressor into loop and oil will stay there. Guess what is going to happen to your compressor? It will die. Another aspect (which made me stay away from this type of system) is corrosion. Without special anode system your loop will corrode and leak. This systems will only be possible to use when somebody start selling SS tubing for ground loop or cover copper with some polymer or ...

Vlad · 11-16-10, 02:15 AM

Quote:

Originally Posted by pachai

I am following this thread - read most of the past posts.
I tested my backyard, can easily "drill" a 6" hole 18" deep.
Not sure what is further down.

I am not sure how far this will go, as I am up North,
and have a full/time job, but I hope to enlist help
of the person who will dig my foundation -
maybe I can have him do some trenches and then put
some wells in the trenches. If I trench down 10' and
then drill 10', that's easier than a 20' well.

I parked a big old air conditioner on top of the hole,
just to discourage my son from exploring it.

As AC-hacker mentioned in his posts do not forget about safety. Working in 10' tranche is extremely dangerous. You can bury yourself and will not even enjoy you new energy efficient house

It is easier to drill then to dig.

AC_Hacker · 11-16-10, 02:13 PM

I received an email alerting me to this post.

When I followed the link the link in my email the post was not to be found, so I am re-creating it here. I don't know if the poster changed his mind, but it is a good post and deserves commenting on.

Here is the message that has just been posted:
***************
This thread looks a bit "dated" but I want in...
I am not an engineer, I am in sales for unrelated industry. My
educational back ground, econ (all about efficiency). Here is my
take... In my state (TN) the state eco Natzies have regulated out the
DIY'er wanting to do Geothermal. I am limited to 20' depth from
surface or Have to Notify State with intent to drill a "well" and
need licenced driller to do it.
Direct Exchange, imho, is the most efficient means of "heat transfer"
which is the heart of heat pump Idea...
So for me, needing about 2 ton unit. I have to calculate what
Diameter of copper tube to use (for my system of coils to be buried)
and how many I will need in what arraignment. (perameters for each
hole being less that 20 from surface).
My idea is based on some law of thermodynamics that states heat only
flows FROM material with more Heat TO material with less heat
(without some outside force being allied). So wether I need to Heat
or Cool, my directly buried coils will either be Absorbing heat from
the ground OR the ground will be absorbing heat from the coils...
Think more like a "Heat sync" on your CPU... I will gather some more
info and return...
***************

DX (direct expansion) is more efficient than water loop by about 15%. In other words you would need about 15% less loop fields with DX as you would with water loop. DX also has the advantage that protecting the loop field from freezing is not an issue.

Corrosion is the primary problem with DX. The result from corrosion of DX fields are serious as the lubricants involved in refrigeration will escape into the earth. This is similar to a leaking buried fuel oil tank... it's not good.

Depending on the heat load of your house and the size of your lot, twenty foot deep holes will work. The hole spacings (usually 12 to 15 feet centers minimum) still apply.

To get an idea of the loop field required, ask local GSHP installers and well diggers. If all else fails, study up on the matter, educate yourself.

Here is the best source of information I know of.

Currently, mini-split ASHPs are a pretty good option, as they are reasonably priced, utilize the latest technology and in the case of the very best of the lot, approach the efficiency of early GSHP systems. What the lifetime of a mini-split ASHP is, can't be stated yet as they are so new. I'm using one now, while my GSHP project is still on-going. I wonder about longevity of my mini-split every day... so far so good. Lifespans of GSHPs tend to be in the decades, as the compressor and control circuitry is protected from weather.

Regarding payback time (AKA: break-even) of commercially installed systems, ASHP win out over GSHP every time.

Regarding efficiency, GSHP win out over ASHP every time.

Regarding homemade GSHP systems, the results are not in yet. Nobody else is working on this approach, this is what makes this dialog so important. This is the reason that this thread has attracted 63,838 hits... no one else has done it.

But my reckoning is that if the price of a DIY install can be reduced from $24,000 (or more) down to $4,000 (or less) then we have a real game changer.

In that case, both the pay-back and the longterm costs favor GSHPs.

Regards,

-AC_Hacker

pick1e · 11-17-10, 07:38 PM

Sorry wrong thread! Please delete.

11-15-10, 11:48 AM	#1
Hackney71 Lurking Renovator Join Date: Nov 2010 Location: Tennessee Posts: 8 Thanks: 1 Thanked 0 Times in 0 Posts	DIY geothermal heat pump This thread looks a bit "dated" but I want in... I am not an engineer, I am in sales for unrelated industry. My educational back ground, econ (all about efficiency). Here is my take... In my state (TN) the state eco Natzies have regulated out the DIY'er wanting to do Geothermal. I am limited to 20' depth from surface or Have to Notify State with intent to drill a "well" and need licenced driller to do it. Direct Exchange, imho, is the most efficient means of "heat transfer" which is the heart of heat pump Idea... So for me, needing about 2 ton unit. I have to calculate what Diameter of copper tube to use (for my system of coils to be buried) and how many I will need in what arraignment. (perameters for each hole being less that 20 from surface). My idea is based on some law of thermodynamics that states heat only flows FROM material with more Heat TO material with less heat (without some outside force being applied). So whether I need to Heat or Cool, my directly buried coils will either be Absorbing heat from the ground OR the ground will be absorbing heat from the coils... Think more like a "Heat sync" on your CPU... I will gather some more info and return... Last edited by Hackney71; 11-15-10 at 11:51 AM..

11-15-10, 12:02 PM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Hello Hackney71. Welcome to EcoRenovator. I split your post off to get its own attention. AC Hackers thread has gone off topic quite a few times. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

11-15-10, 03:49 PM	#4
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	GSHP vs ASHP Since you live in a Sun Belt state, why brother with the expense of pumping heat out of the ground (or into it), when there is air all around you? In the summer, you can pump the heat out of your house into the atmosphere, and in wintertime, you can harvest solar and surface heated air with an ASHP.. It's MUCH cheaper to install a mini-split and it's almost as cheap to run as a GSHP. We are loving our Sanyo.. http://ecorenovator.org/forum/geothe...l-project.html This week, it's costing us about $1.75 a day to heat our home. People on my street (heating with oil) are paying $3 a gallon and are burning up at least 2 or 3 gallons a day..

11-16-10, 02:03 AM	#7
Vlad Apprentice EcoRenovator Join Date: Aug 2010 Location: Windsor ON Canada Posts: 229 Thanks: 4 Thanked 30 Times in 22 Posts	DX Systems ... and cons Hackney71 Refrigeration systems are really complicated. To make it run efficient and in balance is real art. If you are going to use dx system do not try to calculate it yourself. It is extremely important to not oversize it or make it too small (I mean ground loop). The size of piping is very important because you can blow oil from compressor into loop and oil will stay there. Guess what is going to happen to your compressor? It will die. Another aspect (which made me stay away from this type of system) is corrosion. Without special anode system your loop will corrode and leak. This systems will only be possible to use when somebody start selling SS tubing for ground loop or cover copper with some polymer or ... Last edited by Vlad; 11-16-10 at 01:57 PM..

11-16-10, 02:13 PM	#9
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Dissappeared Post... I received an email alerting me to this post. When I followed the link the link in my email the post was not to be found, so I am re-creating it here. I don't know if the poster changed his mind, but it is a good post and deserves commenting on. Here is the message that has just been posted: ************* This thread looks a bit "dated" but I want in... I am not an engineer, I am in sales for unrelated industry. My educational back ground, econ (all about efficiency). Here is my take... In my state (TN) the state eco Natzies have regulated out the DIY'er wanting to do Geothermal. I am limited to 20' depth from surface or Have to Notify State with intent to drill a "well" and need licenced driller to do it. Direct Exchange, imho, is the most efficient means of "heat transfer" which is the heart of heat pump Idea... So for me, needing about 2 ton unit. I have to calculate what Diameter of copper tube to use (for my system of coils to be buried) and how many I will need in what arraignment. (perameters for each hole being less that 20 from surface). My idea is based on some law of thermodynamics that states heat only flows FROM material with more Heat TO material with less heat (without some outside force being allied). So wether I need to Heat or Cool, my directly buried coils will either be Absorbing heat from the ground OR the ground will be absorbing heat from the coils... Think more like a "Heat sync" on your CPU... I will gather some more info and return... ************* DX (direct expansion) is more efficient than water loop by about 15%. In other words you would need about 15% less loop fields with DX as you would with water loop. DX also has the advantage that protecting the loop field from freezing is not an issue. Corrosion is the primary problem with DX. The result from corrosion of DX fields are serious as the lubricants involved in refrigeration will escape into the earth. This is similar to a leaking buried fuel oil tank... it's not good. Depending on the heat load of your house and the size of your lot, twenty foot deep holes will work. The hole spacings (usually 12 to 15 feet centers minimum) still apply. To get an idea of the loop field required, ask local GSHP installers and well diggers. If all else fails, study up on the matter, educate yourself. Here is the best source of information I know of. Currently, mini-split ASHPs are a pretty good option, as they are reasonably priced, utilize the latest technology and in the case of the very best of the lot, approach the efficiency of early GSHP systems. What the lifetime of a mini-split ASHP is, can't be stated yet as they are so new. I'm using one now, while my GSHP project is still on-going. I wonder about longevity of my mini-split every day... so far so good. Lifespans of GSHPs tend to be in the decades, as the compressor and control circuitry is protected from weather. Regarding payback time (AKA: break-even) of commercially installed systems, ASHP win out over GSHP every time. Regarding efficiency, GSHP win out over ASHP every time. Regarding homemade GSHP systems, the results are not in yet. Nobody else is working on this approach, this is what makes this dialog so important. This is the reason that this thread has attracted 63,838 hits... no one else has done it. But my reckoning is that if the price of a DIY install can be reduced from $24,000 (or more) down to $4,000 (or less) then we have a real game changer. In that case, both the pay-back and the longterm costs favor GSHPs. Regards, -AC_Hacker Last edited by AC_Hacker; 11-16-10 at 05:03 PM.. Reason: grammar

11-15-10, 01:52 PM	#3
pachai Renovator-in-planning Join Date: Oct 2010 Location: Northern NJ Posts: 85 Thanks: 6 Thanked 0 Times in 0 Posts	I am following this thread - read most of the past posts. I tested my backyard, can easily "drill" a 6" hole 18" deep. Not sure what is further down. I am not sure how far this will go, as I am up North, and have a full/time job, but I hope to enlist help of the person who will dig my foundation - maybe I can have him do some trenches and then put some wells in the trenches. If I trench down 10' and then drill 10', that's easier than a 20' well. I parked a big old air conditioner on top of the hole, just to discourage my son from exploring it.

11-15-10, 04:42 PM	#5
Hackney71 Lurking Renovator Join Date: Nov 2010 Location: Tennessee Posts: 8 Thanks: 1 Thanked 0 Times in 0 Posts	Like here but DIY project : dub,dub,dub (dot) digtheheat(dot)com/geothermal/DX_geothermal.html

11-17-10, 07:38 PM	#10
pick1e Helper EcoRenovator Join Date: Nov 2010 Location: Michigan, USA Posts: 57 Thanks: 0 Thanked 0 Times in 0 Posts	Sorry wrong thread! Please delete. Last edited by pick1e; 11-17-10 at 07:56 PM.. Reason: I am disoriented.