DIY well drilling / trench digging for GSHP

[AC_Hacker]

Duplicate post please nuke...

-AC

[Geo NR Gee]

How important is it to monitor the flow/temp. of each borehole? I like the idea of the manifold in one location and the ability to isolate a problem section. Also it would be cheaper to run more hdpe pipe instead of digging up the yard.

[AC_Hacker]

Originally Posted by Geo NR Gee

How important is it to monitor the flow/temp. of each borehole?

I wish I had years of loop field experience, so what I say is not guided by experience... but loop fields should be pretty reliable, especially if the proper materials and techniques are used, and everything is tested... so, it seems to me that there is little risk and not much need for isolating each hole on that account. However, a single-well failure is possible (but unlikely), and being able to isolate that well would be very handy, indeed.

Being able to isolate each bore hole would be highly useful for purging, and a smaller pump could be used in that case.

Originally Posted by Geo NR Gee

I like the idea of the manifold in one location and the ability to isolate a problem section. Also it would be cheaper to run more hdpe pipe instead of digging up the yard.

Good points...

As I understand it, most GSHPs were set up with a welded manifold box outside. I think the manifold/home-run idea is pretty new in the GSHP world, but it's common in the radiant floor world.

-AC

[Vlad]

Originally Posted by AC_Hacker

Vlad,


When you purge your system, you'll need a minimum purging velocity. As I recall it is something like 2 linear feet per second. So keep some pump that is able to deliver sufficient volume to give you 2 ft/min minimum in your pipes.



-AC_Hacker

So is it 2ft /second or 2ft /minute?

I found it: http://www.hydro-temp.com/help/drawi...nual%208.4.pdf

It is 2ft/sec

First I was thinking 2ft/sec is just too much flow I don't need that much. But after I paid more attention and found "purge" word in your post.

I will use my propane powered gas water/mud pump for purging. It will create the hurricane in the loop

[Vlad]

Originally Posted by AC_Hacker

Vlad,

Excellent write-up.

Congratulations on the well-drilling goal, and good luck on joining up your loop field. You have some pretty good tools, so it should be pretty straight forward.

What does your hole pattern look like, and how do you intend to join up the wells? I assume you will use some kind of series/parallel setup.
-AC_Hacker

All loop holes are spaced 12 feet apart. I know it must be 15 but I don't want to buy my neighbor back yard The whole pattern is 3 holes x 5 holes.

X====X====X==


X====X====X==


X====X====X==


X====X====X==


X====X====X==

3 holes in series and 5 parallel loops. 5 parallel loops are in return reverse pattern.

Each loop is 3/4" IPS HDPE DR 11 pipe. The loop length will be approximately 400' each (3 holes section)

Headers are 1 1/4 IPS HDPE DR11 pipe

All pipes are socket welded.

Originally Posted by AC_Hacker

HERE is a trade publication issue that addresses GSHP loop issues. Their intention is to sell you stuff, but you may find something that is actually DIY-useful. As I recall, they recommend a 'home run' setup, with each well running back to a manifold which has separate flow gauges and valves, just like your radiant floor manifold. It makes purging simpler, and balancing easier, but the real advantage (for them) is that they get to sell you more the hardware. You might be able to dream up a hybrid setup that would give you most of the advantages of easy purging and loop balancing with less hardware.
-AC_Hacker

I don't think that you need manifold system. Headers, yes.

HDPE pipe is very robust. I can't even imagine what can damage it, especially when it all buried in cement grout.

If you have all loops the same length and all connected in return reverse pattern they will all have the same water flow and temperature. If you have 15 holes it is almost impossible to bring all pipes into one point and have all loops the same length.

The same pattern is used for ice rinks and there is very critical to have the same temperature.

You do need manifold in your house because this is how you can set up different temperature in different parts of your house.

[Vlad]

Now I am thinking about loop capacity. My guess it is about 4 ton. But I might be wrong. Just too many variables to estimate loop capacity. If somebody have better idea please correct me.

Also I plan to use loop water for different units. At the beginning I was thinking about putting one large pump for outside loop. But now I am thinking about terminating 1 1/4" headers in some kind of manifolds. The manifolds will be in my crawlspace. From this manifolds (supply and return) I can direct water to units I need.

Units will be all different capacity. I think to put smaller pumps for each unit (may be just buy one size 3 speed pumps). Every unit will control its pump (compressor delay start, pump delay stop etc). Also I will need to add check valves or just get pumps with built-in check valve.

At this moment I think I will need:
1. 9k BTU unit for air heating/cooling(mostly heating). This unit will run most of the time.

2. 12K BTU unit AC only. It will be used occasionally for extra AC capacity.

3. Also I want to add unit for domestic water heating. My guess is 24K BTU. This unit will run 6-8 hours a day.

I think this arrangement is the easiest way to control loop flow and make pumping the most efficient.

What do you think about this ?????

[AC_Hacker]

V,

In Manifesto, I outlined a proceedure to test loop capacity.

This is same proceedure big guys use.

If more questions, write.

Sorry... bad connection, am on sailboat.

Best,

-AC

[chiphum]

Hey Guys, I have built a similiar drill rig to that of Vlad. First day went well, 1ft/hr through limestone now @ 11ft. 7mud / 4rock. Will post updates. Hydralic motor & gas trash pump.

[Vlad]

Originally Posted by chiphum

Hey Guys, I have built a similiar drill rig to that of Vlad. First day went well, 1ft/hr through limestone now @ 11ft. 7mud / 4rock. Will post updates. Hydralic motor & gas trash pump.

Can you please post more info? Power, water swivel, hydraulics, drill bit etc... and pictures

[Vlad]

My drilling was finished about 1.5 month ago but weather was holding me back. Last week I rented excavator to dig trenches. So now all my vertical loops connected together, pressure tested and I started burying process. Few more days and my ground loop will be done