The Homemade Heat Pump Manifesto

[AC_Hacker]

Originally Posted by braebyrn

So if you had access to a lathe, what would the dimensions be of the sockets? I thought about making my own and having them coated, but didn't know what the dimensions would be before the coating?

Maybe if you could get some pipe and the socket, or the right-angle pieces that the tool would use, you could get the dimesnions from the plastic parts.

Originally Posted by braebyrn

Are most folks using 1" pipe down the boreholes?

Can't speak for the others, but I used 3/4"

Originally Posted by braebyrn

Can't wait for the ideas on the training video?

Well, I hope I haven't built it up too much...

Here's the link:

Caleffi - Webinar Archive

...go to the 6th or 8th webinar down, called "GEO Hydronics". There were three total, they've only posted the first 2.

I thought the first one was the best.

I think that the intended audience is experienced GSHP installers, and the real purpose of the webinar is to sell stuff that the company makes, but still there are ideas to be had.

Also, on this page:

Caleffi - idronics -

...there are a bunch of publications. The most recent one:

http://www.caleffi.us/en_US/caleffi/...onics_9_us.pdf

...is a pretty thorough book on GSHP principles, etc.

And from another source all together, here is an interesting manual:

http://www.mcquay.com/mcquaybiz/lite...al_021607b.pdf

Best Regards,

-AC_Hacker

[Geo NR Gee]

Very interesting and informative webinars. Thanks for the links. Today we moved the Hydra-Drill over about 10 feet after the first hole ended with the drill sinking in the muck and drilling a crooked hole.

Also, we secured the mast with tension wires to keep the drill from shaking so much when it hits rocks. That in itself made it much more stable. It went to 15 ft. and then hit a pocket of what must be small rock as it gets stuck there. I ended up breaking the sheer pin again and then the winch wire.

My next modification will be a electric winch to assist in the raising and lowering of the drill.

AC, I now realize how grueling it must of been drilling your boreholes!

[S-F]

It seems like AC_Hacker has gotten the HP part pretty well under control. Am I right? Now the big obstacle is the GS part. That's always the big issue with geothermal. I think that in order to really get this all working well someone is going to have to figure out how to DIY a down the hole hammer. I fear that it will take way too many 20' holes to get this all working on any kind of large scale. Can one just buy a down the hole hammer to go on the end of one of these shafts?

[AC_Hacker]

Originally Posted by braebyrn

AC, I now realize how grueling it must of been drilling your boreholes!

It really was a lot of work. I used several different methods. By the time I got to the last few holes, I really knew what I was doing, and it was much easier and faster.

Keep it up, don't get discouraged. There's a lot to learn about this stuff. You're at the very beginning.

You've never said how much space you have to dig... Do you have space to trench if it gets too rocky for your drill?

Originally Posted by S-F

It seems like AC_Hacker has gotten the HP part pretty well under control. Am I right?

Yeah, I feel pretty confidant that I can do the Heat Pump part OK, but there are still questions about controller, and a buffer tank, and the radiant floor (it all works together).

Originally Posted by S-F

Now the big obstacle is the GS part. That's always the big issue with geothermal.

You're right there, it is the big issue. Big in terms of cost if you're buying it and big in terms of labor if you're into DIY.

But just digging the hole or trench isn't the only issue.

There are some considerations I wasn't as aware of when I started, having to do with the total friction of a loop and the power that is required to pump water through the loop at a rate that will yield the heat required, and how to best manage and balance those considerations. I'll address these issues in a subsequent post, in considerable detail.

I'm running right into those things now. I had a hunch about it when I was digging the field, and allowed myself some options, so I'll be able to dig up some of the pipe (not too much, just some connection pipe) and make things better...

The problem is that I probably should have used larger diameter pipe (1" instead of 3/4"). This would have reduced fluid friction a lot. I also have my whole loop as one serial loop with a length of 720 feet. Which is a lot for 3/4" pipe. Added to that is all the angles in my whole loop (48) which also increases friction. Added to that is all the butt welds (I have over 100) which adds additional friction.

If I break the 720 foot loop into two loops, I should drop the friction by more than half, because I will have effectively doubled the cross-sectional area of my loop and in addition I will have reduced the fluid velocity by 50% which will have a very beneficial effect in reducing friction.

Originally Posted by S-F

I think that in order to really get this all working well someone is going to have to figure out how to DIY a down the hole hammer... Can one just buy a down the hole hammer to go on the end of one of these shafts?

A down the hole hammer would be good for breaking up rocks. Also a percussion drill (AKA: cable drill) works well also.

But you know, it's all very dependent on the soil formation. A rig like braebyrn is using is just fine for clay or sand and for smaller rocks. The big rocks can be a challenge, but if he can get through them, he may be able to achieve some good depth.

Vlad apparently built a really herky version of braebyrn's rig that was driven by a 5 HP electric motor, which has much more power than a 5HP gas engine, and Vlad had some serious tri-cone bits for rock. He was reporting depths of 50 feet, which he was able to do in a fairly short time, when last we heard from him. I believe he lives in the Vancouver, CA area and has similar soil conditions to braebyrn and myself.

There is an alluvial valley about 30 miles from here which would be a dream to drill into. From what I hear, it's pretty much clay & sand & smaller debris down to around 75 feet. I hear reports that there are areas in the American South East that are similar.

But I did think of some kind of DIY down the hole hammer when I was hitting rocks... I bought an impact tool from Harbor Freight and was amazed how well it went through my cement foundation, when I was doing plumbing. Harbor Freight also had a gloriously herky pneumatic demolition tool and I was eyeing that as a possibility... they also had a pneumatic tile removal tool. Something like that might have worked, too.

What I ended up doing was building a rock grabber that got me out of the rock problem.

But in these parts, the rocks aren't dispersed homogeneously throughout the ground, they're in layers left by ancient floods, And they're spread around in the layers, and there are empty spaces with no rocks through the layers too.

It's a little like fishing, only the rocks are like the fish you really don't want to catch.

Originally Posted by S-F

I fear that it will take way too many 20' holes to get this all working on any kind of large scale.

I think the secret is to reduce the heat loss of your house to the point that working on a large scale is not necessary. That has been in my thinking with regard to this project from the very beginning... insulate, insulate, insulate.

Best Regards,

-AC_Hacker

[Geo NR Gee]

Originally Posted by AC_Hacker

You've never said how much space you have to dig... Do you have space to trench if it gets too rocky for your drill?

There is less than 50 x 30 in the backyard that is usable space. It is the lawn area as the rest is landscaped and has sprinklers. Trenching would only get me about a 40 x 20 patch. That is somewhat the area that the boreholes are (maybe) going.

If I had a video camera that could go in the borehole to see the material, it maybe helpful. The drill stem/bit gets stuck and seems to only get freed when it is turning and being pulled up at the same time. It feels like small rocks are caving in on it as the drill goes thru that layer like you talk about.

I wonder if the mud mixture for sealing the walls is not sufficient? Its gotta be the loose material caving in? When I broke the sheer pin and turned off the unit, the water disappeared down the hole in a matter of a minute at the 15 foot mark. It didn't do that at 10 feet or 5 feet, but at 15. It took about 20 gallons or more to fill it back up.

Tomorrow the shop vac like you used is going to suck the rest of the water out and hopefully I can see what is making the drill bounce. Harbor Frieght has a huge sale going on this weekend, so maybe an electric winch will help?

Maybe I can drop one of my security video cameras into the hole, yeah thats it. Not sure if it can focus at that close of a distance?

[AC_Hacker]

Originally Posted by braebyrn

There is less than 50 x 30 in the backyard that is usable space. It is the lawn area as the rest is landscaped and has sprinklers. Trenching would only get me about a 40 x 20 patch. That is somewhat the area that the boreholes are (maybe) going.

That's pretty small for trenching... I suspect that it doesn't give you very much room to maneuver a backhoe. If there are any readers that have experience with earth moving equipment, now is the time to speak up. I've not used that kind of equipment, so I can't speak from experience.

But if maneuvering equipment was not an issue, and you trenched to the edges of your space, and did two 40 foot trenches with slinkys, I think you could get about a Ton (12,000 BTU/hr) out of that area. That could be helpful over the course of a winter.

If you got a backhoe with a narrow bucket and dug deep trenches, like maybe 8 feet deep, and buried your slinkys vertically you might get even more, like maybe 1.5 Ton...

If you're able to do boreholes down to 200' (as you might now suspect, that's a lot of drilling) that would be about a Ton per hole. If you separated those holes by 20 feet and put one at each corner and one midway down the edge of the longer dimension, that would give you six Tons.

...six Tons would be way more than you need... but if you could get down 100 feet, you'd get something less than 3 Tons which is about your target, right? and you'd get 20 feet of separation, which for our climate is pretty good.

If you did a layout like this:

You'd reduce your separation to about 14 feet which is getting a bit close, even for our mild climate, and your soil temperature would probably decline more noticeably toward the end of the heating season, but you might be able to strangle maybe 2.5 Tons out of it at 75 feet depth.

Originally Posted by braebyrn

If I had a video camera that could go in the borehole to see the material, it maybe helpful. The drill stem/bit gets stuck and seems to only get freed when it is turning and being pulled up at the same time. It feels like small rocks are caving in on it as the drill goes thru that layer like you talk about.

I did the video camera thing also, it was very informative. I used a cheap webcam I got from the thrift store, and an extension USB cable. I carried my laptop out into the back yard and lowered the webcam down (I had to use some duct-tape to force the webcam to look sideways). I even did a video of the thing. Sorry I never posted it... it's gotten away from me now. But I could see the various layer, etc. The most interesting thing was that I was drilling down into the abandoned cesspool in the back yard... what a surprise! Its contents had turned to compost decades and decades ago. But you could see all of the different layers and the gravel and the sand and the clay. Yeah, I was loosing a lot of water into the cesspool. I never could fill up the hole with water or mud. I had to fill it in with dirt and move to another spot.

BTW, did you inquire with the gas and water and sewer to see if any kind of significant utility is traversing your lot? it could be pretty important. I think there is some kind of a "before you dig" number you can call.

Originally Posted by braebyrn

I wonder if the mud mixture for sealing the walls is not sufficient? Its gotta be the loose material caving in? When I broke the sheer pin and turned off the unit, the water disappeared down the hole in a matter of a minute at the 15 foot mark. It didn't do that at 10 feet or 5 feet, but at 15. It took about 20 gallons or more to fill it back up.

I don't know what kind of mud you are using. I bought some stuff called "Quik-Gel" made by Halliburton that was recommended to me by my supplier, as the kind of mud that the people who are doing geothermal are using. There was a mix recipe on the side of the bag that I went by. I think you can vary the mix concentration for various conditions. I didn't have such a good setup, my mudpump was the really weak link, it kept plugging up and I got so frustrated that I went with the shop vac. You have a much better setup than I had, and you have a better shot at getting it to work for you. I have heard tales of people in your neck of the woods getting down 80 feet with a rig just like you have.

But the situation that you have described is not uncommon. it is called "loss of drilling fluid". I have heard of people filling up the leaking part of the hole with quick cement and drilling through that, as if it were a casing... Sounded extreme to me.

The mud running out of the hole can mean that you have hit a gravely, water-bearing layer... which can be good, especially if there is a lot of water migrating through it. I was hitting something like that when I hit the hardpan. One problem with using mud for drilling is that it obscures the cuttings coming up out of the hole. When I was working with the shop vac, it was just perfect, I could see exactly what was happening down the hole (I duct-taped LED flashlights to my vacuum extension pole and I could even tell when the dampness of the sand was changing... try to do that when you're drilling with mud!

Originally Posted by braebyrn

Tomorrow the shop vac like you used is going to suck the rest of the water out and hopefully I can see what is making the drill bounce. Harbor Frieght has a huge sale going on this weekend, so maybe an electric winch will help?

The shop vac I was using was a Rigid, the biggest one they made. I lucked out and got it at a thrift store for $15. I got a flexible extention hose and the tubes I was using were 2" diameter ABS plastic. I found some screw together collars and I made up a set of various lengths and could mix & match as I went deeper. Much, much slower than mud drilling. But I think that doing one bore-hole with a vacuum or something similar is very useful, because then you know what your soil is like, cause the other holes will be very similar.

Originally Posted by braebyrn

Maybe I can drop one of my security video cameras into the hole, yeah thats it. Not sure if it can focus at that close of a distance?

Make a video and post it to youtube, it will be a smash hit!

Regards,

-AC_Hacker

[Geo NR Gee]

Access to the backyard is limited. There is however standard 7' high pass thru garage doors to the backyard. Boreholes at this point seem to be the best choice if the drilling can go deep enough.

[AC_Hacker]

Originally Posted by braebyrn

Boreholes at this point seem to be the best choice if the drilling can go deep enough.

Here is Army Field Manual 5_484 on well drilling.

There might be useful information in there for you.

Here's a website that focuses on non-machine powered well drilling. May be good for inspiration.

There are a lot of wells being drilled by christian missionaries, that may be a good source of info for you...

Here's a manual from Lifewater International... pretty good info.

I would suggest also scouring Youtube for videos on water well drilling. A video might only have one small segment that helps you get beyond an impasse, if it does, it's a good video... post it here.

BTW, here is a Ukranian well-drilling video complete with music by Zamfir! I thought you'd get a kick out of it.

http://www.youtube.com/watch?v=dB_Ltxb9xK0

I might not have said anything about a power winch, but I got one when I was drilling, and it made drilling much safer and more effective.

Deeper is always better, but as I mentioned before, you might hit an aquifer with a goodly amount of water migrating through it. That might work for you.

One thing I didn't do that I thought of doing was to make a double loop in the wet part of the hole:

...under ordinary circumstances, a double loop would only give you a 5% increase or so, but I think that if you were in an aquifer, it would be much higher. Also, I was making pretty big holes so the double loop would have been pretty easy. In your situation, with smaller diameter holes it might not be possible.

Take lots of pictures, if you come across useful videos and other information, post them to this thread for other folks that come after you... there are people who can learn from your efforts.

We're cheering you on...

Best regards,

-AC_Hacker

[Geo NR Gee]

We used a camera today to show what the borehole looks like. No drilling today. Mostly installing the 2000 lb. electric winch and wiring. Here is the video......

Borehole view for Geothermal Ground Loop Test 1 - YouTube

The video is actually over at 2:40. I don't have an editing program that works on .AVI format.

The video came out wide screen on youtube, and I don't know how to fix that. It makes the hole look bigger than it is.

I taped a wide angle lense to the camera to get it a little more close up. The borehole is only about 5 inches across so the rocks can look rather large. There are some that do stick out when you look down the hole. Now I know why the drilling machine bounces. It hits one of the larger rocks and moves over until it passes. Then it goes back to the center again. Now sure how that will work if you put a casing down. Good thing I am only putting the geo pipes down and then filling it up with grout.

[AC_Hacker]

Originally Posted by braebyrn

We used a camera today to show what the borehole looks like.

The video is actually over at 2:40. I don't have an editing program that works on .AVI format.

The video came out wide screen on youtube, and I don't know how to fix that. It makes the hole look bigger than it is.

There's a Free video editing program called VirtualDub that can fix both of these things. You'll need to locate a tutorial somewhere. I've been using it for years, wouldn't be without it.

Originally Posted by braebyrn

The borehole is only about 5 inches across so the rocks can look rather large. There are some that do stick out when you look down the hole. Now I know why the drilling machine bounces. It hits one of the larger rocks and moves over until it passes. Then it goes back to the center again. Now sure how that will work if you put a casing down. Good thing I am only putting the geo pipes down and then filling it up with grout.

Looks good... nothing fatal.

Whenever you do get around to the grouting part, you'll want to keep in mind that the tubing will be much lighter than the grout, and might want to float up out of the hole. I have seen people using weights (like window sash weights) tied to the bottom of the loops to pull them down. Might help to fill them with water too.

I ended up just refilling the holes with the dirt that came out. I used lots of water with the dirt to promote settling. I was having the problem with the loops wanting to come up out of the hole, but I found that if I threw inseveral shovel-fulls of dirt first before any water, the loops stayed where they belonged.

Keep going, you're off to a great start.

-AC_Hacker