01-04-15, 01:50 PM | #1711 |
Journeyman EcoRenovator
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Interesting.
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01-04-15, 08:07 PM | #1712 |
Apprentice EcoRenovator
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Location: PNW
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diy cable tool
Couple of notes on cable tool drilling.
1st try was 45 years ago for drinking water - simple capstan and 200# bit with manila rope. Got down about 10 ft and hit a basalt boulder - dead stop, bit just bounced - ended up HAND digging a 18 ft well that performed adequately for household water till the drought of 1987 - basically no rain from April till December. So had to go deeper, could just 'do it' then as already had water rights, etc. Early 1990s there were new law and permit fees for drilling in WA. Anyway, drilled down to 60 ft. Probably spent 500 hours of time building a tower, welding up walking beam on back of old Datsun truck, etc, etc. and drilling the well with an 800# bit. Some days, as when going thru a 3 ft dia basalt solid boulder (as evidenced by chips brought up) it was literally only inches per hour. At the end, hit blue clay later at 60 ft with 5 ft of balck sand over it, pumped 29 gpm all day in July and no slow down of flow, biggest pump I had. That all said, this last summer AT&T drilled a soil test hole 40 ft deep 100 ft from my well with a 3/4 million dollar rotary rig that only took them about an hour total !! - then filled it in immediately. They did go thru some 1 ft dia basalt boulders. Moral or story. DIY well drilling is fine to do once, just for the knowledge and experience, but at an effective $$ return vs pro job I 'made' less than 1/2 minimum wage for time spent. Would not do multiple wells - buy a backhoe and dig a lot of 15 ft deep trenches, then you have the backhoe to keep too. Or get a 'package deal' on multiple wells, half the hour cost of the driller for a single well is getting to and from the site. Moral of story |
01-04-15, 11:58 PM | #1713 | ||||
Supreme EcoRenovator
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I'm also sure that the rain will increase the heat extraction because of the increased thermal conductivity of water, especially as compared to dry earth. It helps to know that where I live, the earth is wet all winter long, so a heavy rain changes things from very wet to more very wet. We get an annual rainfall of about 36 inches per year, and it is focused on the winter months. The above chart illustrates the pattern of rainfall, and as you can see, our rainfall is substantially reduced in the summer, and occurs in great abundance in the winter. Also, on the above chart, notice what our winter temperatures look like, and compare that to a similar chart for Oakham, MA. You will see that our winters are milder than yours, even though we are on about the same latitude. The difference is the steady weather that blows in from the Pacific. Here, in the winter, if it is clear, it is generally cold. If it rains, it generally gets warmer. When liquid vapor condenses, it releases heat, no matter if the vapor is Freon, Propane, or water. This process is at the heart of all vapor-compression refrigeration machines, and likewise, the weather. Quote:
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* * * While we are on the subject of GSHPs and boreholes and drilling, I just came across a most excellent paper on determining the conductivity of a borehole by experimental testing. This method would be even more reliable than IGSHP tables. * * * Good luck! -AC_Hacker
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I'm not an HVAC technician. In fact, I'm barely even a hacker... Last edited by AC_Hacker; 01-05-15 at 12:10 AM.. |
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01-05-15, 04:04 AM | #1714 |
Supreme EcoRenovator
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IWarm,
Some of the best performing GSHP systems in the world use aquifers or rivers as their primary heat exchange fields. A prime example close to me is the Galt House East hotel in Louisville. It uses the third largest geothermal heat pump system in the world, pumping 7 million gallons per day from the Louisville aquifer into the Ohio river. The 4700 ton system is said to save $300,000 in heating and cooling costs per year over the adjacent, original Galt House hotel building. The original building runs off centrifugal chillers, a boiler, and a cooling tower. |
01-05-15, 09:08 AM | #1715 |
Apprentice EcoRenovator
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quick math:
7e6/4700 = 1489 gal/day per ton = 62 gal per hour = about 515 # per hour; or 515 BTU per hour per deg F Say incoming aquifer water is 60F, out = 35F (to avoid freezing evaporator) delta T = 25F, so 25*515 = 12875 btu/hr, how about that, the math is consistent with the numbers, did not look right at first. |
01-05-15, 10:22 AM | #1716 | |
DYIer
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Quote:
I don't like to argue, so I don't. As I read your drilling reporting, it seems to have said you found drier ground under a 'hardpan' and never found the water table. Only trying to help. IWarm |
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01-05-15, 11:05 AM | #1717 | |
DYIer
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Quote:
Finding the water table will go far to insuring good performance and is likely to also minimize field cost. IWarm |
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01-05-15, 12:13 PM | #1718 |
Supreme EcoRenovator
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if you want to maximize performance and minimize cost you can never do enough measuring ahead of time. if you're doing it yourself, there is plenty of time to piddle around and take many many measurements. contractors usually don't have this luxury.
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01-05-15, 10:46 PM | #1719 | ||
Supreme EcoRenovator
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Quote:
I believe that my general area is one of those, but I think that my specific location is not. What I was trying to convey in the 'Manifesto' was that I hit a year-round wet layer at 17 feet, then hard pan... so I stopped drilling. It is possible that if I went deeper, I might find more wet layers. However, I live on a bluff, with no higher ground anywhere close. There may not be any wet layers deeper down. > Only trying to help I'm not exactly sure what kind of help you are offering? Quote:
But enough talk of theory, the proof is in the pudding. I will very interested to see how your project progresses. Don't forget to include as much project detail as possible and lots of photos. This will help others who embark on similar projects in the future. Best of luck, -AC_Hacker
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01-05-15, 10:56 PM | #1720 | |
DYIer
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Quote:
IWarm |
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Tags |
air conditioner, diy, gshp, heat pump, homemade |
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