Geothermal experiences appreciated
Movi...@gmail.com
geothermal. I'd love anyone who has installed geothermal in a
residential home (preferably converting from another heat source) in a
cold climate area (I'm in the upstate NY area) to share the following:
-- anticipated and actual heating/utilities savings (or not)
-- the size (in tons) of your system
-- if you have an open or closed source
-- if you had to rely on backup heating
-- your rough location (so I can compare climate similarities or
differences)
Right now, even with the high capital cost of installing a new
geothermal unit, I'm looking at an approximate 5- to 6-year payback on
this system. It's a very attractive proposition.
Thanks!
hubops
Yes. Thanks for asking !
I'm in southern Ontario - also thinking of geo-thermal.
Anyone's real-life experiences are welcome.
A few of my neighbours have converted - but quite recently
so the results aren't in yet, for them.
I believe that I can expect to spend around 20-25 k
and get about 8 k back in grant money.
I would like to keep my new hi-eff propane furnace
for January-February aux. heat. I would hope that the
geo-thermal would provide central air cond. (new)
and reasonable March-April-Oct-Nov-Dec heating.
I have a half acre lot - but septic field would limit
excavation to a U shape - around it - for buried piping.
I have a good drilled well source - but not sure about
using that for geo-thermal
( I think that 2 of my neighbours are already tapped into the aquafer
for geo-thermal - and discharge to the storm sewer )
.. seems if we all did that - we'd be sacrificing our drinking water ?
thx John T
Mike Copeland
involving lots of PVC pipe laid out under the surface of the ground. It
started to leak.....no one could fix it. The HVAC people in the area
tried, the plumbers tried... we put in a heat pump and never thought
about it again.
The moral is to be very sure that you have a local support system to
call on when you need it. Off the shelf parts/systems are MUCH easier to
maintain. The money you think you will save in the long run can be wiped
out with just one "issue". Dependability trumps ALL other issues.
Ken Maltby
<Movi...@gmail.com> wrote in message
news:80ce5022-78b5-44a9...@m45g2000hsb.googlegroups.com...
I suspect what you are describing as "Geothermal" is also known
as a "Ground Source Heat Pump".
What some of us think of as Geothermal requires tapping into the
high temperature areas of the earth's crust that are only practically
exploitable at certain spots. Unless you have steam rising up from
the ground or bubbling mud on your property, it's not likely that
you would be able to access that kind of Geothermal.
What has been a puzzle to me is; why hasn't Westinghouse
or some such, found a way to get between the hot magma and
the giant cold water heatsink that is the ocean, at any of the
many points where this is occurring naturally now. Or perhaps
use a short drilling into the ring of fire, where it is near a major
city but out at sea. Providing Tokyo, LA, Hong Kong,
Singapore, San Francisco and many others with a truly vast
continuos source of power, would drastically cut their need to
import oil.
Luck;
Ken
http://www.treehugger.com/files/2008/03/geothermal-is-not-a-heatpump.php
phil-new...@ipal.net
| What has been a puzzle to me is; why hasn't Westinghouse
| or some such, found a way to get between the hot magma and
| the giant cold water heatsink that is the ocean, at any of the
| many points where this is occurring naturally now. Or perhaps
| use a short drilling into the ring of fire, where it is near a major
| city but out at sea. Providing Tokyo, LA, Hong Kong,
| Singapore, San Francisco and many others with a truly vast
| continuos source of power, would drastically cut their need to
| import oil.
Because the government isn't subsidizing the effort and giving them a tax
credit for what it costs.
--
|WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance |
| by the abuse department, bellsouth.net is blocked. If you post to |
| Usenet from these places, find another Usenet provider ASAP. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |
Neon John
>On Wed, 23 Jul 2008 21:31:49 -0500 Ken Maltby <kma...@sbcglobal.net> wrote:
>
>| What has been a puzzle to me is; why hasn't Westinghouse
>| or some such, found a way to get between the hot magma and
>| the giant cold water heatsink that is the ocean, at any of the
>| many points where this is occurring naturally now. Or perhaps
>| use a short drilling into the ring of fire, where it is near a major
>| city but out at sea. Providing Tokyo, LA, Hong Kong,
>| Singapore, San Francisco and many others with a truly vast
>| continuos source of power, would drastically cut their need to
>| import oil.
>
>Because the government isn't subsidizing the effort and giving them a tax
>credit for what it costs.
The energizer bunny of idiocy is at it again. Sheesh. If ever the old
expression "Better to remain silent and be thought a fool than to open your
mouth and remove all doubt" applied to anyone, it'd be you.
Ken,
The reasons are many. Probably the most serious is how thick the crust is in
most places. I think that the Russians still have the record for the deepest
bore hole at about 10 miles. That was a Herculean effort and was more for
bragging rights than anything else.
The Russians have developed the a-biotic theory of petroleum that says that
petroleum is not dead dinosaurs but instead was formed in primordial times as
the earth's crust cooled. There is enough evidence supporting that theory
that I'm now paying attention. One prediction is that almost regardless of
the location of a well, if drilled deeply enough, it will strike oil. They've
been remarkably successful in that endeavor. The 10 mile hole was in part, to
test that theory at extreme (for us on the surface, anyway) depths.
During the Cold War the West poo-pooed that theory because, well, anything the
Sovs did was pure evil. Now that that's all behind us, the theory is getting
a new hard look. I think that they're on to something.
Even where the crust is thin to the point where a borehole would reach the
magma or at least the boundary, the problem then becomes recovering the heat.
The borehole itself might be a foot to 18" in diameter. Even if it were
somehow possible to bore far into the hot stuff, the exposed surface areas is
tiny. Rock is a poor conductor of heat so once the rock near the hole has
been cooled, little heat is available.
One of the tests planned for Project Plowshares (nuclear explosions for
peaceful use) that was never carried out was to see if a useable cavity could
be melted/shattered in the hot stuff sufficiently large to be useful.
Nukophobia stopped that experiment. From what I've read, the major issue was
whether the hot rocks would be too plastic to shatter. If the cavity were to
be created as a smooth glass-lined chamber, it would be of little use. This
was a problem in the related experiments that WERE conducted to see if gas
production could be enhanced. The rock tended to melt rather than shatter.
The rock would have to shatter over a large distance to allow water or a gas
to penetrate it and be heated.
Another reasonable concern is that if one were to bore into the hot zone, he
might just create a volcano. Fairly unlikely but not a probability of zero.
You might have heard about the Paricutin volcano in Mexico that birthed itself
in a farmer's field in 1943.
http://www.rumela.com/travel/paricutin_volcano_index.htm If that can happen
with no assistance from man then one would want to be cautious in tickling the
tail of that dragon.
The existing geothermal regions are unique in that just the right rock
formations exist over and through the hot zone so that water can seep or be
pumped in and steam escape. This requires a huge surface area of rock to be
exposed to the water, something that would be extremely difficult, probably
impossible without the use of nuclear devices, to create elsewhere.
Finally, there is the whole return on investment thing. As blue chip publicly
owned companies, the major oil companies are obligated to produce the best
possible return on investment for their owners, the shareholders. It is
acknowledged by the market that applied research - research to adapt and
perfect existing technologies to oil production - and some basic research -
looking for new techniques and methods likely to work is necessary for the
future of the company. However, blue sky research, as creating new geothermal
fields would be, is generally tolerated only in tiny amounts by the
stockholders.
Most any research funded by publicly owned companies has to have at least a
plausible possibility of being economically viable sometime in the future.
Even if the experiments to create new geothermal fields were successful, the
costs would likely be too high for the energy to be competitive in the
marketplace.
Blue sky research is the province of speculators, venture capitalists, angel
investors and unfortunately, us. "Us" by virtue of the money the government
takes from us and spends on things we'd consider frivolous if asked to fund
out of our pockets. While all the other source of research funding need to
see at least a small probability of something productive resulting, the
government doesn't. It's the master of spending OPM (other people's money) on
boondoggles. That's not news to anyone.
This is one of those concepts that sounds really nifty until one starts doing
the math and the science.
John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
To have doubted one’s own first principles is the mark of a civilized man -Oliver Wendell Holmes Jr.
Ken Maltby
"Neon John" <n...@never.com> wrote in message
news:sfrj8495jjbc68cmn...@4ax.com...
> On 25 Jul 2008 00:07:19 GMT, phil-new...@ipal.net wrote:
>
> The energizer bunny of idiocy is at it again. Sheesh. If ever the old
> expression "Better to remain silent and be thought a fool than to open
> your
> mouth and remove all doubt" applied to anyone, it'd be you.
>
> Ken,
>
<<Pause>>
I expect that sooner or later someone "doing the math and science"
will find a way to take advantage of this prime example of a Second
Law opportunity. Someday we will have the materials to extract heat
from the flows of magma, so that even a very large extraction of heat
would not cool the moving magma enough to cause it to solidify.
There would be some intermediate high temperature fluid (a metal alloy
perhaps) to bring the extracted heat into the power generation
system. (Perhaps through several stages.)
That much Delta won't be ignored forever.
So long for now, I have to go change my batteries.
Luck;
Ken
Bruce Richmond
> On 25 Jul 2008 00:07:19 GMT, phil-news-nos...@ipal.net wrote:
> with no assistance from man then one would want to be cautious in tickling the
> tail of that dragon.
I remember reading about something like this happening in, I think,
the Philipeans. A well for natural gas allowed ground water to seep
down to where it was super heated and came back up a short distance
away as a mud gusher. The mud keeps coming and the land in the area
is sinking.
> See my website for my current email addresshttp://www.neon-john.comhttp://www.johndearmond.com<-- best little blog on the net!
> Tellico Plains, Occupied TN
> To have doubted one’s own first principles is the mark of a civilized man -Oliver Wendell Holmes Jr.
I think there are many places where it could be made to work, but
investors want things that they *know* will make money. There are
quite a few geothermal plants being built in the western US. For the
most part they want rocks hot enough to super heat steam. There are
ways of using lower temp heat sources as well though.
http://www.yourownpower.com/Power/
Bruce
Fat Moe
Saturday mornings. Over and over it's stop the infiltration of outside
air, insulate (with cellulose), proper windows, and geothermal. He
says the number one obstacle is getting contractors, who have done
things the same way for so long, to change.
http://www.dougrye.com/
Google "doug rye listen live" to find a streaming site to listen to
him .
Reno
heating sytem is paying off - starting third winter now. The house is
5,000 sq ft on 2 floors plus a finished basement with a walkout so we are
servicing 7,500 sq ft. Our electric bills have been about $300 to
$350/month, about $3,900/year. We have every electrical appliance and toy
imagined plus a hot tub on the deck which is used year round. We are in
Winnipeg, Manitoba which is pretty cold. Or electric utility, Manitoba
Hydro, has a web site with an energy calculator that showed our heating
costs would have been $4,000/year with gas and $2,000/year with
geothermal and this seems approximately correct with our experience. We
are on track for a 10 year payback. However, that doesn't count all the
time I have spent battling air locks in the injection well plus
chlorinating and acid treating the wells - apply my professional charge
out rate to my time off work and we are losing $5,000/year to the
hassles. The choice of open-loop is the killer error we made - it is a
huge horror story. even the choice of a crook for a contractor was minor
compared to chosing open-loop.
Would I do it again? Yes because I can now design and inspect these
systems, especially with the advantage of hindsight and hands-on
experience. Would I recommend it to someone else? No way - because there
are so many pitfalls that I wouldn't want to be involved.
We have a 3-ton unit for the second floor and a 5-ton unit for the first
floor, basement and crawlspace under the basement structural floor. They
are ClimateMaster Tranquility 27 units with an open-loop. The auxiliary
heat has never come on even on minus 38 degree Centigrade nights with a
howling wind.
The heat pumps work well but the open-loop is a collosal pain in the
butt. The wells are infested with iron bacteria which requires cleaning
the filter every few weeks - takes me 5 minutes. The injection well has
air-locked twice now - first time after 2 months of use and the second
time after 10 months. I have re-designed the injection well pipe system 3
times now to try and improve the air locking situation. Gets better each
time, next time ought to do it.
I do NOT recommend an open-loop and consider it a huge mistake. A closed
loop would have avoided a lot of on-going troubles. Humans have been
getting water out of wells for thousands of years and we know how.
Injecting water down a well is a new trick that has many variables
frustrating the effort and is a real trial and error process.
The injection well overflows when it gets air locked. It is a good thig
our property is large enough to contain the overflow - for 4 months the
first time. Had it overflowed towards a neighbors house we would have had
to either switch to the electric auxiliary heaters or try and fix it in
mid-winter. The solution was to pull out the discharge pipes and drop in
a well pump to reverse the flow and get the air to come out. That is
almost impossible in 30 below weather - things would freeze up
constantly. In many locations there is nowhere to pump to - can't pump to
a sewer for the 3 days it took before the air finally let go. The second
time the air lock was caused by very small bubbles which travelled
farther into the limestone formations and thus wouldn't let go until I
pumped for a week at double the usual rate. Good thing I could pump onto
our own property! The concern with air locking is that the reason air
comes out of solution with the groundwater, pressure drops, also cause
calcium and other minerals to also come out of solution. These deposits
block the limestone formations and reduce well capacity. The solution is
to pump industrial strength acid into the formations to eat out the
fracture zones. Works good but causes a huge gieser of foam, gasses, air,
water and acid by-product. I aimed it at the lawn but where would a
normal resident direct such discharges? You would need a tank truck to
help at considerable cost. These are just a few of the basics of open
loop hassles and costs - they will go on forever - all I can do is re-
design the entire piping system and try to run the system at a higher
pressure which will reduce the tendency to air lock and deposit minerals.
My research shows that well maintenance, by acid treatment, is always
required for all injection wells - nobody told me at the beginning. The
only question is can I get it from yearly to maybe every 5 years? Note
that the best geothermal firm in town designed and installed this sytem -
the equipment and pipe sizes they chose all need to be redesigned at my
cost. "This is the way we always do it and it works the rest ot the
time."
However, closed loop systems require careful design as to layout, type of
pipe, depth of bury, and most critically, soil moisture (for horizontal
loops). Dry soil does not transfer heat very well - wet soils are great
for heat transfer but terrible to work in for the installation. Dry sand
has air in it which is an insulator and thus impedes heat transfer and
reduces the efficiency or capacity of the collector field. Most
installers use sand backfill to protect the pipes from crushing by clods
of earth. If the groundwater is below the trench the sand will dry out
and the field will not transfer enough heat unless it has been designed
and sized for dry sand. Some guys will design for the damp clay
surrounding the trench full of dry sand. Backfilling with thermal grout
makes the installation efficient but more expensive.
Vertical loops are better but require a lot of connections all of which
are prone to leakage if not done right. Also, vertical loops use 50 ft
deep holes, or deeper, but the connecting pipes are typically installed
only 3 feet down which is within the 6 to 8 foot deep frost zone around
here. So a lot of the heat brought up from the depths is lost enroute to
the house - nobody will insulate the collector pipes. I went through this
with several of the bidders on our system.
My experience is that the geothermal industry is over-loaded with get
rich quick artists with little technical competence and less ethics. The
capital costs are in no way warranted by what are essentially simple and
cheap systems. I got several excellent references for my first HVAC guy
but then he started demanding $10,000 advances before doing any work, he
used the world's worst well driller for our wells and then the police and
tax collectors showed up - police wanted to arrest him for taking 5
figure deposits from other people and never doing any work and the tax
guys wanted to garnishee anything we might ever have paid him. We fired
him and got a new company that was pretty good but then it was a case of
them not warranting anything the first guy did - logical. There are some
good contractors, I think our second one is, but they are few and far
between and tough to identify. I found as many good references for the
crook as for the second company. The crook did just enough good honest
work to get references for his real scam.
There are guys installing horizontal loops only 3 feet down in our area
(had one guy quote this)where the frost goes 6 to 8 feet down. Sure you
can suck energy from frozen soil but the hit in efficiency is significant
and prevents re-couping the investment. We have friends with geothermal
heating, open loop, who are paying more for heating than they did with
their old natural gas system. Geothermal thermostats have red indicator
lights showing when the electrical auxiliary heat cuts in and the red
lights are on most of the winter - so they essentially have an
inefficient electric furnace. They were ripped off by an uneducated
installer and incompetent well driller - their wells are very shallow,
the same depth casings and very close together so the water simply short
circuits - after a day or so they are re-pumping the same water and the
flow path through the ground between wells is too short to pick up much
heat. The geothermal heat pumps loose efficiency quickly with lowered
temps for the incoming water. Since open loops are pumping water, not
anti-freeze, there is a safety shut-off required to prevent cooling off
the water so much that it freezes and bursts the heat exchangers. Thus
their geo system often shuts down and reverts to electric - most of the
time. The electric auxiliary heat is just a few cheap wire coils (looks
like a 1960's portable heater) which are much less efficient than a
modern electric furnace. Their contractor is out of business, or has a
new name, and the well driller was only responsible for doing what he was
told by the contractor so they are left with no recourse at all.
Closed loop systems require a special thermal grout to achieve good heat
transfer from the soil to the pipes but the suppliers I spoke with don't
even import that stuff into our province despite several thousand systems
having been installed. Vertical systems should have spacers between the
pipes to locate them as close as possible to the hole walls and thus get
the best heat transfer - I watched two installations at other houses and
they not only didn't use spacers but taped the pipes together to make
them easier to force down the hole. "We always do it that way" was the
response to my question.
In summary - geothermal works and the cost savings are there but the odds
of getting ripped off and getting an inefficient system are very good -
research the contractor more than the system. All the sytems work well if
properly designed and installed, few of the contractors do. Don't go
open-loop no matter what they tell you. Open-loops suffer from iron
bacteria, calcium deposition within the pipes and heat exchangers, air
locking causing the injection well to over-flow (try fixing that in the
winter while water flows into your neighbor's yard and imagine how much
you are going to get sued for if it reaches his house), poor well design,
poor well drilling and lots of things that I forget right now or haven't
happened to me, yet.
The most irritating thing is that the initial costs are grossly inflated
because it is a whatever the market will bear industry. Geo wells are
simpler and cheaper to install than water wells but you get charged a lot
more "because it is geothermal". Use only a firm that has been in
business for many years - a lot of the companies around here are new or
are changing their names every few years. The many poor installations are
starting to pile up and when the warranty hassles get too much it is
cheaper to kill the company than do the work. Many geothermal errors are
very expensive to fix - a new well is $10,000 to $15,000 IF a drill rig
can get into the site after the house is built, same sort of costs to fix
closed loops. Double those costs for expensive landscaping that has to be
torn up so repairing a geothermal system will cost over $20,000 and could
hit $30,000 to $50,000. Well infections can never be cured, according to
all my research and best efforts so that's a permanent problem. Note
injection wells spread the infection throughout the groundwater formation
so disinfection is not like a simple farm supply well where some Javex
will do the trick. Drilling a new well doesn't help because the infection
covers more than just your yard. The lack of talent in the industry
causes so many of these problems that the small cheap companies can't fix
the problems they cause.
If you do go open-loop get at least 5.5 inch inside diameter casing. Case
one well at least 25 feet deeper into the rock than the other (offset
casing depths so at least one fracture zone is not common to both wells -
lots of luck getting driller to actually do it, install a double pitless
adaptor and double pipes into the house (both wells; you'll need them
sooner or later), locate wells at least 250 feet apart (can trade this
spacing for more vertical offset in casing depth if in limestone), get
best well driller you can find and make sure he, and everyone who works
on the well, disinfects after working - a bottle or two of Javex at the
time by driller and installer would have saved us a permanent
disinfection hassle. These are just some of the things required that you
will get resistance on when you deal with contractors. Our first
contractor, the crook, had the well driller install a 5 inch casing but
with the double pitless adaptor there is not room for a standard 4-inch
pump so we are forced into expensive 3-inch pumps that are much less
efficient. The well driller knew standard pumps wouldn't fit but he was
going to get paid before we tried to install the pump.
If you go closed loop make sure they use thermal grout or, better yet,
that the pipes are in wet soil all year round (near the septic field is
very good, thermally, but not so great if you ever have to search for and
repair a leak), bury pipes at least 6 feet and over-size the collector
field or at least make contractor produce the calculation sheet and give
you time to check it out.
Either horizontal or closed loops require at least a hundred heat welded
connections that MUST be leakproof. Now imagine a contractor paying
minimum wage to his guys to do such finicky work in the dust and dirt -
never mind if it rains and mud is smeared on everything. It only needs to
pass a pressure check, done much less carefully if you are not watching,
and not leak until the cheque clears. Only the very best firms are worth
risking this sort of work with.
Something else I learned the hard way - use only one heat pump! We have
two heat pumps and many of the problems are due to use of two heat pumps
on one open-loop. Dividing the supply flows is a root cause of huge
problems and that would also be true for closed loops, maybe worse for
closed loops. Flow splits require use of balancing valves which are
actually pressure reducing valves (PRV's). They work by throttling down
flows through each heat pump to balance the flows. The trouble is
throttling flows causes gassing - that is the hissing sound these valves
make - solid liquid does not hiss. All installers use PRV's to balance
flows and the results are air locked wells or air locked closed loops.
Much better to use a larger heat pump and design a zoned system for the
house. All the bits are accessible and a bit of trial and error is
simple. NEVER allow a PRV on a system, closed or open loop. Nothing but
trouble. Size the pump for a bit more flow than needed and use a variable
speed pump to adjust flows further. NEVER NEVER use a PRV!!!! A single
variable speed supply pump and a single heat pump is simple and has the
best odds of working with minimal hassles. PRV's guarantee trouble - I
told my installers "no PRV's" but they insisted and said if they caused
any trouble they would take them out. The next year when the well
overflowed there were huge bubbles coming out the top which came and went
when I opened or closed the PRV. So they removed the PRV's and replaced
them with orifices at the ends of the discharge pipes which I wanted all
along. Then they sent me a bill for $2,200 for "improvements at your
request". Best I could do was negotiate that to half. Remember, PRV's
hiss which is air or gas and that air/gas is going into your well or into
hundreds of feet long closed loop pipes. How are you going to get the air
out? Who is going to pay for fixing air locks? It won't be the guy who
installed the PRV "because I use them all the time and they never did
this before". Agravating thing is PRV's are NOT required as there are
options which don't cause air locks.
Fixing air problems in wells or pipe loops is as complicated as debugging
a computer program with no end of possibilities and ways to deflect
blame. It is a time consuming hassle and thus expensive to pay someone
else to fix. Unless all the possible causes of air locking are found and
corrected the problem will reccur and always at your expense. NO PRV's
!!!
Movi...@gmail.com wrote in news:80ce5022-78b5-44a9-9840-274b939ff6d4
@m45g2000hsb.googlegroups.com:
zero
Thank you for taking the time to type all of the above info.
I'm not using any ground source heat pumps, but am researching
building such.
Again, thanks.
zero
John Gilmer
That's a very interesting and potentially very useful report.
Just some random comments/questions. Note that I don't have any
particular expertise so I may be asking "dumb" question or making foolish
comments. I beg forgiveness in advance.
When you have "air lock"problems and have to "dump" the water on the ground,
did you consider spraying the water into the air to generate a pile of
frozen "snow/ice?" When the outside air is below freezing, you can "warm"
the air somewhat.
Some rural folks consider "shocking" a drinking water well just normal PM.
Basically, they dump a few gallons of bleach down the well. Did you try
that?
Did anyone suggest/try "degassing" the dischanrge water before discharging?
Before leaving your home the water would enter an air over water tank with
an air pump that would keep the tank under a slightly reduced pressure.
Depending upon the details of your discharge well you might want a check
valve at the bottom.
Your neightbors who end up using resistance heat much of the time might
consider just running the ground source heat pump at whatever rate it can
maintain without risk of freezing. A variable speed blower in the air
handler can help. Rather than use the "strip heaters" in the air handler,
just get a few electric heaters with thermostats and run them where the
people are.
Keep in mind that all I have is a conventional air source heat pump. Our
system has 60 amps worth of "strip heaters" for auxilary heating and for
keeping the chill off when the outside unit goes into defrost mode. I
disconnected 40 amps worth (2 of the 3 "strips") by shifting the wiring so
that the fan and transformer are on the circuit with a single strip and the
other two strips are on a separate breaker. The house can get a little
cooler but the room heaters put the heat where we need it when watching TV,
etc. Were my heat pump to fail, I call always restore all my aux heat by
flipping the breaker back on.
We also have an LPG fired ventless heater in the family room. This room is
at the far end of the house and over an un-heated garage. I understand
that ventless units are illegal in many places and the fumes disturb some
folks but we have no problems (legal or health.)
We use a very experience and honest "HVAC guy." When I asked him about
grothermal, he just said: NO.
Michael B
> However, closed loop systems require careful design as to layout, type of
> pipe, depth of bury, and most critically, soil moisture (for horizontal
> loops). Dry soil does not transfer heat very well - wet soils are great
> for heat transfer but terrible to work in for the installation.
Closed loop with a septic system leaching field over it could be
considered. Even a greywater delivery field could help make sure
thermal conductivity was maintained.
Michael B
> We use a very experience and honest "HVAC guy." When I asked him about
In every profession, a few professionals and a lot of amateurs.
Regardless
of their level of experience and honesty.
Reno
>
> When you have "air lock"problems and have to "dump" the water on the
> ground, did you consider spraying the water into the air to generate a
> pile of frozen "snow/ice?" When the outside air is below freezing,
> you can "warm" the air somewhat.
>
The first winter we were in the house the injection well overflowed by the
end of January. Our winter air temps are way too cold for normal water
pumping. I just allowed the overflow to go overland until it soaked into
the ground below the snow somewhere. I could have made snow but dealing
with water pipes and pumps in the winter is a lot of trouble. All pipes
must be drained within minutes of stopping the flow or they freeze up. I do
use the well pump once a winter to refill the hot tub but I pick nice sunny
afternoons with only about minus 5 degree Centigrade temps - happens a few
times each winter.
> Some rural folks consider "shocking" a drinking water well just
> normal PM. Basically, they dump a few gallons of bleach down the well.
> Did you try that?
>
Boy did I ever! the problem is that geothermal differs from normal farm
wells where they only pump out of a single well. Disinfection is easy
because the pump keeps the bacteria close to the well where the chlorine
can kill them. In geothermal two well systems there is some flow through
the groundwater formations between the wells. This is great from a heating
point of view because the water picks up heat as it travels. From an
infection viewpoint it is terrible because bacteria get spread throughout
the rock formations and the chlorine can't get at all of them so enough
remain to re-infect. I researched the heck oput of well disinfection and
then tried a program of shock chlorinating followed by injection of
chlorine into the discharge piping for a 2 week period. I used up 19
carboys (20 liter barrels) of industrial strength chlorine. The infection
returned within 3 months.
> Did anyone suggest/try "degassing" the dischanrge water before
> discharging? Before leaving your home the water would enter an air
> over water tank with an air pump that would keep the tank under a
> slightly reduced pressure. Depending upon the details of your
> discharge well you might want a check valve at the bottom.
>
The check valve is good thinking and I am using a variation of that - I
installed orifices on the ends of the discharge pipes to throttle the flows
down to the required rates for each heat pump. The idea was to maintain
high pressures within the pipe systems ro prevent gassing. It worked to the
extent that the well lasted 10 months instead of 2 months before
overflowing again. It created a worse problem in that the bubbles were now
very tiny and got carried farther into the rock formation which made it
very difficult to solve the airlock by reverse pumping. Bubbles got in the
rock far from the well are in zones where water is flowing very slowly
towards the well and so has little force to move the bubbles. I could only
restore about half the capacity by reverse pumping. I restored the full
capacity by acid treating the well. When the acid hits the limestone it
eats it up pretty good and causes a lot of by-product gasses to form very
violently. This causes a very violent gieser to erupt from the well top
which I control with a well seal and vent pipe leading to a safe area. The
gieser removed the rest of the air and combined with the acid eating the
formations into larger cracks restored well capacity to better than
original.
Your air over water tank suhgestion refers to air removal tanks which are
readily available but not suitable to geothermal applications. Ground water
contains dissolved air, gasses and minerals. I researched them, too. When
the pressure is reduced all three of these are released. This happens in
air removal tanks. The air removal would be great but the mineral
deposition would plug up the heat exchangers if the tank were upstream and
would plug the groundwater formations later.
The trick is to keep the system pressures as high as possible, avoid or
minimize pressure drops through all parts of the system and locate the
orifices as deep below the water surface as possible. Depth increases local
pressure and reduces gassing and mineral deposition. My problem is that I
can reduce air locking but not eliminate it. It is very frustrating that
reduction of gassing also results in smaller bubbles which eventually air
lock the formations but do it so far from the well that air removal is
almost impossible. I have solved 99% of the gassing but the remaining 1%
still causes air locking and makes it much more difficult to cure. The
choice was large bubbles airlocking in 2 months but solvable with minor
reverse pumping effort or tiny bubbles air locking ion a year or so but
requiring huge reverse pumping efforts plus acid treating to remove. The
acid is dangerous to handle and use. It is not a minor issue.
For my next trial I am comparing Plan C - upsize all of the pipes and the
pump pressure and increase the length of the discharge pipes to Plan D -
leave pipes as they are now and install some method of causing the tiny
bubbles to flow upward instead of downward. Plan D appeals because it will
get any bubbles that may occur out of the water. I am looking at putting
the two small discharge pipes within a larger pipe that has it's top above
water in the injection well. The orifices will stay at the bottom of the
discharge pipes so water will have to flow upward and then overflow the
larger pipe and drop gently into the well. I hope the bubbles will be
released above water. This plan may work better if I go back to the large
bubbles setup because large bubbles will separate from the water more
easily. It's a theory.
> Your neightbors who end up using resistance heat much of the time
> might consider just running the ground source heat pump at whatever
> rate it can maintain without risk of freezing. A variable speed
> blower in the air handler can help. Rather than use the "strip
> heaters" in the air handler, just get a few electric heaters with
> thermostats and run them where the people are.
>
Up here the minus 20 degree days are considered warm. We get Minus 30 most
nights and often colder yet. When it is this cold all rooms without a lot
of het are very cool. the problems are not just confort but also moisture
control. Cool walls allow for condensation which travels into the walls and
rots the house. If a room isn't warm enough we can get frost formation on
the walls or ceilings which would destroy the structures. We can allow some
rooms to be a few degrees cooler than others but we have to have
significant heat into all rooms. The outside temps just suck the heat out
of the houses.
Reno
> Closed loop with a septic system leaching field over it could be
> considered. Even a greywater delivery field could help make sure
> thermal conductivity was maintained.
Yes this would be great for thermal condctivity. I sure wouldn't like to
search for and fix a leak though. PE pipe properly heat welded by true
professionals and pressure tested would be a good system with least
potential for leaks. I would trust such a system.