New geo system install

[skyking]

I was pointed here from ecomodder's forum, thank you piwoslaw.

My brother got a bid from a local contractor for geo and solar domestic water, and we are doing all the digging.
ClimateMaster Inc. - ClimateMaster Residential Units

That is the pump.
I'll get more details of the equipment for the solar and the heat exchanger. This system will pump excess heat from the solar panels into the ground in the late summer and fall. It is so effective, an unoccupied house that was not using domestic water for the summer ended up with ground temperatures of over 100 F!

First step, delete a 45' locust tree. Sorry, I forgot to take before pictures.


I dug down with the 4' smooth bucket to about 3.5' and found caliche, a form of hardpan. That was the first surprise. Next I "found" and repaired an undocumented sewer line to the neighbor behind. That moved our geothermal grid about 8' over in a yard that was too small already.
Now I'm down in the dig, switching over to the 3' bucket with the tiger teeth to get after the hard pan.



Getting dark on Thursday, I have about 80% of the excavation to depth.



We had fun finding places for all the dirt on a large city lot. Got dirt?



By the time I had it dug out, I had a little mountaintop to sit on and nowhere to go.



The contractor's crew fusing the 1.25" header onto the three 600' loops of .75" poly.



The loops have been filled and air purged, and under a pressure test. After filling the tubes can be arranged in the hole more easily.



The backill process begins. The soil was hand bedded over the pipe to insure good contact and no roots or rocks against the tubing.



We have a 3' lift over the pipe and have watered it in before compacting. Today we will install my innovation, a grid of drain pipe over that 3' of dirt.
The soils in this area are below optimum moisture for compaction whenever I dig it up, so I figure it will be below optimum for good contact as well.
I will put in a grid of perforated drain pipe and connect the downspout drains and yard drains to it to automatically keep the soils below moist.

[Blauhung]

Looks great so far. Please keep us updated

[skyking]

I compacted the first lift and graded it flat.


Rolling out the drain pipe.



My assistant and I cleaning up.......



We dug the header pipes over to the mechanical room of the new addition. Now we wait for permits and construction.

[Xringer]

Wow, an underground sprinkler system for heat exchanger that's even deeper down!

The idea of being able to pump heat into the ground all summer (while using the cooling mode),
and have that heat stored there in a mass of nice moist soil, until you need it during the winter..
Is pretty danged cool!

Keeping your subterranean heat storage area wet, without exposing your
precious rain water to the ravages of the sun on the surface is very smart!

This scheme seems like it's going to work much better than just dropping
the water on the surface of a lawn area.


The only drawback I can see with a system like this, would occur if there
was flowing ground water, which took away the heat before it could be
extracted during cold weather..
But, that flowing water would still be at 60-65 deg F (around here), which
is still not bad for extracting heat or pumping some in..

With no ground water, the only worry I would have is, over-heating the
storage so much, that your heat pump couldn't squeeze any more heat into it.
That would make it impossible to use the cooling mode.. Maybe during
a 100 deg August..?.


Keep on Innovating !!

Cheers,
Rich

[skyking]

Today we finished filling the hole and grading the yard, installing some irrigation pipe in the backfill.

There is some asphalt in the foreground. We removed that today in preparation for digging the footings.
Some finished views:






Asphalt is gone, ready for the footings.



Started on the crawlspace dig so we could bring the geothermal headers into the building envelope. Loop is charged and under test at 80 PSI.

[AC_Hacker]

skyking,

Thanks for the great pictures. I think that these photos are very motivating for anyone who may have an interest in building or contracting out a ground source heat pump.

Also, I'm very interested in the solar heat part of the setup you guys are doing. If there is any information and/or photos you could share about that, it would be very useful. Not only the collector part, but the plumbing, etc that keeps excessively hot water from doing damage to your loop field, and all pump sizes, etc.

Are you using an air handler for your heat pump, or a radiant setup?

Also, what was the heat loss you figured for your house when you did the design?

The house heat loss would be useful information to compare to the size of your loop filed and your solar component.

Thanks,

-AC_Hacker

[skyking]

Originally Posted by AC_Hacker

skyking,

Thanks for the great pictures. I think that these photos are very motivating for anyone who may have an interest in building or contracting out a ground source heat pump.

Also, I'm very interested in the solar heat part of the setup you guys are doing. If there is any information and/or photos you could share about that, it would be very useful. Not only the collector part, but the plumbing, etc that keeps excessively hot water from doing damage to your loop field, and all pump sizes, etc.

Are you using an air handler for your heat pump, or a radiant setup?

Also, what was the heat loss you figured for your house when you did the design?

The house heat loss would be useful information to compare to the size of your loop filed and your solar component.

Thanks,

-AC_Hacker

It will be months before the addition housing the systems will be completed. I'll update the thread as things happen.
The original house is 1920 craftsman construction, and will have ducting and an air handler.
No idea on heat loss calculations.
The solar is for domestic hot water primarily. It is a separate system with glycol, the ground loop will be methanol.
It will have two collectors and a pump, a heat exchanger to the ground loop system, and a triangle tube boiler tank to exchange heat into the domestic hot water. It will have very small volume, and an expansion tank to cope with the extreme temperatures and pressures solar can get to when things go wrong.
When the triangle tube tank reaches operating temperature of 140 F, it will then begin to exchange heat into the ground loop on the return line.
Triangle Tube 80 Gallon Smart Tank | SolarTown: Solar Water Heaters, Storage Tanks

That is what I know for now. I'll post more as things develop.

[AC_Hacker]

Originally Posted by skyking

When the triangle tube tank reaches operating temperature of 140 F, it will then begin to exchange heat into the ground loop on the return line... I'll post more as things develop.

Well... it may never become an issue, but I think that the HDPE has a maximum temp rating of 180, after which it gets soft.

It could be a good idea to have a failsafe circuit that would sense for over-temp situations and could act to prevent damage. I have heard of flat plate solar panels easily reaching 212F.

-AC_Hacker

[skyking]

Originally Posted by AC_Hacker

Well... it may never become an issue, but I think that the HDPE has a maximum temp rating of 180, after which it gets soft.

It could be a good idea to have a failsafe circuit that would sense for over-temp situations and could act to prevent damage. I have heard of flat plate solar panels easily reaching 212F.

-AC_Hacker

Yes, that won't be an issue.
The heat exchanger is metal, and Solar will not flow into that unless Geo is flowing as well. The earth won't ever get to a temperature to cause that type of failure.

Wow! This is amazing info. The way the construction is going is great. Thanks for providing such a great post in this site.