Virginia New Geo - DIY - SW Virginia

Started getting pipes in the ground today. Doing 4 horizontal loops, 700 ft, non pressurized, DIY manifolds, and added 2 more loops for future addition.
Replacing a 3Ton Trane air unit after 18 years. Upstairs unit is a 2 ton, and probably replace it in the near future.

While I had the project going, I added 2 700 ft loops and manifold for if and when the upstairs HP dies.

Built my own manifolds, added pressure gauges to all four.

More posts as the project progresses.

Several people responded to some other threads, I appreciate them taking their time and answering my questions.

 

Ill post pics when I can figure out how.....

 

You have six, 700 foot loops available. Plenty of capacity. Why not install a 5T water to water heat pump off your ample loop field and zone from the heat pump to upstairs / downstairs air handlers via a buffer tank ?

 

What will the pressure gauges do for you?

 

Efficiency of water-water using air handlers is significantly lower than water-air ....

You can either zone the air with a single heat pump, sometimes tough to do in a retrofit, or you can use 2 heat pumps.

Multiple heat pumps requires some skills for pressure drop calculations and pumping power. Usually not a DIY.

 

Doc, my thought of the pressure gauges would make it easy to pressure test the lines during install ( with air ) and then be there if I suspect a leak later on.
I dont expect there to be much indication if its working right.

I have the first 75 ft installed, waiting on the rain today.

I chose to stay with two HP, the upstairs unit is a 2 ton, still working, so Ill use it till it dies, since its paid for. Then when I do change, I have the 2 loops already installed. I am putting in 6 loops, 4 for the 3 ton, 2 loops for the 2 ton. With the air units, the upstairs was mostly for cooling, and did not run very often. I have explored adding duct and combine it all but getting duct work connected would be a huge mess.

All loops pressure tested good. So far so good.

 

Sounds good.

 

First loop in the ground. Hit some ground water and caused the install to go much slower. But on the good side, the ground water will make the transfer better. Dept averaged 6.5 feet.

 

Main ditch going out.

 

Header

 

What kind of fittings are those on the loop pipe? Where did you get them?

 

Arkie, those are compression fittings, purchased from Geohydro Supply in Ohio. They worked great and no issues with the pipe. I also bought my pipe from them. Very friendly, helpful and great service. Sched 40 pipe purchased from Lowes, ball valves from Rural King ( better price ).

https://geohydrosupply.com/compression-adapter-3-4-pe-x-3-4-fpt/

Randy

 

Pretty dry soil...and pretty close together.....

 

Doc,
Thats just the 6 loops leaving the basement going out about 75 ft, then the loops disperse out. I did the 6 return on the bottom, then back filled 1.5 ft then the 6 outgoing on top.

Two loops are now in and back filled. Ground water and damp soil all the way. Depth is between 6 and 7 ft.

 

A couple of comments

A. The loops disperse out after 75 feet - what does that mean and what is the pipe configuration after 75 feet
B. I doubt there is much if any heat transfer in this first 75 feet - pipes are too close together. Why was the decision taken to run the loop pipes back to the residence instead of using a 1 1/4 or 2 inch header pipe and buried manifold to the point where the loops disperse out.
C. Charts from Siegenthaler suggest that the heat transfer per foot of trench per loop from a six loop over and under configuration could be as little as 1/4 versus a two pipe on bottom arrangement. So the first 150 feet of your 700 foot loops are of little benefit. So at best you have six loops of 550 feet each for a five ton system (including the upstairs heat pump). That may be insufficient depending on how the loops were dispersed after 75 feet.

 

Ok, that clarifies it.

Thanks

 

I wanted the manifold and connections inside. The six pipes share the one ditch for the 75 ft to get out away from the house to the field area that I wanted the loops. Four loops are for my 3 ton unit. The other two loops are for the future replacement of the upstairs 2 ton unit.

For Wing:
A: At the end of the 75 ft ditch, each loop goes into a 2 ft wide, 6 to 7 ft deep ditch, and runs until the end of the loop. So the way it fans out is three loops on the left, three on the right. Each ditch for the loops are at least 12 ft apart, mostly because I had plenty of room and the way the back filling worked out, it was easier. The loops are all located under a corn field.
B: I kept all six "return" lines together and all six "outgoing lines together, separated by over 12 inches of backfill. The idea was to isolate them if there was any transfer, but mostly because iit seemed a logical way to route them.
C: The calculations I did was using 250 ft of loop, even tho I actually have 275 ft of loop. Four loops for the 3 ton unit showed to be fine, based upon a 6 ft bury depth, which I exceeded in all four loops so far, as well as the loops are all in moist clay with underground water plentiful.
D: The soil in that section was solid but the placement was done with a 10 ft conduit with a clip to allow moving the pipes, a hoe, rake and a shovel. In the one area where I had to get into the ditch, it was dug out wider, sides layered and was 40 inches deep at the house entry. I took my time, had some help and got them layered in nicely.

Hopefully that clears up any confusion.

 

5-1-19 Update: Four loops are now installed, 2 backfilled, last two loops are ready to go in... delayed due to heavy rain.

All four loops are down at least 6 ft, most near 7 ft, because digging went good and I found a layer of wet gray clay and the pipe almost locked into it when placed.

I also added a tracer wire to each ditch, allowing the loops to be located in the future if needed.

 

So I am straight - you have six trenches at the end of the first 75 feet and each of the trenches is 7 feet deep, contains two pipes and is separated from the other trenches by 12 feet ?

 

Wing:
At the end of the 75 ft ditch, each loop has it own trench, 6 ft or more deep, 2 ft wide, Each trench is a loop. Each trench gives me 275 ft of loop ( 550 ft of pipe ). According to the loop link software I should be good. Distance between the trenches are 12 ft or more, I had plenty of space in the field and this made back filling much easier. Here is a rough drawing to show what Im doing. Hope that helps clarify.