Hello: Looking at installing a Horizontal Loop system, 4 x 600ft loops with manifold inside the basement. I have no issues with space and been exploring concepts a bit on install. Soil is mostly red clay, some sandstone. Questions: Option 1: Long trench, 16" bucket, 6 ft deep, two pipes ( 16" apart ) and each trench spaced 5 ft from the other three trenches. One loop in a trench. ( out and back ) Option 2: Long trench, 32" wide, 6 ft deep, two pipes ( 32" apart ) and trench 10 ft from other three. One loop in a trench. ( out and back ) Is there any real "efficiency" gain by using the greater separation between the pipes? My installer suggested changing to 4 x 700 ft loops as a added "extra buffer" for exchange. Seems like a small investment for a larger "heat sink" Thoughts are appreciated, I am trying to learn as I go along on this project. Randy
Check out a website called Loops Link. It is free and allows you to input all your info (unit model, manual J load calc, etc) then input various loop layouts and see estimated average, minimum and maximum EWT. Common sense and the program said that having each loop in separate trenches (out and back in separate trenches) 8' apart was the best for keeping loop temps up. Albeit with more excavation. I lowered that by hiring a large trencher to make 8 5-6' deep 10" wide trenches for 4 loops 700' each. What size heat pump are you putting in?
Thanks Eric. I am checking the loops link now. HP is 3.5 T. As for the trenches, I will be doing the digging ( Backhoe and a recently obtained 24" bucket ) so the digging is not a issue for me. In the reading on the design concepts, it seems to be a trade off on size of loop and the pumping needed. In a commercial side, I can see the expense versus result issues, but as a curious engineering type, I am learning. Thank you for responding. I hope to begin installing soon as my air exchange unit has died.
With my 4 - 700' loops, a grundfoss 2699 pump delivers 9-10 gpm on medium speed. Which is less than 200 watts of power. I have been very pleased with my design.
Worked with the software, very interesting. I adjusted loop length and spacing, so seems like 2 pipe laying, 2 ft trench, 12 ft space will be my route. I have no issue with the space, will actually make install easier. Even explored stepping up again to a 800 ft pipe, but the gain did not seem worth it, and probably overkill.
With you on the expense vs return thing. Most people don't have basically unlimited space like I did. Total expense not counting my labor was less than $15000. That included all new ductwork in house. I spent 7 days on actual install plus probably 5 days on research and design (just ask my wife). My EWT barely dipped below 40* this winter, which is about what Loop Link predicted. Good luck and have fun. I have a thread about my build on this forum
Here it is. https://www.geoexchange.org/forum/threads/starting-diy-horizontal-closed-loop-in-ne-ohio.7552/
Read were you didnt need the two pumps.... Im trying to decide on the flow center now, we have almost the same setup, making me rethink the two pump issue. Thoughts?
I would say no. Even if you would have slightly less flow than mine, the HP won't know it. Performance difference would not be measurable except under laboratory conditions.
Did you remove the second pump and plate over yours? And I assume the relay you mentioned is switching your pump from med to hi and controlled by the low and high stage on the hp when it runs? Now we are back to my world of electronics and electrical......
I didn't remove it yet, but am planning to. And yes that is what I did. A 24VAC SPDT relay and a continuity tester on the pump motor switch to figure out what the switch does is all it takes.
