Help, vertical or horizontal?

[KaraS]

Hi, we have decided to replace our oil and heat pump / AC with geo. we have 4 quotes and have been working on the design for months. I need to know if we should go with vertical closed loop or horizontal. Please help me decide, i want the best system. A little background, we live in MD on 5 acres cleared land. We need a 5 ton system (split, 3 down 2 up). We have a 300 ft well already that only supplies outside after for outside of the home, we can convert this well and drill a second one, biggest problem being that it's 345 feet away from the house so the trenching costs back to the house have to be considered. So we have quotes for both vertical Converting our well and horizontal, but which will perform better?? I need help as I've read good and bad about both and don't know what to believe.
Thanks!
Kara

[SkyHeating]

I hate to say it but that will all depend on your location. We would need more info on the well to find out. Typically the well will perform better but they often come at a much higher cost. A well often doesn't have to pump as hard(electric savings) because the well is 300' away and 50' down for a total of 350' often a close loop system has 800' circuits so more pumping. In my area they don't really let us do open loop systems because our Department of Environmental Quality doesn't allow it very often, to many hoops to jump through.

[crash11]

Yeah without knowing a lot of details, it basically comes down to payback time. The vertical wells are more efficient, and they will eventually payback over some period of time. The question is, how much time? If you plan on using this geothermal system for a long time, then I'd probably invest in the vertical wells. Again though....there are a lot of unknowns. These are just general statements.

I installed a horizontal loop because I was able to do the excavating reasonably cheap, and I fused the pipe together myself. Also, we didn't plan on living in the house more than 10 years. However, I'm almost positive it's not as efficient because I get rather large swings in EWT, and when I used to have open loop drawing from quite deep the EWT was far more stable.

[kdean1]

Another thing to consider is the quality of the water in your well if you are thinking of an open loop. The potential issue is how much sediment may circulate through your system. Most equipment manufacturers recommend a closed loop in order to reduce the erosion inside the heat exchanger.

Vertical wells perform better than horizontal wells at the outset because the tubing is in full contact with the earth,provided the well hole was pumped full at installation. Horizontal loops take time for the ground to completely settle to achieve complete contact.
Have you considered new wells closer to your home to reduce the disturbance to your property?

As others have suggested, you need a good soil analysis and system design for the best results.

[Awinterfield]

Open loop and closed loop are both good, but you have to look and water quality, GMP that the well produces. Like the others have said there are additional costs involved in open loop, ie. drilling cost, and additional equipment cost. If you have good soil and room horizontal trenching can be less expensive, yes the is more pipe but drilling can be very costly.