How close is too close for deep boreholes?
Last Post 12 Nov 2014 01:58 AM by docjenser. 24 Replies.
Printer Friendly
Sort:
PrevPrev NextNext
You are not authorized to post a reply.
Page 2 of 2 << < 12
Author Messages
joe.amiUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:4377
Avatar

--
11 Nov 2014 08:28 AM
Even if the seperation of the tails was 1.5 to 3' at the end of the vertical loops, the average seperation would be much greater. i.e. we start 16' apart and end at 3' average distance will likely be at least 6.5' and likely greater as the path isn't likely truley diagonal , it is more likely paralell with the occasional jog.
Also depending on the number of loops there may be benefit elsewhere due to greater seperation from other loops.
I think the estimation of 18-25% impact is high.
Joe Hardin
www.amicontracting.com
We Dig Comfort!
www.doityourselfgeothermal.com
Dig Your Own Comfort!
docjenserUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1400

--
11 Nov 2014 09:39 AM
Posted By Yonder on 10 Nov 2014 06:02 PM
Ah sorry, I read him as saying that eventually the boreholes came within 3' of each other, and I assumed that his percentage was based off of an assumption of when the boreholes would get that close together. I would imagine that the boreholes would remain 15' away for at least a hundred feet before starting to wander off near each other, and they would probably approach each other fairly gradually.


For the purpose of this discussion, your loop field should be fine, the 14.5' instead of 16' distance has no significant impact on your performance.
www.buffalogeothermalheating.com
jonrUser is Offline
Senior Member
Senior Member
Send Private Message
Posts:5341

--
11 Nov 2014 10:45 AM
As I said, "unlikely" - consider my numbers (based on a double jog) a near worse case example serving only to illustrate that "fraction of a percent" isn't always correct when you only know surface distance. On the other hand, as geodean's picture shows, unlikely, worse-case events can happen and it's often good to know what they are.

With two holes, deviation from straight is just as likely to improve performance. So the typical/likely case = 0% impact.

I'm pretty sure that Yonder has moved from concerned to interested in the theories.

The numbers are straight from the graph in the reference.
YonderUser is Offline
New Member
New Member
Send Private Message
Posts:14

--
11 Nov 2014 11:43 AM
Oh yeah, sorry, my concerns on the 14'5" separation between the boreholes have been alleviated. I'm still annoyed that they drillers didn't do it to spec, but I'm not concerned about the capability of my unit (although I will be tracking my incoming water temp to look for signs of oversaturation, it looks like I'm fine as long as incoming water temperature stays above 30 F from discussions I've seen skipping around this forum). My last posts were just out of interest of the intersecting boreholes.
docjenserUser is Offline
Veteran Member
Veteran Member
Send Private Message
Posts:1400

--
12 Nov 2014 01:58 AM
Posted By jonr on 11 Nov 2014 10:45 AM
As I said, "unlikely" - consider my numbers (based on a double jog) a near worse case example serving only to illustrate that "fraction of a percent" isn't always correct when you only know surface distance. On the other hand, as geodean's picture shows, unlikely, worse-case events can happen and it's often good to know what they are.

With two holes, deviation from straight is just as likely to improve performance. Ie, typical/likely case = 0% impact.

I'm pretty sure that Yonder has moved from concerned to interested in the theories.

The numbers are straight from the graph in the reference.


Now keep in mind that the numbers, formulas and algorithms the tables and software programs are using are derived from certain field measures. How did people know that the pipes did not deviated from straight when they originally established those performance numbers?
www.buffalogeothermalheating.com
You are not authorized to post a reply.
Page 2 of 2 << < 12


Active Forums 4.1
Membership Membership: Latest New User Latest: hudson2000 New Today New Today: 2 New Yesterday New Yesterday: 0 User Count Overall: 34707
People Online People Online: Visitors Visitors: 152 Members Members: 2 Total Total: 154
Copyright 2011 by BuildCentral, Inc.   Terms Of Use  Privacy Statement