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geointerest User is Offline

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10/08/2009 10:23 PM
Hi, I was would like to install an eight or a twelve pipe horizontal loop system on a four ton house I am doing. I have had igshpa training that seem to contradict some of the other training I have recieved. I was told that reduced headers are necessary for purging purposes, since a lot of purge pumps don't have enough capacity and without a reduced header air becomes trapped in the header effectively "shutting down" that last loop. I have seen pre fab headers for up to six pipe headers with no reducing though. I am eager for information on this and would appreciate any info from experienced installers out there who know what they are talking about. Joe?? Thanks

waterpirate User is Offline

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10/09/2009 7:29 AM
Reducing the header sizefor proper purging is not really the issue, a bigger purge pump will take care of that. Balancing the flow is the trick. For a horizantal system this easily achieved by paying attention to pipe lengths and installing some balancing valves in the house. Hope this helps Eric Sackett weberwelldrilling.com

Eric Sackett WeberWellDrilling.com

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10/09/2009 8:58 PM
I'm not a closed loop guru, but I second Eric's remarks. Every now and then I read hints / posts suggesting that system circ pump ought to somehow be able to handle purging and that is most assuredly false. A purge pump is typically a much bigger (on the order of x10 more powerful) pump temporarily interconnected to greatly increase water flow rates through the loops to capture and carry to atmosphere any trapped air bubbles.

Without data, you only have an opinion.

geodean

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10/10/2009 7:40 AM
Reducing headers are a good idea. We always install them. There is no good reason to eliminate them, yet good reasons to build them in. If the supply lines are 2" or more and your loop lines are 1" or less, and you don't do a reducing header, you will probably never purge all of the air no matter how big your purge pump.

Dewayne Dean PalaceGeothermal.com Why settle for 90% when you can have 400% We heat and cool with dirt! visit- http://welserver.com/WEL0114/- to see my system

geodean

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10/10/2009 7:44 AM
Posted By geointerest on 10/08/2009 10:23 PM I have seen pre fab headers for up to six pipe headers with no reducing though. Who makes prefab non-reducing headers?

Dewayne Dean PalaceGeothermal.com Why settle for 90% when you can have 400% We heat and cool with dirt! visit- http://welserver.com/WEL0114/- to see my system

Dan CGD

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10/12/2009 12:09 AM
The other conern I would have is with a 8 to 12 pipe system, make sure you keep an eye on flow for turbulent numbers. This is easy enough to do by having 4 individual flow paths using 3/4" pipe. The reducing headers would be fairly simple and you could use a short header, or a reverse return. If you do a short header, just follow as Eric states above and keep pipe lengths to each as close as possible to allow for system to be self balancing. Dan

joe.ami

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10/12/2009 6:19 AM
Number of pipes caught my eye as well and makes me question design. equal lengths, reverse return, reducing headers are all good practice, but loops are much more forgiving than they sound. You could do none of these things and enjoy success anyway with a good flush. J

Just a Mechanic; Geothermal; Savings Underfoot

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