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Old 05-22-11, 02:31 PM   #13
AC_Hacker
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Quote:
Originally Posted by Blauhung View Post
Oh and for 1 ton of heat transfer in my area I will need 200' of pipe in place under 10' of ground so right now I will probably aim for 5 or so 50' holes
How well do you know the heating requirements for your house?

There are a couple of ways you can do this...

One way is to look at the amount of fuel you consumed over previous winters and average it on a per month basis. Then design for your worst month. If you don't have your bills, the company that sold you your fuel still has that info. I'm not so sure if the fuel company will give you that info for previous owners.

The other way is to do a "Manual-J" type of analysis. This method models the insulation type and window type and surface areas and your inside preferred temperature and the seasonal temperature for your particular location and comes up with an overall heat loss.

I don't currently have Excel installed on my computer, but I have found what appears to be Manual-J in a downloadable Excel form.


Additionally, I have found a Manual-J training video here.

And also, Watts Radiant has a free software tool called RadiantWorks that will do a heat loss calculation for you.

The heat load (AKA: heat loss) calculation is pretty important and I have used all of the approaches shown above, and in addition, I have done real time worst-case severe winter weather monitoring of my BTU requirements using electric heaters and Kill-a-Watt meters. I have then compared all of my approaches to get a good idea of how much heat I will actually need.

* * * * *

When you've got your drilling rig working, and have found how deep you can go, you'll probably want to do a heat transfer test (that test hole will become part of your loop field) to determine thermal transfer for your actual site . Your estimate of 200 ft/12,000 BTU is probably really close, but by going through the heat transfer test steps, you'll have the opportunity to familiarize yourself with HDPE welding, and hole grouting, and you'll be more assured that you're proceeding along the right path because your heat transfer test will give you the information you need to combine with your house heat loss information, to know exactly what the minimum loop size must be.

-AC_Hacker
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Last edited by AC_Hacker; 05-22-11 at 02:33 PM..
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