how much heat would rise up a 1.5" pipe stuck in the ground and capped?

itr674 · 08-14-11, 11:26 PM

I was wondering if there is anyway to calculate how much heat would rise from a 1.5" pipe stuck in the ground 18", and 24" and with a cap on it?

Would there be any combination of things that could be done to keep the air inside that pipe above freezing in lets say 20 degrees F weather?

Daox · 08-15-11, 07:55 AM

Could you give us a bit more info on what you're trying to do?

A 1.5" pipe 24" deep won't be good for much at all. You need to go deeper and have a longer/larger pipe.

Ryland · 08-15-11, 08:57 AM

At least here, frost line is around 4 feet give or take, so a 2 foot pipe would freeze up solid top and bottom so to keep it warm you could install an electric heater in it, a small light bulb might be enough but I would think it would take 25 watts or more to make up for the heat losses.
Otherwise insulate the ground around it and insulate around the pipe.

itr674 · 08-15-11, 01:55 PM

Trying to come up with a cheaper way to have yard hydrants. Started to put in three but then started reading a lot about cross contamination. there are some that are sanitary but they are way to expensive.

twenty years ago I ran 1" pvc reduced it down to 3/4" and then ran it up insided three 2x4s screwed together. the center was cut out so the 3/4" pvc would fit inside. I think I used 8' lumber and buried sunk them 48" in the ground.

the pipe has never busted but I pretty sure it has frozen. took the cover off yesterday and it looks just like it did twenty years ago.

Any thinking about using 4" frost free sillcock (that's smallest I've been able to find) in and experimental up at the house so I can see if we can get water on freezing days, so trying to determine if heat rising from the ground could assist in keeping the pipe from freezing...

Daox · 08-15-11, 02:20 PM

If you aren't going to use them in winter, why not just blow them out with compressed air each fall or something like that?

Xringer · 08-15-11, 02:30 PM

Google says the frost line in North Carolina is 12"

It seems like some good insulation around the top 12" of pipe,
the geo-heat might not get let it get too cold.

Looking at the heat transfer, a metal pipe (copper is a good heat conductor),
would allow geo-heat from below the frost line, to be conducted to the surface.

If the pipe is well insulated above the surface and 12" below the surface,
the rate of geo-heat loss could be very slow,
Maybe allowing the top of the pipe to stay above freezing.

Seems like something you could test this winter.. If it gets real cold.

itr674 · 08-15-11, 03:19 PM

Xringer, geo-heat is what I'm hoping for...

Will get a couple of Woodford 101P faucets and will build one 2x4 post-box around it, insulate to 18" below and to top of post-box. Then will build another 2x4 post-box with no insulation, and do some testing this winter...

AC_Hacker · 08-15-11, 03:52 PM

Quote:

Originally Posted by itr674

...and do some testing this winter...

Testing is good!

-AC_Hacker

iamgeo · 08-15-11, 06:51 PM

I'm totally lost. What is it you are trying to make. A sprinkler system for the yard?

Daox · 08-15-11, 07:44 PM

Yard hydrant:

08-14-11, 11:26 PM	#1
itr674 Lurking Renovator Join Date: Jul 2011 Location: NC Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts	how much heat would rise up a 1.5" pipe stuck in the ground and capped? I was wondering if there is anyway to calculate how much heat would rise from a 1.5" pipe stuck in the ground 18", and 24" and with a cap on it? Would there be any combination of things that could be done to keep the air inside that pipe above freezing in lets say 20 degrees F weather? Last edited by itr674; 08-14-11 at 11:28 PM.. Reason: lets vs let

08-15-11, 07:55 AM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Could you give us a bit more info on what you're trying to do? A 1.5" pipe 24" deep won't be good for much at all. You need to go deeper and have a longer/larger pipe. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-15-11, 01:55 PM	#4
itr674 Lurking Renovator Join Date: Jul 2011 Location: NC Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts	Trying to come up with a cheaper way to have yard hydrants. Started to put in three but then started reading a lot about cross contamination. there are some that are sanitary but they are way to expensive. twenty years ago I ran 1" pvc reduced it down to 3/4" and then ran it up insided three 2x4s screwed together. the center was cut out so the 3/4" pvc would fit inside. I think I used 8' lumber and buried sunk them 48" in the ground. the pipe has never busted but I pretty sure it has frozen. took the cover off yesterday and it looks just like it did twenty years ago. Any thinking about using 4" frost free sillcock (that's smallest I've been able to find) in and experimental up at the house so I can see if we can get water on freezing days, so trying to determine if heat rising from the ground could assist in keeping the pipe from freezing... Last edited by itr674; 08-15-11 at 01:57 PM.. Reason: missed spelled sillcock...

08-15-11, 02:20 PM	#5
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	If you aren't going to use them in winter, why not just blow them out with compressed air each fall or something like that? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-15-11, 07:44 PM	#10
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Yard hydrant: __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

08-15-11, 08:57 AM	#3
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	At least here, frost line is around 4 feet give or take, so a 2 foot pipe would freeze up solid top and bottom so to keep it warm you could install an electric heater in it, a small light bulb might be enough but I would think it would take 25 watts or more to make up for the heat losses. Otherwise insulate the ground around it and insulate around the pipe.

08-15-11, 02:30 PM	#6
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Google says the frost line in North Carolina is 12" It seems like some good insulation around the top 12" of pipe, the geo-heat might not get let it get too cold. Looking at the heat transfer, a metal pipe (copper is a good heat conductor), would allow geo-heat from below the frost line, to be conducted to the surface. If the pipe is well insulated above the surface and 12" below the surface, the rate of geo-heat loss could be very slow, Maybe allowing the top of the pipe to stay above freezing. Seems like something you could test this winter.. If it gets real cold.

08-15-11, 03:19 PM	#7
itr674 Lurking Renovator Join Date: Jul 2011 Location: NC Posts: 16 Thanks: 0 Thanked 0 Times in 0 Posts	Xringer, geo-heat is what I'm hoping for... Will get a couple of Woodford 101P faucets and will build one 2x4 post-box around it, insulate to 18" below and to top of post-box. Then will build another 2x4 post-box with no insulation, and do some testing this winter...

08-15-11, 06:51 PM	#9
iamgeo Apprentice EcoRenovator Join Date: Aug 2010 Location: Lakehills, Tx Posts: 168 Thanks: 4 Thanked 10 Times in 9 Posts	I'm totally lost. What is it you are trying to make. A sprinkler system for the yard?