Underground lines - not the place to skimp!

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The key word here is "infiltration". Like your house, it doesn't matter how much you insulate it, if cold air can find it's way in you won't be pleased with the loss of heat. Water infiltration on your pipe is the worst. The water will fill the drainage pipe and then soak the little wrapped cellulose/reflective material. Now the hot water has to pass by all of this and the old saying of heat goes to cold is true. The water wants to become warm so it sucks the BTU right out of the pipe. As I wrote earlier, I ran my line 150 feet from the boiler to the house and lost 40 degrees going in and another 40 going back, not even accounting for the load from the house or the hot water usage (Potable/Domestic). The "Wrapped" pipe leaves plenty of air space around it, inside the drainage pipe. The micro cell foam looks like a spongy insulation and I don't know that much about it although I would say if water got in there, it might seep down to the pex lines. The stuff I'm using (See below) is hard foam. Even if I got a pinhole in the black outside piping, there is no where for the water to go. It would stay on the outside of the hot water lines.
I don't know where you are located but you could contact the mfg to see if you can get some in you r neck of the woods.

Urecon (Florida)
4185 South U.S. Highway 1
Suite 102
Rockledge, Florida 32955

T: 321.638.2364
F: 321.638.2371
E: [email protected]
 

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I'm on the Canadian border, so it's COLD! 20f yest... The pipe pictured is from Florida??? What do they know from heat? they do have a hi water table tho...

So it would seem that this's what you're using? where's you get it? a local supplier? Shipped especially for you? What's the heat loss? Price p ft?
 
Canada
Urecon (Quebec)*
1800 Ave. Bedard
St. Lazare-de-Vaudreuil, Quebec
J7T 2G4

T: 450.455.0961
F: 450.455.0350
E: [email protected] Urecon (Alberta)*
5010 - 43rd. Avenue,
P.O. Box 210
Calmar, Alberta
T0C 0V0

T: 780.985.3636
F: 780.985.2466
E: [email protected]
* manufacturing facility * manufacturing facility
Urecon (Ontario)
115 George Street, Suite 625
Oakville, Ontario
L6J 0A2

T: 905.257.3797
F: 450.455.0350
E: [email protected] Urecon (Quebec)*
48 rue Séguin
Rigaud, Quebec
J0P 1P0

T:(450) 451-6781
F:(450) 451-0132
E: [email protected]
* manufacturing facility (field applied insulation fabrication)
Urecon (Newfoundland)
3 Bluebell Bend
Portugal Cove / St. Philips, Newfoundland
A1M 2G5

T: 709.895.8100
F: 709.895-8101
E: [email protected]
 
It's 19f here right now. I'll get my heat exchanger hooked up Monday so I should be off oil(again) very soon. Good luck with the project.
 
I'm thinking this is the Cadillac of pipe. You'll pay for it. I bought mine in Hoosick NY. I bought 1 1/4" ID for $18 / Foot. The connectors are special order and will run you ~$62 / per connector. Canada was going to ship them for $311 ( for 4), but I instead rammed an 5" x 1" black nipple pipe down it about 4 inches. I will know Monday how that works. Stay tuned.
 
mhvfd said:
The key word here is "infiltration". Like your house, it doesn't matter how much you insulate it, if cold air can find it's way in you won't be pleased with the loss of heat. Water infiltration on your pipe is the worst. The water will fill the drainage pipe and then soak the little wrapped cellulose/reflective material. Now the hot water has to pass by all of this and the old saying of heat goes to cold is true. The water wants to become warm so it sucks the BTU right out of the pipe. As I wrote earlier, I ran my line 150 feet from the boiler to the house and lost 40 degrees going in and another 40 going back, not even accounting for the load from the house or the hot water usage (Potable/Domestic). The "Wrapped" pipe leaves plenty of air space around it, inside the drainage pipe. The micro cell foam looks like a spongy insulation and I don't know that much about it although I would say if water got in there, it might seep down to the pex lines. The stuff I'm using (See below) is hard foam. Even if I got a pinhole in the black outside piping, there is no where for the water to go. It would stay on the outside of the hot water lines.
I don't know where you are located but you could contact the mfg to see if you can get some in you r neck of the woods.

Urecon (Florida)
4185 South U.S. Highway 1
Suite 102
Rockledge, Florida 32955

T: 321.638.2364
F: 321.638.2371
E: [email protected]

This looks like good stuff kind of like Thermopex. Much better than any of that wrapped tin foil stuff. Probably $15 a foot but if you don't want to foam in trench this would be the way to go.
 
Be careful with the "foil insulation wrapped pex in black corrugated pipe" like they sell on ebay, a buddy of mine just had to dig up his yard as his was leaking water in his basement a month after he installed it, probably some kind of manufacturing defect in the pipe is my guess... like the title of this thread says, not the place to skimp.
 
Sorry, I see no other format available.
Any one with experience on this product?
SK
 
I just finished w/my install on Monday, using the Urecon "Logstor" pipe. I'm running 90 feet of 1 1/4" ID from my Sequoyah E3400 to a 24" x 24" water to air exchanger. I believe it's a 240,000 or 250,000 BTU exchanger.
The temp on my boiler is set for 190f with a 5 degree low point for reactivation of the fan. I'm using a Wilostar 30 which I think is running at ~9-10 GPM and it's pumping heated water 24/7 thru the exchanger. I have temp gauges on the exchanger and it appears I'm losing zero degrees on the supply side. When the Furnace fan kicks in, it looks like the delta is ~10-12 degrees, but it's hard to say since the gauges have a dial on them and I have no clue how accurate they are. I do know that with the other pipe (double wrapped) I used, the loss was incredible and I had a radiant path all winter to my wood shed. Snow is expected today and for the next week so I should get a better feel for how the system is working.
I will tell you this, the wife isn't bitching about the house being cold as I've set the thermostat at 69f in the hall way downstairs. By the time it gets to the office upstairs, it quite a few degrees higher than 69f and she's very happy. I'll update as the winter draws thru and bases on the wood I've used so far, I'm looking at burning 8-10 cords versus the 20 cords I had to cut and store. Sounds like a better Xmas already.
 

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I added the rest of the pics....let me know if anybody has any questions, suggestions, etc.
 

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When I relocated my gassifier from the house to the new boiler room in 2008, I used Insul-Seal pipe. One of the super-posters here, a contractor I believe, stated he uses only this method and I followed his lead with no regrets. I am flowing 400 feet round trip and have only 1 degree of heat loss, and that is a stretch, as I am using calibrated instrumentation and actually show less than a degree. Very expensive up front cost, but well worth it for the long run.

http://www.insulseal.com/
 

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CORVAIRWILD said:
I was thinking to do the same thing with my future Waste Oil Boiler. It would run under a large driveway and truck turnaround, so it'll be placed in 8 or 10" corrugated sewer pipe. I wonder if plastic would still be needed?

Just to let you know. I'm using 1'' pex with 1/2'' slip-cover insulation
wrapped with duct tape pushed through 3'' pvc plastic pipe.
Seems to lose about 2 deg. on a 90' run.
 
This foaming in place method seems like a great way to go, especially if you are planning on having multiple pairs of PEX lines. I have a couple questions about it though. I assume that you aren't relying on the polyethylene plastic sheeting to keep water out, but more to keep most of the dirt away from the foam and so that the foam can be wrapped up in a neater, more circular package as the foam is curing? My backhoe has a 24" bucket which is far too wide for doing the foam in place method without first narrowing the trench where the foam will go. Since I will also be installing multiple electrical conduits in the same trench, does it seem like a good idea to make a smaller trough to one side of my trench using 2" of XPS foam sheathing on the bottom and on two sides? XPS foam sheathing (R-5 per inch) costs about $0.44 per board foot, making it a slightly better value than the spray foam (R-7 and about $1.00 per board foot). I'm thinking that the XPS will butt up against one wall of the trench and then I will backfill over my electrical conduits with enough sand to hold the other XPS wall in place, maybe putting an occasional spreader between the two XPS walls to keep the sand from pushing the wall in prior to adding spray foam. I can still put the polyethylene sheeting under my XPS trough and wrap it over the top of the expanding spray foam. Does that all sound like a good plan in my case? If you were to do it this way, would you cap off the trough with 2" of XPS on top (with some temporary weights on top of the XPS) after spraying in the foam, or would you just let the spray foam expand out the top of the trough and wrap the plastic over it?
 
What I did was dig my trench about 4' deep with an excavater and then I ran my electrical conduit on the bottom of the trench. On top of that, I draped my 8' wide plastic sheet in the trench like a deep 'U', securing the ends to the top of the trench temporarily. That created a nice sized trough for the pex and foam. I laid the pex in, then spray framed in place while lifting the foam as I went. Once the foam was hard, I tucked the plastic around the foam and I backfired the next day.
 
I bought thermopex 12.50/ft for 2 1" pipes inside, I have 85' and can't find any heat loss for the run, manufacturer claims 1 degree loss for each 100'. I spent over 1 grand but that was money well spent.
 
Pete, Yes, I used the plastic sheeting just to keep the process clean. After the foam is blown it serves no purpose. I just laid it up on the sides of the trench as shown in the pics and put rocks on it every 8-10'. Ok.... can't spend a lot of time on this but a quick look shows XPS thermal conductivity at .027-.03. Urethane foam at .021. Do some quick research on line like I just did and compare Heat Transfer Coefficient. Bottom line using the spray polyurethane is a better insulator so using the sheet stuff is a waste of time and money. No need for multiple trenches, since the electrical conduit doesn't care about temperature, you can do what I did, just lay on top of the cured foam and cover with dirt. So in summary, if you compare the material properties of what you intend to use, you'll most likely find the XPS is a poorer insulator (or a better heat transfer material) than the spray, closed cell, polyurethane.

BTW, my water round trip distance is about 440'. I am routinely seeing a 2*F delta from my AZEL temp sensor in the boiler room where my water enters my 1 1/4" Pex. After prolonged idle... yeah bad but.... I frequently see the deltaT close to less than 1*F (an unbelievely sometime less than 1*F). That is an amazing .22*F/100' of run. In review, my contractor that dug up my first "go cheap" attempt using those insulation sleeves had a 12" wide bucket. So my pex is in a block about 12"W x 10"deep. Far more than most need but it was a byproduct of carefully digging up my first attempt so I could reuse my pex (mission accomplished). If I knew how I'd post pics of my AZEL digital display to so the temps to document what I'm asserting. There ain't no way the off the shelf stuff can match my 12"x10" foam brick that I had sprayed. My underground is about 180' and I paid $700 or $800 to do the trench. All insulation done in about 30-40 minutes then recovered with dirt. I would guess the cost/performance crossover point for spraying in place vs the Thermopex type stuff is maybe when the underground gets in the 30'-40' range. At shorter underground distances the losses using a Thermopex type product probably wouldn't justify the expense of a foam contractor's minimum charge.
 
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Thanks Tennman. I didn't say that XPS was a better insulator than the spray foam, but that it was a better value from an insulating standpoint. 2" of XPS is R-10 and costs about $0.95 per square foot. To achieve an R-10 value with the spray foam you would need a layer about 1-7/16" thick, which would cost about $1.43 per square foot if you are using Tigerfoam. Maybe by hiring a spray foam contractor you can have it done for less than it would cost with Tigerfoam. In terms of labor, you are absolutely right that slinging plastic sheeting into a trench, secured on the sides with rocks (which I have plenty of here in NH) is much easier than creating an XPS trough. Also the foam blown into the plastic sling would result in a more a cylindrical block of foam, which would provide more constant insulating value from all directions than the squared off block with the XPS. One thing that I like about the XPS trough filled with spray foam though is that it is easier to judge how much spray foam you are going through. If you have a trough made out of 2" XPS that has an 8" x 8" open trough, you can figure out how much spray foam you will need. I would hate to buy the $600 Tigerfoam setup to do my 100' run, only to find that I was spraying too much foam and came up 10' short in my trench. I guess if you go with a spray foam contractor you don't have that potential problem.

I wasn't planning on digging multiple trenches. A 24" wide trench is more than adequate for everything that will be going underground.