Trenched foam vs insulated pipe

Trenched foam vs insulated pipe

PostBy: Ted4 On: Wed Mar 12, 2014 6:37 pm

I need some input, I have a 50 ft run from my coal shed to my house. If I dig any deeper than 24" I will hit ledge stone. So I really have a shallow trench. My concern is this, I need to run 1 1/4" pair to house, but that doesn't give a whole lot of insulating in a5" pipe. I planned on foaming it myself but the more I read about closed cell foam, the more I read about it becoming slowly saturated when exposed to groundwater. Any and all opinions appreciated.
Ted4
 

Re: Trenched forum vs insulated pipe

PostBy: Ted4 On: Wed Mar 12, 2014 6:39 pm

Correction, ( Trenched foam), not forum!!!!!'
Ted4
 

Re: Trenched forum vs insulated pipe

PostBy: grumpy On: Wed Mar 12, 2014 6:41 pm

You can still fix the title..
grumpy
 

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Re: Trenched forum vs insulated pipe

PostBy: titleist1 On: Wed Mar 12, 2014 6:46 pm

I suppose you already looked at the cost and performance of the trench versus the logistics of moving/rebuilding the coal shed next to the house??
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Trenched forum vs insulated pipe

PostBy: Ted4 On: Wed Mar 12, 2014 7:11 pm

The shed can't be moved any closer, and my house is on a slab. Trenched foam would be relatively comparable to insulated pipe. My concern is whether the foam will be waterlogged after a while. Has anyone noticed a heat loss with systems that have been in for a few years, those who used foam in trench.
Ted4
 

Re: Trenched forum vs insulated pipe

PostBy: Yanche On: Wed Mar 12, 2014 10:40 pm

My advise would be to use a PVC conduit and push/or pull your insulated pipes thru them. I used a single run of PVC water well casing (8" dia., best I remember) as a conduit. Then insulated my supply and return pipes (1-1/2" copper) with closed cell foam insulation like that used on HVAC refrigerant lines. Where I needed to make a 90 deg turn I cut a PVC elbow into two pieces like a clam shell. Installed and soldered my pipes followed by gluing the PVC elbow back together. My PVC conduit is dry and should I need to service it, I can get to one end of it easily. My PVC conduit was schedule 80 PVC pipe, a much thicker pipe than needed. Suggest you use schedule 40 PVC or an even thinner wall pipe.
Yanche
 
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

Re: Trenched forum vs insulated pipe

PostBy: Wanna Bee On: Wed Mar 12, 2014 10:57 pm

Ever think about backfilling with 3/4" clean stone? Then keep the pipe up in the middle of the trench to allow water to drain.
Wanna Bee
 
Stove/Furnace Make: Grander Stove Co.
Stove/Furnace Model: Royal Bride

Re: Trenched forum vs insulated pipe

PostBy: Ted4 On: Wed Mar 12, 2014 11:13 pm

The problem is I have a low spot in the loop that I can't drain out without tearing up my patio and sidewalk, not to mention blacktop. I know a lot of guys use the drain pipe with the closed cell foam insulation filled solid. But that doesn't give a whole lot of insulating factor. I think the pipe OD is five inches. A friend used it and even at 3 ft deep it still melted the snow on top here in New York. Which is why I was maybe going for the DIY foam kits in the trench. Idk, I have to start as soon as snow is gone. I just would like to know how guys made out that sprayed in the foam. Of course all suggestions are appreciated.
Ted4
 

Re: Trenched forum vs insulated pipe

PostBy: Lu47Dan On: Wed Mar 12, 2014 11:34 pm

I replaced a set of lines run in a foam board box, the lines were laid in the box the lid placed on it and than backfilled. Worked alright for awhile, but it soon became waterlogged and lost lots of heat into the water and surrounding soil. I installed 6" PVC conduit with long radius sweeps. Than the 1" lines were replaced with a set of 1" twin closed cell foam insulated pex lines. They pulled through just fine.
The lines are buried 5' deep and the clay that came out of the bottom 2' of the ditch was put back into and compacted, the clay sealed out the water away from the conduit. No more racing stripes in the lawn.
One thing I did do was to install sump in the conduit to allow a sump pump to be let down into it to pump it out just in case the conduit would get flooded.
Dan.
Lu47Dan
 
Hand Fed Coal Stove: Sears circulator air tight stove.
Other Heating: Crown 115,000 BTU oil fired boiler(house) Weil Mclain 150,000BTU oil fired boiler(Shop)

Re: Trenched forum vs insulated pipe

PostBy: LoschStoker On: Wed Mar 12, 2014 11:45 pm

LoschStoker
 
Hand Fed Coal Stove: (New) Warm Morning 400A
Other Heating: Yukon Polar-Eagle II Multi Furnace
Stove/Furnace Make: Losch 350 130k BTU's
Stove/Furnace Model: DS Stoves 1500WH Short Lid

Re: Trenched foam vs insulated pipe

PostBy: nomorewood On: Thu Mar 13, 2014 7:42 am

I have a central boiler wood furnace. I installed their system and never had any problems. Go to their web site and check out the system they sell. It is expensive but it does work. Good luck
nomorewood
 
Stoker Coal Boiler: AA 130
Coal Size/Type: Pea
Other Heating: Oil

Re: Trenched foam vs insulated pipe

PostBy: katman On: Thu Mar 13, 2014 8:50 am

I went through this excersize about three years ago when trying to decide what to do when running about 100 feet of 1 1/4 inch pipes from my barn to the house. Get your pen and paper out and cost out the va. This will help you make the decision. And, regarless of the input you get from everyone hear, the costs vary widely by region so check with your local suppliers. That includes the cost to put foam in the trench. You can by kits and do it yourself or hire someone to spray after you have done all the grunt work laying the pipe. Foam costs vary quite a bit, but make sure you compare the same types of foam and similar applications.

I looked at the approach Yanche used, which sounded ideal to me. Turned out to be the most expensive, by far, for materials, regardless of whether I used copper or iron pipe, Schedule 40 or thin-walled sewer pipe. I checked several different places for materials prices, and even with contractor pricing I couldn't get acceptable numbers. Plus this would have been the most labor intensive and probably required the most time for me to do the install myself.

Foam in trench also would have been labor intensive for the pipe work if I used copper or iron pipe, but pricing wasn't too bad for 1 1/4 oxygen barrier pex. If you consider this option make sure you can get the pex because I did see some supply shortages when I was sourcing the long rolls I wanted so I would have no underground splices. The quotes I received for the foam from local contractors varied considerably, but all made this an expensive option too. I looked at the kits. Doing all the work myself, including the foam, made this option competitive.

The third option, which I ended up going with, was 1 1/4 thermapex purchased from one of the local companies that does installs for one of the outdoor wood boiler companies. The pipe was expensive, but it turned out, with fittings to connect to 1 1/4 copper (which is what I ran inside the barn to connect to my boiler), was marginally less than the foam in trench option. A major benefit was the install was quick and easy. Dug my trench and put the pipe into it, running one end into the barn and the other into the house. Filled the trench, made my inside connections and lit my boiler. The depth of my trench averages about 30 inches. In a few places where I had to skirt the corner of my septic tank and footings for my deck poles I'm probably not much more than a foot deep. But I have noticed no snow melt on the surface, even in the shallow areas. If you look at this option keep in mind that you cannot make a tight turn so a straight run is ideal. Also, do it when it is warm out. Handling a 100 foot length of this insulated pipe when it is cold is challenging if you don't have help.

The thermapex is a nice product and there are other similar products out there. I was surprised that the cost to use this option turned out to be the least, not counting the labor savings. Materials may be cheaper in your area, or the thermapex could be more expensive. But this is the solution that worked for me and I have no worries about leaks or saturated foam.

House is warm and wife is happy. Oil boiler inside the house feels neglected.
katman
 
Hot Air Coal Stoker Stove: Harman Magnum
Other Heating: Harman PB 105 Pellet Boiler

Re: Trenched foam vs insulated pipe

PostBy: titleist1 On: Thu Mar 13, 2014 9:04 am

katman...have you ever measured temps at the boiler and at the basement to see what the difference is, if any, over the underground run?
titleist1
 
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite

Re: Trenched foam vs insulated pipe

PostBy: franksnbeans On: Thu Mar 13, 2014 9:17 am

With my underground run which is about 50 feet I lose about 4 degrees. Also my trench is only 18 inches deep. There is absolutely no snow melt at all.
franksnbeans
 
Stoker Coal Boiler: AA 130
Coal Size/Type: Pea

Re: Trenched foam vs insulated pipe

PostBy: Ted4 On: Thu Mar 13, 2014 9:41 am

Yeah, I'm surprised my friend has snowmelt at 3 ft down myself. He has a wood boiler and runs at least 100 ft away. He's losing a lot of heat for some reason. I have radiant in slab so my water temp is already cut way down. Nothing like coming in out of the cold and feeling those warm floors. But the oil is killing me. I bought this boiler from someone on this site about four years ago and finally got the shed up before winter. The thousands I've thrown away on oil is sickening.
Ted4
 

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