Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: flashpnt on September 25, 2014, 01:36:08 PM
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OK stove to the house is under 20 ft , just cant make my self buy $1000 in hose for a 20 ft run.
thinking about using 4" pvc with my 3 runs of pex inside . drill a 1/16 hole every 2 ft in the 4" pipe .
Take great stuff foam in the can insert hose into the 1/16 hole and squirt it full then move to next hole ect.
after it drys use silicone oner the holes to make sure the foam does not collect water. What do ya thank ? comments welcome.
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i dont think the lines cost that much.about 300 for 20 foot you do not need insulated line on inside
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OK stove to the house is under 20 ft , just cant make my self buy $1000 in hose for a 20 ft run.
thinking about using 4" pvc with my 3 runs of pex inside . drill a 1/16 hole every 2 ft in the 4" pipe .
Take great stuff foam in the can insert hose into the 1/16 hole and squirt it full then move to next hole ect.
after it drys use silicone oner the holes to make sure the foam does not collect water. What do ya thank ? comments welcome.
First you'll have a hard time keeping those lines centered in the PVC, not sure but if I did attempt that, I think it's possible to get closed cell foam in a can, not sure what Great Stuff is. Might take a lot of cans before you're done.
20 foot of Logstor even at $15/foot is only $300. Think it's more like in the $12.50/foot range.
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OK stove to the house is under 20 ft , just cant make my self buy $1000 in hose for a 20 ft run.
thinking about using 4" pvc with my 3 runs of pex inside . drill a 1/16 hole every 2 ft in the 4" pipe .
Take great stuff foam in the can insert hose into the 1/16 hole and squirt it full then move to next hole ect.
after it drys use silicone oner the holes to make sure the foam does not collect water. What do ya thank ? comments welcome.
There is stuff out there at 6-7 bucks a foot that will do a better job than PVC with holes drilled in it and stuff-it. Besides, cost of materials and time with your plan will exceed cost of a 20 foot run. I did 200 feet for 2100 in Logstor and it loses only 1 degree.
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Foam in a can is open cell foam, if you use it as you intend to do, open cell isn't water resistant, and with drilling holes in the pvc, your creating a drain tile that will hold and absorb water, totally defeating your process completely.
I'd recommend the insulated pipe such as logstor but if your determined to use pvc, take some boards and drill holes in them, cut them into a circle to fit into the pvc and use those to hold the lines centered, drill your holes and before your done, wrap the holes in the pvc up completely with tile tape, not duct tape or anything else, tile tape is water resistant and won't rot or decay under ground or let water into the holes in the line. Glue the pvc together very well and then wrap those couplers in tile tape as well. You'll also need at least six inch pvc, not four inch because open cell foam has half the insulation value per inch as closed cell foam, or if you use four inch pvc, you line has half the insulation as logstor does. Where it comes up by the furnace, either have it come directly into the insulation/protected area of the furnace or if it has to come up outside, make sure you have an angle fitting on the line, to keep water and moisture out of the line, open cell won't shed water if you have the opening facing upwards and rain gets into it. With all the costs involved I can't imagine its cheaper than logstor, not to mention your time involved. Before I'd do that I'd buy the five wrap line that badger pipe sells but that's just me.
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OK bad ideal thanks guys
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How about hiring an actual spray foam guy to come out and shoot your 20' section with closed foam, or course you would probably have to build a form to hold the pipes out of a hard foam board or something like that
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How about hiring an actual spray foam guy to come out and shoot your 20' section with closed foam, or course you would probably have to build a form to hold the pipes out of a hard foam board or something like that
This is what I did, I had about 180' of trench. It ended up costing me about $5.60 a foot for the spray foam. I didn't have to build any type of form. The spray foam guy simply picked up the pex, sprayed about 3"-4" underneath, then laid the pex back down and sprayed 3"-4" on top. Worked really well and went pretty quickly.
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Spraying your own underground lines seems to be all the rage over to Hearth.com, I even have an account over there, spent several nights reading and haven't ever been back. To be polite, they are just a tad bit anal over there.
For the time involved and the width of the trench you have to dig, in that short of run just buy the three wrap from Z-supply and be done with it, or splurge and go wit the five wrap.
A spray foam guy might have a minimum for a job and your twenty foot might not cover it.
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X2 on the trench spray foam. I have a 75 foot run and this is what I did as well. I also did not put a form in the ground. I simply hand dug the trench the width of my shovel. Then I placed a piece of cheap styrofoam on th bottom of the trench just to have something to spray the foam against. Spray foam guy sprayed the bottom then dropped the lines on too and sprayed again. Cost me $500 to spray the trench then spray the boiler. Been 3 seasons since I did it and haven't had any problems.
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I'd be somewhat concerned of water infiltrating the spray-foam over time. Did you guys put anything in place to protect it from potential ground water soaking it? I'm not criticizing, just curious. Thanks, Roger
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I'd second the five wrap idea myself, drain tile, solid not perfereated is water tight, also bug and worm tight, gophers and mice will eat into it if they are inclined to do so. Tile has been around for mearly 50 years now, has undergone dozens of forumula change to get it to where it is today to hold up for the long term, no foam has ever undergone testing of that use ever from what I've been told and understand, not saying its a bad product to bury uncovered, just saying its not been tested being buried uncovered or has decades of testing and studies behind it, not to mention forumla changes to meet and match that application.
Also, its a one time application, one time use, I've dug my logstor up twice and relocated the funace twice, might end up doing a third time shortly and every time the logstor has been fine, we just hand dig near the line and uncover it and move it to its new location and lay it to grade and put dirt back over it again.
Some may ask why it was moved, simple, we moved and I took it with us, and then we had a water leak, along with a broken tile line that needed repair so we moved it slightly out of the way to do the repairs and then put it back in place, next move might be once a building is torn down to pour a new pad for it making moving around the furnace much nicer and for snow removal to be much easier.
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I'd be somewhat concerned of water infiltrating the spray-foam over time. Did you guys put anything in place to protect it from potential ground water soaking it? I'm not criticizing, just curious. Thanks, Roger
The spray foam is supposed to be waterproof at 1 3/4" thick. There is a minimum 2 1/2" to 3" around my pipes. I still had some concern so for an extra layer of protection I placed my lines on top a 4" perforated pipe and 6" clean stone, and then backfilled to the top of foam with more clean stone, this way there should never be standing water around the foam. With stone, perf. pipe, pex and spray foam it came to about $8.50 per foot. This was less than half the cost of Logstor or any other pre-insulated closed cell product I could find. Also, because I ran my return line halfway back to the OWB in the same trench as the supply but then bent it 90 deg, ran it into my garage and then back to the trench, the pre-insulated products wouldn't have worked.
It may be a little anal but it wasn't much more expensive then the 3 and 5 wrapped products, and I have read a lot of horror stories about water infiltrating the pipe with those products and have witnessed it first hand with my cousins first install. His pipe started leaking the first year, he had water running into his basement through the wall and soaking wet insulation in the pipe. I have also seen the math that shows 1 deg. heat loss in your trench is roughly the equivalent to 1 extra cord of pine per year. The less wood I have to cut the better.