Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: Farmer85 on December 29, 2015, 06:01:57 PM
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I am considering making my own underground piping for my owb. Now I know this is a wore out subject and apologize in advance. Here is my story. I only wish I would of found this site before buying my 3 wrap underground piping 3 yrs ago that is now water logged. Nothing new here right? And first of all Don't tell me to buy logstor, I know I know. I was thinking about trying to recuperate some of my lost money in my 3 wrap junk and re use my pex. Now, I was thinking about re-digging my ditch and installing a drain tile at the bottom that would daylight out to drain away from everything. Its all down hill from owb to house so this should be easy. Backfilling up 6'' with clean rock. Now I thought of laying in 6'' sdr 35 from end to end. Capping both ends and pressure testing to be positive all joints hold up. I was going to block up pipe every so often to hold it up from the bottom of trench. I can buy closed cell foam to encapsulate entire pipe for about $300. I should have around $300 in pipe. I could wrap all with plastic but don't really see a need. As for the pex I can either leave the foil insulation on or buy foam insulation sticks before pulling in conduit. Once all is good foam up pipe ends to seal from heat loss inside area of pipe. I want to know what you all think about my idea and the closed cell foam? I am already out the money I wasted on 3 wrap, (my bad). I just cant afford the money on logstor or equivalent. My run is about 120' Another reason for my idea is I plan to add on to my house in the next 5-10 and not sure how I will go about using my lines. If I will have a new system I will either have to add bigger lines or add another loop. Currently I have 1'' pex running a total of around 350' round trip. I have a backhoe and drain tile. Can probably even get sdr 35 cheaper. Thinking total cost somewhere between $500-$600. I am questioning how the closed cell is holding up for people as ive read others doing it just not hearing how it has worked out. Thanks
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Foam kits; If you are going to use these take into consideration. These kits are low pressure. Temperatures will have ALOT of effect on yield. Wet or damp surface will also effect the yields.
Best bet is check with your local sprayfoam contractor, separate the lines with at least 1.5" foam board every 18" or so, enough so supply and return don touch and foam can get in between.
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I wasn't going to spray inside the pipe. I was thinking outside of it. And Ill be doing the work next summer when its high and dry. Ive been trying to contact local contractor to no avail. Thanks
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farmer, if the ditch is all down hill, how did your 3 wrap get waterlogged? Is the pex you are using 1 inch nominal or 1 1/4? Will the pipe size support your heat load after you go through the trouble of building it?
Finally think about your labor and not just material cost, time is money! Doing the job the right way the first time is always best but doing it 3 times is insanity!
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I Used sprayfoam when I first bought my boiler, that run was about 75 ft and can honestly tell you you won't be saving a ton of money by doing it, as Slim says if you are adding more heat load put the Logstor in the ground and be done.
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I read this forum a lot before I did my install 2 years ago. I did not want to pay the money for the logstor as well, but I believe it is a pay me now, or pay me later situation. I agree with Slim and Coolidge with all the labor involved in ripping up your yard again, put in Logstor. Every piping post on here seems to regret using "cheap" pipe options and I have not seen any negative Logstor posts.
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I did the homemade option as well, worked really well for a number of years, then I had one little spot that started to melt snow off, in a few years after that I had a nice green strip all winter from the boiler to the house.
I researched Logstor extensively for over a year before finally pulling the trigger on it, only failure I’ve found with it was right here on this forum from Slimjim, and you can’t blame the Logstor when a concrete guy drives a piece of rebar thru it.
Foam in trench is all the rage over at Hearth.com, given our always moist soils here on the heavy clay I’m not sure how long that would last no matter how well done.
I’ve used the kits, minimum of 80 degrees to get it to spray really nice and I can guarantee you’ll get to wear some of it before your done.
Due to ground conditions and finding a clay tile coming from the house we didn’t now was there, we dug up the corner to repair it then it started to rain and everything turned to slop on us, we left that corner open all winter to allow it to settle before repairing the tile, the Logstor was exposed to the air all winter, I seen snow and ice on it that never melted off till the air temps were high enough to melt all the snow in the hole.
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If anyone cares, the high price of Logstor is primarily due to two costly components that make up its construction: closed cell urethane foam and "EVOH" (ethylene vinyl alcohol, a copolymer).
Polyurethane foam insulation has historically cost more than other insulating materials but offers superior performance. Ethylene vinyl alcohol both tricky and expensive to manufacture. It is only manufactured by a handful of chemical processing facilities globally. Logstor uses EVOH as an oxygen barrier within its Pexa tubing and also as a membrane barrier between the Logstor polyethylene outer black casing and the polyurethane foam. It's purpose is to keep cyclopentane gas trapped within the foam for superior thermal insulation properties.
Chemistry lesson over. ;D
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We started out with 3/4" kited inside 3" sewer pipe that had foam insulation on every length,then ends glued together and foam sprayed into the joints.First winter I found I could dig down to the pipe at every joint in the middle of January.I would spray more foam in where the joints had separated,and whenever we would get a January thaw,water would leave the boiler at 180, and arrive at the house at 100, losing 80 degrees and freezing to death.The next summer I bit the bullet,it is not Logstor,but similar,it is 1" lines inside of several wraps of foam insulation like pool noodles inside of solid plastic field tile.Now water leaving the boiler at 180 arrives at 180. Long story short from experience,do the job right the first time ,saving money scrimping now will cost more in the long run.
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It was simply explained to me by a long time contributor to this industry : "Logstor will be the cheapest investment for your install".
Thought long and hard about that statement. I did end up purchasing 175' of $13 per foot pipe. I now see why. Leaves the boiler @ 180, gets to my house @ 178. Great product.
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I do not believe a guy can make a better pipe for the boiler that the logsor/therompex....if there was a way I WOULD HAVE DID IT ! If I was prez u COULD keep your doctor to ! ...I have spoken !!
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i did not want to spend 13.50 a foot for therm pex when i got my boiler,so i put my set up 14' away from my house, the building inspecter said it had to be 12'. and when its sowing and bad weather i walk out my slider door and load my boiler its rite there! works great for me! and kept the cost down!
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i did not want to spend 13.50 a foot for therm pex when i got my boiler,so i put my set up 14' away from my house, the building inspecter said it had to be 12'. and when its sowing and bad weather i walk out my slider door and load my boiler its rite there! works great for me! and kept the cost down!
Glad it works for you that way. At times when it’s well below zero I wouldn’t mind having ours a little closer to the house.
A lot of folks with multiple runs are gonna have to buy more than that eventually.
I have 118’ from the stove to the house and 122’ to the shop. Boiler is in such a spot that we can back a dump truck load of wood up to it and dump and never get off the drive. Our soils get extremely wet at times and you’re not gonna drive thru the yard to the boiler.
In the future if I can ever afford to build a new shop I’ll add a third run off the G400 and keep the old shop heated for oil changes and painting to keep the overspray off stuff in the new shop.
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My pipes now go into a crawl space at my house. I have cut the pipe and drained it. You can tell when we get a bunch of rain that my wood consumption goes up. After it dries up my heat loss is minimal. I have a gauge when it enters house and I don't lose but maybe a degree or two in 130' underground. SO since everyone is insisting logstor or thermopex, I cant find any locally. So can someone give me some prices shipped to a business in Sullivan Mo. Its like 120' so about 130' or so. I can change over the 20' in crawl space before it pops up to furnace. If the distance wasn't too far I would consider taking a road trip. Lets talk about my sizing. Currently I have 140' to furnace where it pops up into house. I have pex running through house another 25-30' to a dhw plate exchanger then it returns another 25-30' to the furnace heat exchanger, before finally making its way back down into crawl space and to the stove. So its roughly 340' ish through all 1'' line. There are 2 90* fittings at water heater. IF I add on to house I will have to have a separate heat exchanger that will be further yet, for a smaller furnace covering 900 sq ft more. can I do all of this with 1 loop? How big of pex? can I buy bigger pex now planning for future? What if I don't build will this big pipe hurt my efficiency? And finally a question I have been wanting to ask since I have described my system is pump size. I currently have a wilo star 32f I believe is the pump. I have noticed since I have a inline gauge where line enters house and after heat exchanger I lose around 25*+/- when furnace is running. Which makes me think my pump is undersized. Lots of questions
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It can be done in a single run but should be in a primary secondary loop, all heaters, boilers and domestic should be secondary loops off the primary loop, part of your issue could be that all your stuff is currently plumbed in series and restricting flow.
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slim jim, can you elaborate a bit. How do I obtain this? And what about size of the underground pipe?
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1 inch Logstor is just over 1 inch inside diameter, typical pex here in North America is nominally sized ( outside measurement), flow per gallon rates increase with pipe size as well as fitting sizes, close 90's reduce flow even more, plumbing in series as you appear to have yours is even worse as your plate exchanger then to the hot air exchanger will all have restriction and it all adds up, in a primary secondary loop, the main loop is wood boiler to inside and back to the wood boiler only, each heat loop is simply a set of tees placed closely together in the primary loop with it's own circ to pump from the primary out to the heat load and back to the primary loop, doing this ensures the best possible flow rate from the wood boiler to the home and back to the wood boiler
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thanks slim jim, My original question had to do with using 6'' sdr pipe. IF a person primed and glued 20' sticks and pressure tested this before backfilling why would you think this would fail? I am just curious. I considered doing closed cell foam around conduit also as a sealer and an insulator. Also no one has offered any prices for logstor or comparable to me. again I cannot find this locally. They all have the same as I used previously and that isn't happening again. I would just like a ballpark price to compare.Thanks guys
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The best prices I found were on ebay from freeheat4u
-1 1/4" $10.89 ft. $299.00 shipping
-1" $ 9.49ft. $349.00 shipping
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Also no one has offered any prices for logstor or comparable to me. again I cannot find this locally. They all have the same as I used previously and that isn't happening again. I would just like a ballpark price to compare.Thanks guys
GOOGLE is an amazing tool. I searched "Logstor dual pex flex for sale" and came up with several sellers. I randomly picked a pricing link for J&S Pipe in Michigan and their pricing was $11.50 per foot length plus shipping charges.
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Anderson's is cheaper directly from their website rather than from eBay. www.freeheat4u.com
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From there website
1 1/4" $10.99 ft
1" $8.99 ft
32mm $9.99. Ft
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I can't find Logstor on that site.
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Logstor 's the only way to go one continues run of pipe with no joints
Why waste time money and labor save it some place else
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http://freeheat4u.com/REHAU-Spray-Foam-Insulated-Pex_c_23.html
Rehau is the parent company that makes Logstor
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I don't understand what the 32mm size is. Here are the I.D. measurement is off urecons website. Anderson's has 3 different sizes listed 32mm,1",and,1 1/4"
1 1/4" = 32.6mm
1". =26.2mm
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I could not remember where I bought mine, but searched on Google and it came up along with several others. Classic comfort in Ohio. Call and they will give you a price as well as a shipping quote. Great people to deal with!
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I didn't realize Rehau and Logstor are the same. Thanks
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THEY ARE NOT the same!
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ok. so one company makes both products, or i'm just too thick to understand? THANKS
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Logstor: https://www.logstor.com/about-us/profile
Rehau: http://www.rehau.com/us-en/company/about-us/company-history
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I thought they were the same. What's the difference or how can you tell between the two.