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Closed cell foam is it an oxygen barrier

GarfieldGarfield Posts: 38Member
I am installing a wood hot water system. I have read about a method of insulating the underground lines where you dig a ditch and run your lines then hire a spray foam contractor to spray closed cell foam in the ditch instead of buying an insulated lineset. My question is will the closed cell foam function as an oxygen barrier. (buying non oxygen barrier pex is cheaper)

Comments

  • kcoppkcopp Posts: 3,368Member
    Is the outdoor boiler a pressurized boiler or is it a open hot water "furnace" ? Many are not pressurized vessels and are open to the atmosphere...
  • psb75psb75 Posts: 136Member
    Its never a good idea to 'cheap out' on the underground portion of a substantial heating installation. Things like undersized pipe, or improperly insulated pipe, or piping unprotected from groundwater.
  • KC_JonesKC_Jones Posts: 4,280Member
    Make sure you size the lines properly too. Undersized lines seems to be a recurring theme around here.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    https://www.facebook.com/media/set/?set=a.10202744301871904.1073741828.1330391881&type=1&l=c34ad6ee78
  • GarfieldGarfield Posts: 38Member
    It is pressurized. I have read enough here to understand that the oxygen in the water gets depleted by eating a small amount of iron from the system. I would like to understand more about how much oxygen gets through nonoxygen barrier Pex? If you have a leak and add 10 gallons of water versus having 10 feet of non oxygen barrier pex. What is the unit of measurement to say how much oxygen is leaking in?
  • ZmanZman Posts: 5,334Member
    Non O2 barrier tubing will eventually allow enough O2 to enter to destroy any ferrous metals in the system. It happens, just believe.
    Buy the O2 barrier tubing and sleep at night.
    How are you sizing the tubing? As noted above, these are often undersized.
    If you decide to insulate in place, be careful of the installation. You need to wrap the tubing to protect it chemically and be careful of the lifts when insulating. The insulation can melt the tubing if installed to quickly.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • GarfieldGarfield Posts: 38Member
    I have a 3800 gallon tank off of a propane delivery truck that I was going to use for thermal storage. My other concern is with this much water do I need to put some kind of sacrificial iron in the tank or something to get the oxygen out?
  • mikeg2015mikeg2015 Posts: 1,043Member
    Garfield said:

    I have a 3800 gallon tank off of a propane delivery truck that I was going to use for thermal storage. My other concern is with this much water do I need to put some kind of sacrificial iron in the tank or something to get the oxygen out?

    You should just use a good water treatment ot make sure the PH is high enough to reduce corrosion. Most glycol already has some additives I think but not bad to add more to protect the boiler. You are using freeze protection correct? Normally 25-30% depending on your climate. Any time I’ve seen freeze protection skipped the boiler eventually freezes and is destroyed.

  • GarfieldGarfield Posts: 38Member
    I am intending to put this in an insulated carport with a baseboard heater set to 45° and a propane vent free heater In case of power loss. There is the cost of the glycol in addition to the reduced heat transfer.
  • Solid_Fuel_ManSolid_Fuel_Man Posts: 1,760Member
    Do not buy non-oxygen pex, to unders understand how oxygen gets through the tube you just have to think of it like a screen door on a dusty road. The water is like the bugs, they are too big to get through the screen and therefore are all kept outside. The dust, however, is the oxygen, it passes through with little problem.

    Oxygen barrier is like a much finer screen, almost no dust (oxygen) can get through and all is well. You will have a closed loop system, the oxygen barrier keeps it closed.

    Non oxygen barrier is open loop in the sense of oxygen ingres.
    Serving Northern Maine HVAC, and Controls
  • GarfieldGarfield Posts: 38Member
    OK I have come across this two and three eights inch OD 2 inch ID used petroleum pipe. I assume it is just mild steel pipe.
    It looks like the blue 4 x 8 sheets of foam insulation that people put against foundations is almost waterproof and retains its R-value pretty well even when submerged. I’m thinking of cutting this in 1 foot strips and slitting it so that it would basically be a top and a bottom piece and then sandwich it with threaded rod. Seems to me that it would not hurt if it got wet as long as the insulation retained R-value.
  • GroundUpGroundUp Posts: 672Member
    The problem is that these lines are usually buried in dirt that is otherwise saturated with water, so there will be heat transfer to that water no matter what, if the foam is wet. Spend the money and do it once the right way. CB Thermopex, Rehau Insulpex, Rovanco Rhinoflex, or Logstor PexFlex are the only 4 choices for these applications.
  • DZoroDZoro Posts: 936Member
    I have built those foam boxes in the 80's when we didn't have insulated pipe systems. Tore all of those systems out a few years later, all saturated and waterlogged, junk.
    @GroundUp is right buy a good insulated pipe with O2 barrier tubing inside. Digging up a yard isn't fun, do it right the first time.
    D
  • GarfieldGarfield Posts: 38Member
    Dzoro did you build it out of the Styrofoam type of insulation or the dense blue or pink stuff?
  • Solid_Fuel_ManSolid_Fuel_Man Posts: 1,760Member
    My solution has always been to use as little underground as possible. Indoor boilers, or indoor boilers in an attached building with no indoor access if that floats your boat.

    Also sent the water through the underground at as low a temperature as can be used (mix at the boiler).

    Personally I'd sleeve whatever pipe you use in a 4-6" PVC or some type of culvert as to avoid any ground contact.

    I've seen paths of melted snow between boilers and buildings with some of the premade pex systems.
    Serving Northern Maine HVAC, and Controls
  • DZoroDZoro Posts: 936Member
    We built them out of the blue and pink. Then wrapped the box in plastic. Water still penetrated and soaked the Styrofoam. You may get a year of no saturation of the Styrofoam but eventually it breaks down. When it does you might as well just lay the pipes in the trench, because all insulation value is gone. It's amazing how that Styrofoam acts like a sponge and actually will not let the water go.
    D
  • psb75psb75 Posts: 136Member
    Listen to GroundUp.
  • TAGTAG Posts: 182Member
    You should use good pipe -- the proper pipe for heating has the barrier.

    My 1920 house in Chestnut Hill has underground pipes to the garage insulated with closed cell foam. Closed foam is waterproof ...

    They need to build up the layers in the trench -- put the pipe in place and layer again.

    In my case we uncovered the old steel pipes and sprayed them -- my foam guy said it's common. He is the one who told me about it. Only cost effective if very long or part of a bigger job.

  • GarfieldGarfield Posts: 38Member
    350 feet is my length.
  • TAGTAG Posts: 182Member
    350 -- that's a lot ... have you called around and asked ?

    My guess is the insulted pipe will be less money -- I had at least 5 inches of foam around my pipes.
  • ChrisJChrisJ Posts: 10,243Member
    Can I ask what exactly is the point in an outdoor boiler?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • TAGTAG Posts: 182Member
    Chrisj -- they burn wood .... or in some cases (coal). Normally placed out of the way -- for both smoke/soot and to hide .. they tend to be large as you are heating a whole house ... plus all the fuel.
  • ChrisJChrisJ Posts: 10,243Member
    > @TAG said:
    > Chrisj -- they burn wood .... or in some cases (coal). Normally placed out of the way -- for both smoke/soot and to hide .. they tend to be large as you are heating a whole house ... plus all the fuel.

    Coal boilers used to be installed in basements where they could easily be fed. The chimneys terminated above the roof and most heat lost was lost into the structure.

    From what I've seen outdoor wood burners often dump smoke right into the house / your face as You're working outside because the stack is only a few feet up. You also have to get dressed to go out and feed it and all of the loss is outside.

    I completely do not understand. It seems like taking the old concept and taking 10 steps back.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • GroundUpGroundUp Posts: 672Member
    edited December 2
    How is it difficult to grasp the idea of keeping the mess and fire hazard out of your house? The smoke is a non-issue, stack can easily be added if necessary but gasification wood burners don't smoke anyway. Most people leave their house every day anyway, it's not much trouble to walk past the stove and toss some fuel in on the way to the car. It has its caveats too of course, as does any system, but saves a lot of people a lot of money albeit a lot of work. The more square footage and more buildings, the higher the savings.

    For Garfield, what exactly will you be heating with this unit and what model is it? 350ft one way is quite a distance and will require a larger diameter piping than you're probably anticipating. Also 3800 gallons of storage is quite ridiculous, shut away in a carport with tons of exposure for heat loss. Underground lines aside, we have to talk a little about the rest of the system too
  • GarfieldGarfield Posts: 38Member
    edited December 2
    First of all thank you all for your help . 900 sf house and 2800 sf house and an In ground pool. The pool is 50 feet from the carport, 900 sf house is 100 feet and 2800 sf house is 350 feet. I had done some reading on here and it seems like the common mistakes were not enough storage and line sets that were too small. Pool pump and filter will also be in the same carport so I can heat that with an exchanger and no underground lines. The 900 sf house I was planning to buy the 1 inch line set everyone is recommending. The 2800 sf house I am trying to figure out something else. Currently I’m considering an 8 inch pvc pipe with 2-2 inch steel lines with insulation on the top half of the 8 inch pvc and the bottom open so it can drain into the basement if it collects moisture. I have a 3800 gallon propane tank off of a delivery truck and an Orlan eko 80 boiler.
  • DZoroDZoro Posts: 936Member
    What is your reasoning on a 3800 gallon storage tank? What are you trying to accomplish? That is a extreme amount of water to maintain heat.
    D
  • GarfieldGarfield Posts: 38Member
    Well I have a pretty good size boiler and I see people on here say two 1000 gallon tanks is ideal and when I saw this for $1300 that’s less than I would’ve had in two 1000 gallon tanks so I bought it. I have done some reading it seems like I need aN automated way to put the tank on its own zone or it’s gonna take me three days to get heat built up.
  • psb75psb75 Posts: 136Member
    You better believe that 3.8K gal. tank will be "on its own zone." The boiler's ONLY "job" will be to heat that tank. The tank's "job" will be to heat the buildings and provide DHW. Oh, by the way YOUR "new job" will be providing fuel for the hungry boiler. That is a BIG tank. You should design well and carefully.
  • GarfieldGarfield Posts: 38Member
    I was going to have closed cell foam sprayed on the outside of that tank and the inside of the carport.
  • TAGTAG Posts: 182Member
    Maybe things have changed .. but, when I looked into them years ago the goal was matching the heat load w/ long burn? Load it and forget ..... This was for property in PA where both coal and hardwood is available. Don't remember any system with a storage tank for BTU's ..... the fire was controlled.

    The systems are under pressure from those wanting to limit the emissions - some areas have banned them. I wonder if the tank is a way to avoid partial firing -- that's when you get the most smoke.
  • psb75psb75 Posts: 136Member
    Insulating the tank and building is a good idea. "Batch" burning is definitely the way to go--load it and then "burn it up." In winter--one fire a day. Certainly match the amount of fuel per "batch" (# of BTUs) to the "space" in the tank for "use-able" BTUs. Spring-fall season could be one fire every two or three days.
  • GroundUpGroundUp Posts: 672Member
    The Eko80 has a 16.4 cubic foot firebox. With good, dry, hardwood at 75% efficiency (yes they claim 90+ but it's probably closer to 65-70 with all things considered so let's call it 75 for benefit of the doubt), you can expect 18 million BTU per cord (128 cubic feet) of wood. So divided up, the maximum you can possibly achieve with a single loading is about 2.25 million BTU. That's with every single square inch of the firebox full of wood, which will never happen, so again we derate by 20% for air space which brings you down to 1.8M. That is the best possible realistic scenario, with everything perfect, which again is not likely in most cases but we'll roll with it. So 3800 gallons of water weighs 31,654 LBS, and we know a BTU is the the amount of heat it takes to raise 1 LB of water 1 degree. An entire load of wood under perfect conditions would raise your 3800 gallons of water only 57 degrees and I can't even fathom the standby loss of a tank of that size with a 100+ degree differential to the outdoors even with several inches of foam encapsulating it. What kind of heat emitters are in each house and what are the required water temps? If something high temp, like baseboard or CI rads that were designed for 180 degree water, your stored heat has very limited potential.

    Even the good, foamed underground lines will dump 5-10,000 BTU per hour in the dirt per 100ft length depending on the terrain and flow rates so if we add that all together with your proposed system, we're down to maybe 1M usable BTU out of a single loading, not including standby loss. What's the heat load in these two houses? How big is the pool? Moral of the story here is that you're going to be loading this stove, packed to the brim, 2-3 times a day when it's cold out. That's a full 4x4x8 cord of wood every 3-4 days, all winter long. Are you sure you want to make this investment? It may be more realistic to do away with the whole kaboodle and spend the money on a nice EPA approved outdoor boiler, say from Heatmaster or Crown Royal perhaps, that are meant to idle between cycles and provide all necessary BTU on demand when necessary. This avoids the whole storage issue completely. If you could sell the Eko and tank, and avoid the cost of the carport and all the spray foam, not to mention several hundred hours of labor, you'd probably be in a similar price range just buying the proper OWB and lines and do the install in a day. I'm not trying to change your mind necessarily, but as someone who does this solid fuel stuff daily I've created some ups and downs based on experience and if the goal is cost efficiency and simplicity, I urge you to consider another route and weigh the options before you dive into either one
  • GarfieldGarfield Posts: 38Member
    GroundUp thank you for taking time to educate. The truth is I just want to do this I think it’ll be fun. I’ve already paid for the tank and the boiler. I don’t have a heat load calculation on either of those houses but they’re both built in the 1990s with average everything as far as insulation etc. they both have typical heat pump with back up electric heat strips. So I would need to add a proper water to air exchanger to the big house on the little house I’ll probably just come up with a heat exchanger that has a fan and set it in the floor because it’s a pretty small house that’s unoccupied most of the time. In the big house we currently have two electric 50 gallon water heater’s and occasionally run out of hot water. Was thinking about piping A hot water exchanger ahead of the water to air exchanger to feed a preheat tank and keep the electric water heaters because sometimes this boiler won’t be on. The swimming pool doesn’t exist yet but I think it will be done in the summer.
  • GroundUpGroundUp Posts: 672Member
    Fair enough. The only thing I really have to stress is the underground lines. The run to the bigger house is going to need to be a minimum of 1-1/4" ID for both heating and DHW, and yes it will be expensive, but worth every penny for the premade foamed stuff. If you have a Central Boiler dealer anywhere nearby, their 1-1/4" Thermopex is typically the best bang for the buck and is O2 barrier. As for the DHW, it's as simple as putting a 30-40 plate exchanger in the cold domestic line before it enters the electric tank so it preheats the water before it enters the tank. You can leave the elements energized at all times for backup, but as long as you use some hot water every day they will never power up as the tank will already be hot from the wood boiler. No need for any sort of preheat tank. In summer the electric will just resume as normal- no need for bypass or anything
  • GarfieldGarfield Posts: 38Member
    How do I send a private message to someone on this forum?
  • Erin Holohan HaskellErin Holohan Haskell Posts: 1,172Member, Moderator, Administrator
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