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Question on Insulating Pipes

Post in 'The Boiler Room - Wood Boilers and Furnaces' started by hiker88, Jun 6, 2013.

  1. hiker88

    hiker88 Burning Hunk

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    I brought my system online last October and didn't do anything as far as insulating the pipes. I thought I would keep an eye on things to make sure I didn't have any leaks.

    I figured that when summer came, I would probably want to insulate the pipes because I am using the boiler for dhw and I figured my downstairs family room might get hot when I ran the boiler.

    So far, that hasn't been the case. The basement has stayed very comfortable, but I'm wondering if I should still insulate the pipes from an efficiency perspective?

    I am using weighted burns and with no heat load, I can raise the tank top temperature to my goal temp with a multiplier of 2. I.e., if the tank top is at 45c, and I want to raise it to 85c, I can raise it 40c by burning 80 lbs of wood (85c-45c)*2. It takes about 3-4 hours for the burn, with stack temps approximately 200c and wood mc is about 15-20%. There is usually a 5-8c temp difference between storage top and bottom (bottom being lower). My storage is unpressurized.

    So, what are the thoughts on insulating the pipes? I also thought I might just insulate from boiler supply to storage and then back to the boiler return. I'm thinking that when I am using the boiler for heat, the heat off the pipes just warms the rest of the house anyway.

    If you respond that I should insulate the pipes, I would appreciate any thoughts on how to go about it. I was wondering if the bag of foam pieces you can get at Lowes or Home Depot do anything.

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  2. maple1

    maple1 Minister of Fire

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    How long are you able to go between burns?

    I'm sort of in the same boat, but have been picking away at insulating. Insulating pipe is a big PITA when the piping is mostly fittings and things are in a tight space. Mine is a sort of hodge podge. What I can get the easy-to-install foam slitted stuff to fit on I do that (I can get stuff here up to 1-1/4" BI). That leaves out a lot of fittings - so I'm using some regular fiberglass pipe wrap stuff for that, getting it wrapped around & taped over with house wrap tape to make it stay put & overlaping the foam. Then I'm putting a layer of the foil bubble wrap type stuff over everything, taping joints & laps with foil tape. I end up with pretty bulky looking pipe sections, and it doesn't look too bad overall - but is a very tedious process.

    I'd just say to go by feel - if it gets to feeling warmer than it should or you'd like around your piping & tanks, then try to insulate. We've only had a couple of hot days here so far - I started a burn early on one of those days. By the time the burn ended it was way too warm for me in the house - seemed the amount of heat coming off the smoke pipe amplified itself in the heat & humidity. From that I think I am not going to burn steady all summer - just too much added heat to the house on hot days even if I get it down to not very much.

    My bigger issues in burning for DHW in summer have been extending my time between burns. I am still sorting out my DHW-related pumping things. When I first started I was barely able to get to day two before I'd have to burn again. Now I'm at three days with more sorting & changes to come.

    (That kind of rambled...)
  3. hiker88

    hiker88 Burning Hunk

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    I go about 4-5 days in between burns right now.
  4. Bob Rohr

    Bob Rohr Minister of Fire

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    If you are running AC in your home, upstairs maybe? Good chance some of the heat from the boiler is, or will be added to the cooling load. Or at least adding some heat to the space that you don't need or want, even without ac running.

    The near boiler piping should be fiberglass or any product able to withstand 210F plus temperatures. Even the HVAC EPDM stuff gets crunchy after experiencing high temperature operation for extended periods. Fiberglass can take the heat and last a long time.

    Look for an industrial insulation supplier they have the insulation and fitting boots to make a nice looking job of it. Insulating piping is a PITA when you have a lot of fittings.
    BoilerMan likes this.
  5. jebatty

    jebatty Minister of Fire

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    I tend to think the better question is "are you getting the heat you need, especially not too much?" If the current setup provides the heat you need, and not too much, why insulate? Heat will come from the plumbing or from the tank, and if the heat you need is coming from the plumbing, then it doesn't have to come from the tank.

    In my system, boiler, tank and plumbing all are in the heated space. My pipes are insulated but I did not install check valves and there is plenty of thermo-siphoning going on from the tank after a burn. One part of me says to put in check valves, but the part that made the decision says no. Why not? Because I need that heat anyway and that heat is supplied without any pumps running, no electricity being used.

    So, if your space is warmer than you want, then insulate. Else, leave it alone, unless there is some other purpose you want the insulation to meet.
    BoilerMan likes this.
  6. hiker88

    hiker88 Burning Hunk

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    Initially, I was mostly concerned about the living spaces getting too hot during the summer since I am using the system for DHW. So far, it hasn't been an issue. Then I started wondering if I could go longer in between burns, but I'm already going 4-5 days. So, maybe it is more trouble than it is worth.
  7. maple1

    maple1 Minister of Fire

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    I'm kind of curious on how long between firings everyone is going in heating their DHW from storage in the summer. I'm barely making it to day 3 thus far, but still making changes/improvements. From the bits I have read it sounds like I might not get a whole lot more time anyway with just 660 gallons of storage - would like to make it 5 days though.
  8. Coal Reaper

    Coal Reaper Minister of Fire

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    i am getting five days, barely. and i still need to do some more insulating of lines and fittings in the barn. tanks get down to 130* top and 100* bottom before i recharge. takes 2.5 loads of wood to get back to 200 top and 180 bottom. we used to have a brief period of cold water while the oil boiler was coming up to temp to charge the DHW. not any more. ==c i think i am on par to get 3 months of DHW out of a cord of wood. idk if that is good or not?
  9. maple1

    maple1 Minister of Fire

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    What do you have for a HX? With my sidearm, my storage is pretty well done after it drops below 140 or so on top. Maybe 135. I put the new Alpha in last week, and have an Ecocirc that I ordered waiting for me to pick up at the supplier, to put in on the DHW side. I'll see how that goes before deciding on adding a flat plate or not. Part of my problem is my sidearm isn't flowing the best by convection - that didn't matter in heating season when the supply water was always hotter. Even with that though I'm not expecting to get much of an improvement in approach - but I should be able to heat my DHW tank up quicker to limit pumping times.

    Still have some insulating to finish up too - when I get round to it...
  10. skfire

    skfire Feeling the Heat

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  11. Coal Reaper

    Coal Reaper Minister of Fire

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    indirect. and actually my dial thermometer is about 18" below the top of my tank so i figure i have a little more heat above where it is reading. have not had a miss in hot water supply so far running that thermometer down to 130*. i will have the x-300 hooked up soon and will have a thermocouple on the pipe coming out of the storage tank. my DHW tank should be set somewhere around 130* but i have not actually double checked this. i am running set-point mode on a taco bumble bee at 140*. this seems to be working very well as i have not caught it running for any extraordinary amount of time. it cranks 16.5gpm at 42 watts to clear the lines and then backs off eventually to 6gpm at 9 or 11 watts to maintain that 140* going back to storage.
    BoilerMan likes this.
  12. hiker88

    hiker88 Burning Hunk

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