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Installing FHW pipe to heat basement - On to the next question.

Post in 'DIY and General non-hearth advice' started by daveswoodhauler, Dec 13, 2011.

  1. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Ok, so I have the rigid installation and framing completed in the basement for a finished living room.
    Getting ready to start running the copper pipe to connect to our oil boiler (forced hot water) and I am confused on the correct piping to get. (My heating guy is going to install the zone valves and hookup to the boiler, but I am going to run all the lines to save some money..he is going to est the pressure prior to hooking up)
    I measured the current pipe for the 1st and 2nd floor zone, and it looks like it is 7/8 diameter, which would be called 3/4", correct?
    Also, I see some 3/4" labeled type L and Type M, and it looks like the type M has a higher PSI rating?
    Just not sure what to purchase...not sure if I can tell if I currently have L or M? Any hints/tricks?

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  2. gpcollen1

    gpcollen1 Minister of Fire

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    I would either ask the guy who is doing the boiler work or the guys at the plumbing supply. At the supply house, I usually let them know that a plumber or electrician is doing the work b/c sometimes they are not helpful to homeowner/DIYers - even if I am doing the work.

    This is what the interwebs told me:

    Type K

    This type comes in sizes from 3/8" to 12". It can be used in underground installations and for almost all general heating and plumbing purposes. Type K has approximately the same wall thickness as usable thicknesses of iron pipe after it has been threaded. It finds employment in all sorts of buildings, from the largest to the smallest, but particularly in areas where the water is highly corrosive. Its bursting pressure is high: 3/4" Type K copper tubing has a bursting pressure of more than 5,000 lbs. per sq. inch.

    Type L

    Coming in the same sizes as K, Type L copper tubing is used chiefly for medium-pressure interior plumbing, and for steam and hot-water heating systems. It should not be used outdoors in underground connections. The wall thickness of Type L is about half way between the wall thicknesses of Types K and M. In 3/4" size, its bursting pressure is about 4,000 pounds per square inch.

    Type M

    Available in sizes from 2 1/2" to 12", Type M is used where water conditions are normal for low-pressure plumbing. It is also used in low-pressure steam and hot-water heating systems. Its bursting pressure is 3,000 pounds per square inch in the 3/4" size.

    As a general rule, use Type K whenever possible, Type L only when necessary, and Type M rarely. Type M might be used, for example, in a place where piping will not be subjected to considerable pressure and a lighter tubing is necessary.
  3. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Thanks CT. The application will be all indoors (no runs outside/underground) Basically, a small loop in the basement to heat appx 450/sq/ft.
    I'll check with my furnace guy to see what he recommends.
  4. Dune

    Dune Minister of Fire

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    M is used for heat in Mass, and cannot be used for potable water. M is lighter than L, therefore cheaper. For potable water L is used.
  5. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Thanks Dune. Type M helps the pocket as well.
  6. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Ok, got more questions, so figured I woudl fire away.

    2.) Due to this being a basement install, I will be running the piping through the stud walls, and then out the wall for the registers. From what I have read, I should be using a 1 1/2 hole in the stud along with a gasket? (Basically, I am thinking that the piping will run inside the wall until where the register will be, then pop back in the wall, and then exit again for the next register?) The heating guy indicated that I should just run the entire run on the outside of the wall, but I am not sure if I want to have the entire perimeter surrounds by baseboard.

    3.) Is there a certain distance that the piping should both exit from the wall, and also a distance that the piping should be above the finished floor?

    For some specifics, we live in Central Massachusetts with a poured foundation. 75% of the foundation is below grade, with appx 2 feet or so above ground. The space will be appx 450 sq feet, and I've used rigid 1" (R5) insulation, then 2 X 4 studs, then will have R 13 in between the studs.
    My heating professional is going to be doing the pressure test and final hookups to the boiler, but is allowing me to run the piping so I can save some money.
  7. Dune

    Dune Minister of Fire

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    Have your Pro do a heat loss calculation of the area to determine how many feet of baseboard heat you need. He probably meant that you should run the loop around the whole basement, not the baseboard heat. Sounds like he plans to use mono-flo tees and a continuous loop. If so, he will just cut them in after. When you go to the plumbing supply, for the pipe, get the hangers too.
    You will likely use "micky mouse" hangers. They will fit in a much smaller hole than 1.5". I usally use 1.25 or 1.375" self feed bits for 3/4" pipe (tube). If you have a powerful enough drill motor that is. You must mark your holes acurately for the pipe to line up.

    As to the stubbing out height, you will need to know what baseboard you are using, but as I said, sounds like he just wants you to run a loop, not stub out. You clearly need to clarify this with your contractor.

    Oop,s rereading your post, I think you mean you are doing the piping as well as the heat. If that is the case, you must get the baseboard heat as well. Mount the back part of the heat sheild to the wall. A couple screws into a stud every few feet. Be sure to mount it at least inch off the floor if you plan to install carpet.
    Baseboard heat pipe is even thinner than M tube, advance the cutter into it slowly if you must cut it. Before soldering baseboard heat pipe, wipe the area well with a clean rag, as it comes oiled. Then sand and flux as usual. Once you mount the heat, you will see where to stub out your pipes.
  8. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Thanks Dune. Looks like I've got some discussion to have with my heating tech.
    On the heat loss calculator, I came up with 5905 watts and 20154 BTUHS, but those figures are a little greek to me..used a disign temp of 70 degrees.
    I forgot on my earlier post regarding the insulation, that I have R19 in between the ceiling joists (between basement ceiling and first floor) and I'll be using a typical drop ceiling. When I was looking at electric heat, I was coming up with only perhaps 16-20 feet of electric baseboard, so wondering if that would be about right for the hot water registers as well.
    Again, thanks for the help...I've got some learning/reading to do.
    Benn monitoring my temps in the basement furthest away from the boiler, and temps so far this december are ranging from 56-62 degrees. (Usually 58-59 on those days where we have the insert running and the boiler is not running)
  9. mepellet

    mepellet Minister of Fire

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    Have you considered using PEX tubing instead of the copper? PEX is cheaper, easier to install, and won't burst if the water freezes. I personally would run the piping on the room side of the drywall (not in the wall as you are thinking). The piping will give off some heat. Why heat the wall cavity? It will also be much easier to fix any problems down the road.

    To figure out how many feet of hw baseboard you need then it is as simple as looking at the hw baseboard specs.

    Are you planning on taking out the insulation in the ceiling?

    Is the basement slab insulated?
  10. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Well, I don't know anything about the PEX tubing, so I wasn't even sure if I could use that approach if what I currently have is copper...could use some more info on this if ya don't mind.
    I was going to leave the insulation in the ceiling between the basement and 1st floor, and as far as I know the slab is not insulated in the basement. If I measure the wall temps, its about 6-7 degrees warmer than the uninsulated foundation walls, and floor temps are running appx 58 degrees.
  11. Deuce95ci

    Deuce95ci New Member

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    Have seen pex used a few times but I will never use it personally on any customers houses. I use 3/4" type K and L where needed. I set systems to run at 15-18 Lbs.
  12. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Ok, so I am looking into this PEX possibility for running the heating in my basement, but had a question.
    Wouldn't the hot water baseboards and piping remain much warmer with the copper piping? (i.e. I would think that the copper pipes would retain the heat much more than pex?)
    Right now my walls and ceiling are wide open, so installing the copper really wouldn't be too difficult as everything is wide open. (I can understand the installation ease of the pex if you are working in touch spaces with multiple inaccessible corners)
  13. MasterMech

    MasterMech Guest

    Copper is one of the best heat conductors therefor it absorbs and disperses heat much more rapidly than Pex. You should have the least thermal loss with Pex.
  14. daveswoodhauler

    daveswoodhauler Minister of Fire

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    Ok, on to another question

    Any pros'cons of having the pex run from the boiler to the baseboard, and then just using copper for the basboard piping, and then pex back to the return on the boiler? Or just run Pex for the whole job?

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