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Thread: baseboard heat

  1. #1

    Default baseboard heat

    i want to run anti freeze in my heating system.i have a wood stove for the main heat now. how many gallons does the system hold....it is a two story home and about 2400 sq.ft.with no hot water tank. how well does the antifreeze mix heat? i am going to do this myself....what do i need to know..

  2. #2
    Join Date
    Feb 2008
    Posts
    556

    Default Re: baseboard heat

    phil,

    Heating techs recommend non-toxic antifreeze (propylene glycol) be used only after all other alternatives have been exhausted.

    The reasons for this are:

    1) it costs $6-$10/gallon.
    2) under certain conditions it can get into your drinking supply water.
    3) an additional fixture has to be added to your heating system (backflow preventer).
    4) there is a 3-5% loss in heating efficiency over straight water.
    5) it can combine with calcium in hard water to produce some sludge.
    6) it tends to find pinhole leaks in the piping & produce minor leaks.
    7) it has to be replaced if subsequent work is done on the heating system.

    Could you provide more info as to the low temps you are experiencing in your area, & have you had problems in past winters with frozen/burst pipes.

    Other methods to consider could be to keep the circulator going during hard weather---moving water will not freeze.

    If just SOME pipes are vunerable to freezing, they can often be re-installed to another part of the house, or more insulation, or an electric heat cable can be used to prevent freezing.

    If you still feel the need for antifreeze, make sure you buy the non-toxic kind at HD/Lowe's, or a plumbing supply house---you'll probably get a better price at a plumbing supply house.

    DO NOT USE ethylene glycol or automotive antifreeze--it is toxic and is not used in heating systems.

    You would have to calculate the total length of all heat pipes, plus the contents of the boiler to obtain THE TOTAL GALLONS OF WATER in the system.

    At the raypak site below you can then calculate how many gallons of antifreeze to use to get protection at the lowest temps you are experiencing in your area.

    The raypak site has how much water each foot of copper tubing holds, according to its diameter.

    Check your boiler installation manual (Google your boiler model # to find it on-line if you don't have one) to determine how many gallons of water your boiler holds.

    Baseboard is almost always 3/4" copper tubing.

    Thus a boiler may hold 15 gal + 230' of 3/4" copper pipe = 230 X .025 = 5.25 gal + 110' of 1 1/4" pipe X .068 = 7.48 gal + 200' of 1/2" piping X .015 = 3.0 gal. = 30.73 gal for water in heating system X 30% (.30) = 9.3 gallons of antifreeze to be added to get 4 degree protection, or 31 gal X 40% (.40) = 12.4 gal of antifreeze for -13 degree protection.
    http://advice.thisoldhouse.com/showthread.php?t=9044
    http://www.raypak.com/afreeze.htm
    http://www.heatinghelp.com/pdfs/235.pdf
    Last edited by NashuaTech; 11-09-2008 at 01:57 PM.

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