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Thread: baseboard heat

  1. #1
    Join Date
    Mar 2008
    Location
    North West of Philadelphia
    Posts
    7

    Default baseboard heat

    My sons bedroom has always been cooler then the other bedrooms. We've done the obvious, replaced the windows (very old and leaking air), added/corrected insulation (some missing, incorrectly installed, etc.), added insulation in the attic overhead. All with SOME effect but still not great. I suggested that maybe there was a bypass valve somewhere, though I've never seen anything like it in the house. When we removed the baseboard covers to look we discovered another "economy" job of the builder. He must have run out of the "finned" pipe so finished the job with plain 3/4" copper pipe.

    Is there any way to retro fit fins, or something that will do the same job, onto the 3/4" copper pipe? I would rather not have to cut out, about 20', of plain pipe and solder in the new.

    Thanks,

    RSCH

  2. #2
    Join Date
    Aug 2007
    Posts
    443

    Default Re: baseboard heat

    I congratulate you on the work & expense you've done so far to improve the heat retention of your son's room--your efforts are by no means wasted & will pay dividends.

    Try a few things for me, and then post back with further info.

    1) Count the number of feet of baseboard that actually have fins and multiply by 500.

    2) Then get the sq. footage of the room by multiplying the length by the width.

    Most rooms have a heat loss factor of between 40 and 60 btu/hr per sq.ft., depending on the ceiling height, amount of insulation in the walls, # of windows, etc.---advise if the ceilings are over 8'.

    This means that ~40 btu/hr per sq.ft. are oozing thru the walls to the outside of the house, & it takes 40 btu/hr of heat per square foot of floor space to re-heat the room.

    3) Turn up the heat & leave the baseboard covers off & place your hand around the bare pipe---if it's real hot, you won't be able to hold it for more than a second or two ("real hot" would equate to ~ 180 degrees water temperature); go to the boiler & make a note of the boiler water temp from the temp gauge.

    Baseboard should be installed according to its output (about 500 btu/hr per foot, depending on water temp of ~170 degrees), AND the square footage of the room (heat loss calculation of how many btu's/hour are bleeding out the walls).

    Thus if your son's bedroom is 15 X 10 & we use a heat loss factor of 40, the heat loss and baseboard lengths should read: 15 X 10 = 150 sq.ft. X 40 (amount of btu heat required per sq.ft.) = 6000 (room heat loss in btu/hr) divided by 500 (amt of baseboard btu heat output per ft) = 12 feet of baseboard should be in the room.

    You should do the free heat loss calculations below to get a more precise number for the heat loss calculation for the room.

    If the copper pipe connected to the baseboard doesn't feel very hot & you can leave your hand on it for over 5 seconds, the hot water in the system going to this particular baseboard is not hot enough to deliver the needed heat.

    This could be for several reasons--but can usually be remedied.

    Please advise if you find this to be so.

    It's common for installers to install partial copper pipe, instead of finned baseboard if their heat loss calculation indicates that they will overheat the room if they install baseboard the full length of the room; this is especially true if you have a hW piping system that is SERIES LOOP, where all of the house's baseboard are installed directly in series, so that the individual baseboards can't be shut off or throttled down separately if it gets too hot in the room.

    Extending the baseboard covers to the end of the room is mostly for aesthetic purposes, but DOES allow for additional finned sections to be easily installed to raise the amount of heat in a room.

    There is no practical way fins can be "glued" on to the bare copper pipe---there's no need to--an additional 8' or longer section of baseboard can be easily installed if the water temp at the boiler can't be brought up a little higher (it usually can).

    Your son's bedroom may be at "the end of the line" as far as the baseboard in the rest of the house is concerned---this would mean the hot water has cooled by the time it reaches your son's room.

    Please review the piping arrangements at the heating help site, scroll down to "loop hot water heating" and "diverter tee hot water heating" to review the piping arrangements installed in homes--see if you can determine your type of piping arrangement by looking at the pipes in your cellar.

    Please post back: with the room dimensions, heat loss calc, how hot the baseboard pipe is, boiler gauge reading & piping arrangement.

    http://www.bgmsupply.com/calculateheatloss.asp
    http://www.heatload.com
    http://hearth.com/calc/roomcalc.html
    http://www.heatinghelp.com/heating_qa.cfm
    Last edited by JacktheShack; 03-18-2008 at 09:30 PM.

  3. #3
    Join Date
    Mar 2008
    Location
    North West of Philadelphia
    Posts
    7

    Default Re: baseboard heat

    5/9/2008

    JacktheShack at TOH Discussions,

    The room is 18 foot long by 12 foot wide giving 216 Square feet. The amount of finned pipe is 9 1/2 feet on the long wall and 7 feet on the width giving 16 1/2 feet total finned. Taking 16 1/2 feet total finned times 500 give 8250 BTU's. The furnace is set at ~190 degrees at ~18 PSI. The room in question is on the second floor. Turning the thermostat up to 90 degrees on the second floor makes the copper pipe HOT within a couple of minutes. By HOT I mean you can NOT touch it. There are three vinyl windows in this room with Low"E"/Argon filled insulated glass. The long wall is an outside wall and has OK insulation. The width is mostly up against the unheated attic and has OK insulation. Being on the second floor the attic is overhead and has GOOD! insulation (now).

    If we use your, average, heat loss factor of 40 we have 216 Square feet X 40 = 8640 BTU/Hr. If we divide 8640 BTU/Hr by 500 BTU/Foot of baseboard = ~17 feet which is about what is there now. I'm thinking that with the insulation only being OK (It was good for a house built ~40+ years ago and I have found areas without ANY) the heat factor should be closer to 60 giving 216 X 60 = 12960 BTU/Hr / 500 BTU/Foot = ~26 feet of fin, there are 30 feet of outside wall. Maybe a "split the difference" of a heat loss factor of 50 would be "safer", we don't want to get the room too hot? So 216 X 50 = 10800 BTU/Hr / 500 BTU/Foot = ~22 feet of fins.

    Thoughts, suggestions, more questions?

    Thanks,

    RSCH

  4. #4
    Join Date
    Aug 2007
    Posts
    443

    Default Re: baseboard heat

    RSCH:

    Your calculations sound good, and I'm glad to hear that the water in the baseboards is HOT, HOT---this means you have good water circulation, & temps that high make it easier to heat the room.

    It's good stragegy to line both exterior walls with finned baseboard--it is amazingly easy to reduce the BB output if it gets too hot in the room by covering a portion of the finned elements with HD aluminum foil, or pink insulation (since it is behind the baseboard covers, it is invisible & out of sight)---another way of course, is to install a ball valve or radiator valve during the rehab to "throttle" part of the hot water from entering the room---but this is allowable only in piping arrangements that are NOT series loops (see previous post).

    From the way you describe the water, it's probably 180-190 degrees---this would equate to closer to 580 btu/hr heat output per foot of baseboard, instead of ~500.

    In any event, I would recommend you remove the "bare copper pipe" & replace it with finned baseboard elements---they are low cost, ~$.70/ft--usually come in 8' lengths/4 to a box, but can be bought individually at plumbing supply houses in your area.

    You will also need some steel brackets to hold the elements. copper elbows, couplings, etc.

    Post back if you intend to do the job yourself & you need more info as to how to proceed.
    Last edited by JacktheShack; 05-09-2008 at 05:59 PM.

  5. #5
    Join Date
    Mar 2008
    Location
    North West of Philadelphia
    Posts
    7

    Default Re: baseboard heat

    5/9/2008

    Yes I do intend to do it myself. Any words of wisdom, other then "are you crazy"? Any suggestions?

    Thanks,

    RSCH

  6. #6
    Join Date
    Aug 2007
    Posts
    443

    Default Re: baseboard heat

    RSCH:

    You can do it, we can help!

    Do you have any experience in soldering (also called "sweating") copper tubing???

    Do you have any equipment or tools needed to solder copper tubing, such as a small Bernzomatic trigger torch, solder, small tubing cutter, emery cloth, solder flux???

    Are there any friends, neighbors, or relatives who have done soldering who can help??

    Can you post any photos of the baseboard in your son's room??

    You can obtain all the low-cost supplies you need for this project at HD/Lowe's, or a local hardware store---you are much more likely to get "hands on" help from an owner-operated hardware store--the owner/clerk may be willing to demonstrate soldering 2 scrap pieces of copper tubing together while you watch, and even try it yourself, if you buy some of the supplies there.

    Google "how to solder copper tubing" and "soldering copper tubing", or "tips for soldering copper tubing" to get numerous sites, some have "how-to" videos; a few are posted below.

    It is usually possible to solder the tubing/finned elements at your workshop in the garage/basement, etc., where the pieces can be placed on a workbench---it's a lot easier to do most of the soldering where you can move the piece around, instead of crouching in a confined space inside baseboard covers.

    Once the soldered tubing cools at the bench, it is usually possible to air-test it for leaks before installing it onto the heating system.

    Please post back with info requested.


    http://www.graspr.com/videos/copper-tubing-projects
    http://www.associatedcontent.com/art..._tubing_ithtml
    Last edited by JacktheShack; 05-10-2008 at 09:32 AM.

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