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New addition/baseboards in an old house--balance

We are having an issue getting the copper/fin baseboards in our new addition to heat above 62 degrees, even with the thermostat set to 75 in the next room.

The house is single zone, two story, gas heat, boiler, cast iron radiator, hot water heated, with the thermostat on the first floor in the living room. The house has no insulation in the walls, but for new siding and tri-fold outside. Attic and basement are well insulated. The addition is a first floor family room, 260 sq feet, heavily insulated, and presently closed off with the old french doors during construction. The contractor had two 8 foot baseboards installed in the addition. System is well bled. The baseboards do not heat the room above 62 degrees. The heating contractor wants to simply balance through manual valve adjustment of the cast iron radiators (turning them down so less water flows through). He says this will be more efficient than adding a second zone for the addition. I am looking for advise as to whether this is the best course to go.


  • Rich_49
    Rich_49 Member Posts: 2,766
    What are

    the heat loss characteristics of the new room ?  We need dimensions , length of exposed walls and what windows/doors are in those walls , ceiling height , heated above and/or below , insulation values in walls , ceiling , floor .  This room being in a home that has radiators to start with sounds like a great place for panel rads . Can't tell anything without the above information however . Also where are you located ?
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • BuffaloBill
    BuffaloBill Member Posts: 5
    Response to your request re heat loss characteristics

    Thanks for the response. The addition is one story, sloped/flat roof, four foot crawl space, insulated, 2x6 walls, 2x12 floor and ceiling. Batt insulation throughout. Dimensions are 14 x 20, 8.5 foot ceiling, two Andersen windows and one sliding glass door on the exposed 20 foot wall. I do not know the energy star ratings as I type for these, but know they qualify for the tax credit. Three exposed walls--the two 14 foot and one 20 foot walls. The addition and house are sided with tyvek, 3/8 tri-fold and certainteed perfection vinyl "cedar" shake siding. The contractor had two six foot copper/fin baseboards innstalled on the exposed wall under the window. With the french doors closed (pending finish work--they will be removed) the room heats to 62 with the thermostat in the next room blasting at 75. We live in Buffalo.

    The heating contractor suggests balancing the radiators with the baseboards after the space is opened. I think he means to simply partially close the valves on the radiators throughout the rest of the house He said if that did not work, he would install a second zone, which was my thought.
  • kcopp
    kcopp Member Posts: 4,431
    Part of the....

    problem is there are 2 different types of radiators. Cast iron and copper fin tube don't mix well on the same zone.

    copper heats up fast and cools fast ...CI slow and slow.

    The heatloss I ran through is around 7800...making a couple presumption as to window size and what is above and below your floor.

    A separate zone may be better. You may be a bit shy on baseboard.

    One thing to also figure is the constant breeze off the lake there.  My son attends college there and I have spent a few cold days there watching ball in the spring.
  • BuffaloBill
    BuffaloBill Member Posts: 5
    Thanks for confirming

    the two zones, which is what I thought would be needed. It does get windy in the winter. I have had the french doors opened all night and the addition has warmed to 65 vs.72 in the rest of the downstairs.

    I also thought 12 feet of BB was a little light, but wonder even if he put in another wall of it, if the copper/fin would be consistent with the thermostat cycling based on the cast iron in the rest of the house.
  • kcopp
    kcopp Member Posts: 4,431
    adding fintube.....

    prob will not help a whole lot as far as balance goes. Is there a basement underneath? Making changes now could be a real challenge if not. You could get a couple cast iron rads off craigslist and install them. I am surprised that there is a hot water system in your place. most everything I have seen there is FHA.

     Go Griffs!
  • BuffaloBill
    BuffaloBill Member Posts: 5
    crawl space

    there is a 4 foot crawl space, insulated, with a 4 foot opening to the basement. And you're right, mostly forced air up here, which would be more convenient in this situation, and to add central air, but you play the hand you're dealt I guess.
  • why??

    Why use more pitful copper fin tube radiator?? Go with better comfort using cast iron baseboard radiator.. on its own zone.. pricey but better comfort
  • Steamfitter66
    Steamfitter66 Member Posts: 117
    edited November 2013
    Cast Iron and fin tube dont mix

    I learned this the hard way 20 years ago. they work at different water temps and the cast starts its heat output at 100* and baseboard needs about 140* to start. impossible to balance.

    Has the contractor done a heat loss on the house both old and new? its the only way you can accurately size the radiation for the addition.

    If a heat load is done you may find that its not that expensive to go with cast iron. Its much nicer to live with.
  • BuffaloBill
    BuffaloBill Member Posts: 5
    Sort of far along to change to cast iron now, I think

    Had I known before I got into this, I would have found some cast iron or asked for radiator panels, but didn't start to ask the hard questions or do my own research until we put a thermometer in the addition after it was sheetrocked and spackled and lo. The contractor agreed to try 8 more feet of baseboard with a second zone/thermostat. The extra baseboard is in; and the heating guy is going to do the second zone after Thanksgiving. The room is up to 68, and its about 20 degrees outside now. So we are getting close. I hope. Thanks for the comments. Happy Thanksgiving.
  • Weezbo
    Weezbo Member Posts: 6,232
    Habby thanksgiving

    the place is warmer and thats a plus .


    balancing one with the other is not quite as simple as it seems , that is why folks were saying iron baseboard would be a better match .

    still, that you are more comfortable this Thanksgiving is a good thing ...

    May the blessings Be.

    *~//: )
This discussion has been closed.