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Retrofit radiant heat under wood floors

user-5868846 | Posted in Energy, Heating & Insulation on June 27, 2004 02:45am

I need help designing a radiant/hydronic (?) floor heating system for a 1200 sq ft 1 story bungalow (95 yrs old) on Long Island, mediocre insulation, 50% basement/50% accessible crawl space.  2.25″ oak floors some on 1×6 pine some directly on joists, no carpet, a couple area rugs (15% of total floor), several built-ins against outside walls as well as a relatively cold galley kitchen. The current system is a noisy forced hot air with leaky ducts congesting a low basement ceiling, which will eventually be finished.  I have 20 yrs construction experience including plumbing & baseboard heat but no experience in installing radiant under existing wood floors.  Is there a comprehensive book I can get? I have questions about: 1) Heat source 2) Tubing size, length, and loop config. 3) Proportioning valves/manifolds 4) System sizing 5) Running, hanging, reflecting & insulating Pex tubing 6) Code considerations.   Any help would be greatly appreciated. Thanks, T-


Edited 6/27/2004 9:49 pm ET by Terence5

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Replies

  1. dovetail_inc | Jun 27, 2004 06:32am | #1

    i installed a radiant system in our new home in southern new jersey using heatway products.  the tubing was stapled under the 3/4" df plywood subfloor in very specific

    patterns. left a 2" air space w/ foil backed  r-22 insulation below  between joists. finished floor was 2 1/4 " quarter sawn white oak stapled directly to fir subfloor.  heating season shrinks floor acceptably.  we open the windows in the spring and

    the body of water one block from our home refered to as the atlantic ocean i assume is responsible for eliminating all gaps between floor boards in 48 short hours! amazing! used an awesome w.mc. gv3 gold boiler. lots of thought in the layout,

    used  a great plumber, ran all the tubing myself (builder), would never own aother

    home without radiant floor heating. call bridgeton plumbing supply in bridgeton. n.j..

    ask form dave.

    1. user-5868846 | Jun 28, 2004 07:11pm | #5

      Thanks for the help Tom.  Is the Wiel McLain boiler tankless?  How many BTUs is it?  How many sq ft is your house & is it tight? Was the system installed in new construction & is the oak floor new?

      1. dovetail_inc | Jun 29, 2004 03:46am | #7

        its a gold gv 3 70,000 btu/hr boiler w/ an indirect fired water heater.  all new

        construction, 2x6 r-21 walls super tight all around. the oak floors are quatersawn

        which i would strongly reccomend to reduce shrinkage during heating season. our

        home is about 2400 sf. tom.

  2. Piffin | Jun 27, 2004 07:01am | #2

    http://www.google.com/search?hl=en&ie=UTF-8&q=Earthstar+%2B+radiant+heat&btnG=Google+Search

     

     

    Welcome to the
    Taunton University of
    Knowledge FHB Campus at Breaktime.
     where ...
    Excellence is its own reward!

    1. jjwalters | Jun 27, 2004 02:48pm | #3

      Piffin ...What do you think of the electric radiant heating system as a primary/secondary source in a 1200sq ' cabin?

      Sounds good to me, but wonder what the monthly bill would be between that and baseboard?............

      1. Piffin | Jun 28, 2004 02:58am | #4

        most banks and insurance companies require a system other than wood only to approve financing.

        EWlectric baseboard heat is cheap to install but expensive to run. and people are basically lazy enough that most do not rely on the wood heat sao the expense of the elec BB means that eventuallyu, tjhey rip it out and send it to the dump 

         

        Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

  3. csnow | Jun 28, 2004 09:32pm | #6

    For radiant, this is THE book to get.  Siegenthaler rocks.

    http://www.hydronicpros.com/Publications/MHH2/MHH2.htm

    1. user-5868846 | Jun 29, 2004 05:06am | #8

      Thanks for the tip. I couldn't get it at the library but saw it at the book store the other day for $100.  It looked like the difinitve authority on water heat.  I'll try to get it used online.  T-

      Edited 6/28/2004 10:19 pm ET by Terence5

      1. csnow | Jun 29, 2004 04:29pm | #9

        You should be able to get it for closer to $75 net.  It's pretty new, so there will not be many on the used market yet.  Even comes with nifty software.

        Try:

        http://www3.addall.com/New/submitNew.cgi?query=0-7668-1637-0&type=ISBN&location=10000&state=MA&dispCurr=USD

  4. User avater
    johnnyd | Jun 29, 2004 06:38pm | #10

    Try hanging out here from time to time.  You'll learn alot.

    http://forums.invision.net/index.cfm?CFID=667189&CFTOKEN=1ef2b88-e9f12e1f-5ee3-4cdc-a0ee-40fba5a0cf6a&CFApp=2&

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