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Creating multi zone heating

I have an 80 year old house with steam heat. The house has about 12 radiators covering 3 floors with only one zone. Is it possible to convert the system to a Multi zone system keeping the exsisting radiators and furnace? I would like to have at least 2 zones. Is that a costly job? Thanks.


  • Rod
    Rod Posts: 2,067
    Use TRVs

    Hi-  What are you trying to accomplish by zoning?   You can do a fair amount of "zoning" with TRVs (Thermostatic Radiator Valves) I also have a 3 story house and in the winter, to save fuel, we shut down a lot of the house using TRVs.  The 3rd floor is kept at around 45 degrees and the other rooms on the 1st and 2 nd floor that we aren't using are set to around 55 degrees.  I like to sleep cooler at night so I set  the TRvs in the bedroom to about 55 degrees and then turn them up in the daytime to 68.  The rest house it controlled by the thermostat. TRVs won't increase the heating but will control overheating.

    - Rod
  • Jamie Hall
    Jamie Hall Member Posts: 22,174
    TRVs are indeed...

    the way to go for this.  Which is not to say that you can't zone a steam system -- you can.  However, it is a little trickier than meets the eye.  You need to be very careful that you don't cut off needed vents, and that when the zone valves are closed that you are left with adequate venting.  Second, you need to be sure that any returns (wet or dry) will function properly (they may not need to be valved, but that needs to be checked) and that both sides (repeat: both sides) of any zone valves are dripped to a wet return.  And last, any zone valves used must -- no choice in the matter -- be full port ball valves.  You cannot use a reduced port valve in such an application at all, and gate valves often don't work well (globe valves, needless to say, are an absolute no-no).
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Skater
    Skater Member Posts: 2

    I would like to install a two zone central A/C system but keep the steam heat. I like it better then forced hot air. I like the idea of dual zones, to save on my heating bills. Do a lot of people keep the old steam heat when they install central air to older homes?
  • jpf321
    jpf321 Member Posts: 1,568
    edited December 2011
    what you need are ..

    e-TRVs like I have in my house ..

    + each Radiator has the ability to CALL for heat (act as thermostat) AND limit heat (act as TRV).

    + each rad can be programmed up to 8-slots each day of week .. and each rad can have its own "swing" setting.

    + the whole system is run wirelessly by a central laptop .. the boiler portion is connected in parallel with existing thermostat onto "TT" (24v)

    + the e-TRVs screw onto the end of the rads where your Air Valve is currently and then the air-valve screws into the e-TRV.

    + since all they are doing is controlling the vent opening (either full open or full closed) on each rad, there is little you need to be too concerned about except for breaking vacuum at end of cycle .. which they do automatically.

    if you want more information, contact me directly.

    1-pipe Homeowner - Queens, NYC

    NEW: SlantFin Intrepid TR-30 + Tankless + Riello 40-F5 @ 0.85gph | OLD: Fitzgibbons 402 boiler + Beckett "SR" Oil Gun @ 1.75gph

    installed: 0-20oz/si gauge | vaporstat | hour-meter | gortons on all rads | 1pc G#2 + 1pc G#1 on each of 2 mains

    Connected EDR load: 371 sf venting load: 2.95cfm vent capacity: 4.62cfm
    my NEW system pics | my OLD system pics
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