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Adding Radiant heat to a 1 pipe steam system

FMA124 Member Posts: 17
Hello all - I am buying a 1950's cement house, I mean the floors on the first and second floor are cement slabs as well as the basement, and the house has a 6yr old steam Burham boiler. The house does have a seperate hotwater heating zone for a sunroom, which is set up with a Heat Exchanger.  I am going to remodle the whole house and add rooms upstairs so not sure how easy it is to move around the radiators with steam.

Since I have cement floors with plenty of headroom I was wondering if it made sense to install radiant tubes as either a suplement or to eleminate the radiators for heat. Can this be done with the same steam boiler? Is it just a big waste of $$ in your options?

Also, does it make sense to shut down a steam boiler for the summer and get a hotwater tankless system or get an indirect hotwater tank?

Thank you for the help!!!


  • FMA124
    FMA124 Member Posts: 17
    Any help is appreciated....

    Any help here is appreciated... How hard is it to expand a Steam heating system? Can I move a radiator from one side of the room to the other by just running the pipe along the wall? Can I T off a current radiator and add more radiators?

    Thank you for the guidance..
  • Jamie Hall
    Jamie Hall Member Posts: 23,543
    Well let's see here...

    Adding radiators in general.  That depends on the size of the boiler in relationship to the existing radiation.  Steam boiler capacity is measured in EDR, and each radiator has an EDR associated with it, depending on the size of the radiator.  If you add up all your existing radiators, or the ones you want to keep, and than add in the EDR of the new ones, and the total is less than the capacity of the boiler -- no problem.  Although if the boiler has been down fired, you may have to bring it up closer to its rated capacity.

    Adding raditors to a specific pipe, particularly in one pipe systems, is a little more problematic.  You have to figure the total EDR on that specific pipe, and then refer to tables to see if the specific pipe size you have feeding the collection is big enough.  If it isn't, you will have problems.  You should get a copy of the Lost Art of Steam Heating, available from this site, which has all the tables you need in it.

    Moving a radiator isn't a problem, again providing that the pipe feeding it is big enough and can be pitched properly.  Again, the tables needed are in Lost Art.

    Radiant heat from a steam boiler is another story, however.  It may well have the capacity to do the job.  However, steam boilers run at steam temperature -- 212 -- while radiant floors normally run at much lower temperatures -- 140 or less.  There are ways to get around this problem using indirect hot water tanks, but they can be a little complex both to install and to control.

    Is your steam boiler also your domestic hot water heater?  If so, you could substitute a self-standing hot water heater and shut off the boiler in the summer.  Whether you would save any money doing that is another question entirely...

    Hope this helps.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Rod
    Rod Posts: 2,067
    Additions to Your Steam System

    Hi - Jamie has given you some really good answers to your questions. It can be done but it needs to be very well thought out first as there are a lot of calculations and requirements to be considered. Jamie mentioned getting the book, "The Lost Art of Steam Heating" which is available on this website at this link: http://www.heatinghelp.com/products/Steam-Heating-Books/25/68/Lost-Art-Of-Steam-Heating

    It's written so that the homeowner or pro, new to steam heating can understand it and will give you all the info you need to figure out the changes you want to do in your present steam system. Also look in the Resources and Systems sections at the top of this page as there is a lot of good info available on steam and hot water / radiant systems. Once you have a better understanding of steam and hot water /radiant systems, you'll be in a better position to make a decision on what needs to be done.

    - Rod
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