Mini radiator for bath remodel

Discussion in 'Boiler Forum' started by jim mills, Feb 3, 2014.

  1. jim mills

    jim mills New Member

    Messages:
    141
    Location:
    nebraska
    Help! Planning a main bath remodel for a 1920's house with a single pipe steam heat system. Bath has a large radiator in it that we would like to remove. What options are available that would allow us to use the available steam, without the large radiator taking up space?
  2. Dana

    Dana In the trades

    Messages:
    2,803
    Location:
    01609
    All good solutions are going to start with a room-by-room heat load calculation, which will determine the zone balance and the minimum size steam radiator that will work. If part of the remodel is to air-seal and insulate the exterior walls and install high performance windows you may be able to skip the radiator entirely. (You may also be able to run it as it's own zone using pumped hot water radiation rather than the steam, but that would run counter to your stated desire to use the available steam plumbing.)

    Cast iron baseboard often works well in bathrooms- just be sure to not install baseboard radiation directly behind/under the toilet. It comes in a number of different heights, with different BTU/linear foot or equivalent square feet direct-radition per foot ratings, and is period-appropriate if you're trying to preserve the 1920s craftsman-look:

    [​IMG]

    Small thin profile wall-cut-in type radiators like the classic Sunrad, or Burnham Radiant can also work well, if that's a better fit. They're about 5" deep, 20" tall, and come in any number of widths:

    SunRad
    [​IMG]
    SunRad




    Radiant
    [​IMG][​IMG]
    Radiant

    Be sure to insulate VERY well if putting it on an exterior wall. (Thinning out the framing to 2.5", compressing in a snug-fitting R11 batt into that 2.5" depth, then adding 1-1.5" of foil faced rigid polyiso on the interior side as a thermal break on the studs keeps it from sending 15% of the heat outdoors.)
  3. jim mills

    jim mills New Member

    Messages:
    141
    Location:
    nebraska
    I have seen a toe kick heater & was hoping that something like that would work, but I found out they are forced hot water, not steam. I hear you can run forced hot water off a boiler using a heat exchanger, but way too complicated & costly for this application. Actually, that baseboard heater in your first picture might just be the perfect solution. Is ther an issue having it too close to the toilet though?
  4. houptee

    houptee Member

    Messages:
    182
    Location:
    Monmouth County, NJ
    Too bad your not near NJ i have a bunch of cast iron rads and baseboard sections I took out after Sandy flooded my house. They will probably end up going to the scrap yard since nobody seems to want them. They have been outside so they rusted but could be sandblasted and repainted.
    If you look on craigslist you might find some radiators near you for sale cheap.
  5. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
    3,929
    Location:
    North Vancouver, BC
    http://www.oldcastironradiators.com

    I bought mine all brand new from this place.

    http://www.oldcastironradiators.com

    They have loads of sizes and options for you to try out. They ship anywhere I'm told. One in three rads in North America originally come from this family owned company. The moulds are the same today as they where 100 plus years ago.

    [​IMG]


    [​IMG]

    I have the 4 column #29 in my home
    Last edited: Feb 5, 2014
  6. jim mills

    jim mills New Member

    Messages:
    141
    Location:
    nebraska
    Thanks John. I'll check them out. The problem is the existing radiator sits right next to the tub, taking up about 3' of wall space. Then sits a pedestal sink, then the toilet. They want to remove the radiator & put in a 60" vanity. Makes sense, six kids & a pedestal sink don't cut it...
    bath.jpg
  7. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
    3,929
    Location:
    North Vancouver, BC
    Maybe you can design a bench of sorts and cover the new Rad. Somewhere to put some baskets and some crap for the family.

    ???

    Make sure you clean the connection threads well when you hook up the new rad. I had a few poor connections I think because I didn't do a good job of cleaning these dirty threads. Ran the system in my garage for a few weeks to monitor the rads before hooking a few up. Love the heat and the look of them.
  8. DonL

    DonL Out of the Trades

    Messages:
    3,898
    Location:
    Houston, TX

    Just looking at them make me miss my grandparents.

    This is more my speed.

    TRD40615T.jpg
    http://www.delonghi.com/en-US/products/comfort/portable-heating/radiant-heaters/
  9. Dana

    Dana In the trades

    Messages:
    2,803
    Location:
    01609
    The issues with putting steam baseboard radiation directly under/behind toilets are twofold:


    1: The toilet can heat up to a very uncomfortable temp during cold weather (or during recovery from setbacks) when the duty cycles on the heating max out.

    2: The overly-warm toilet causes the seal to the drain to fail (and the traditional wax seals can melt entirely!)

    Even though it's traditional to put the radiators under windows (a practice begun back in the day of leaky single-panes, that collected copious frost/condensation otherwise), it looks like you have sufficient wall length between the door and the right side wall to put cast iron baseboard opposite the toilet & sink, maybe even turning the corner, stopping before it's even with the toilet. Whether that's easy or difficult to implement the way the current steam plumbing is currently routed under the floor isn't obvious. The two biggest vendors of c.i. baseboard are Burnham ( the product line is called "BaseRay"), and Weil McLain (called "Snug".) The ~8"-9" tall versions have comparable output-per-foot to 2" fin-tube type baseboard, but since a large fraction of the output is radiated rather than convected (almost all fin-tube output is convected air) it's noticably more comfortable.

    Heat loads of bathrooms are pretty low- the size of the radiation needs to be reasonaly balanced with the radiator sizes relative to their room loads on the rest of the system though so that you neither overheat or under heat the bathroom relative to the rest of the house. If the existing radiator is sized with reasonable temperature balance, you can measure it up to determine it's "Effective Direct Radiation" (EDR) size which can be applied to the EDR of the new radiator or baseboard. It doesn't have to be exactly the same EDR as the original radiator but keeping the new radiator neither more than 1.5x nor less than 0.5x would be prudent, if it's working OK now.
  10. johnfrwhipple

    johnfrwhipple I love these ACO Shower Drains - Best in Class

    Messages:
    3,929
    Location:
    North Vancouver, BC
    Jim if you work out the heat calc for the room you can call the company I mentioned and they will tell you what unit you need. My kitchen is huge with 3 5'x3' windows on the South wall

    1 single lite french door 1 5'x3' window and 1 3'x2' window on the West Wall and I have only two rads.

    Both 4 fin. One 20 stacks one 8 stacks.
  11. jim mills

    jim mills New Member

    Messages:
    141
    Location:
    nebraska
    Thanks Dana. The reason I asked about a radiator behind a toilet is that your first picture shows a radiator beside a toilet. I couldn't understand why this would work, but not behind. I will be turning this over to the boiler man soon, but want to be as informed as I can be before I do.
  12. Dana

    Dana In the trades

    Messages:
    2,803
    Location:
    01609
    When the radiator is behind the toilet the convecting air column is impeded and more of the heat ends up in the toilet, (including the water in the tank). A foot or so of clearance (just a WAG) to the side should be sufficient space that the toilet itself can convection-cool enough from it's absorbed radiated heat to keep it from getting too far out of hand. Tucked in there as in the picture it still might not be the most-comfortable under high heating duty-cycle conditions, but it probably won't melt the wax seal.

    FWIW: In my own home in a tiny upstairs bathroom I have a section of Weil McLain Snug on the wall behind the toilet that extends ~1/3 of the way under the tank, but not behind the bowl. But it's a pumped hot water system @ 130F max water temp, not 220F steam. Even that bit warms the toilet enough to be noticed by the user, but not enough to lead to discomfort. I haven't measured the actual toilet temp, but it's probably hitting around 80-85F. Even 25F warmer would be uncomfortable to sit on.
    Last edited: Feb 6, 2014
  13. emmet_97

    emmet_97 New Member

    Messages:
    1
    Location:
    NJ
    I am in NJ and looking for replacement sunrads. If you can help it is appreciated

    I am in NJ and looking for replacement sunrads. If you can help it is appreciated
  14. CanOfWorms

    CanOfWorms Member

    Messages:
    174
    Location:
    New Jersey
    Try this. It looks great works great and is something you can brag about.
    If you use 3 x 3' sections you just added 12' of baseboard
    radiator loop.png
  15. nhmaster3015

    nhmaster3015 Master Plumber

    Messages:
    836
    Location:
    The granite state
    You can pull a hot water loop off the bottom of the steam boiler. You need a circulator and an aquastat.
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