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How do you INSULATE above a Trane Concealed Heater?

Rocknut Member Posts: 4
edited January 2022 in Strictly Steam
Wisconsin sure is COLD🥶 Have Trane’s “unobtrusive & revolutionary” Heat Convectors in my 1933 home and they work great! The large front window in the living room has a handsome 18” deep wooden window sill with a Trane heat cabinet hidden beneath. Other rooms have Trane’s Concealed Heaters in the wall.

For over 20 years, there has been a perennial ice dam problem along the front north-facing roof line. The ice thaws by March and lands on the driveway. It can be a solid ice slab 6’ X 3’ X 1’ !

In January I am finally having some weatherizing work done focused on the north-facing roof line to prevent the ice damming. Uninsulated knee wall closets will get closed cell spray foam insulation to create a thermal barrier (hot/cold) air barrier.

The north facing bedroom above the attached garage has a Trane’s Concealed Heater unit directly beneath a window.
The contractor asked if the Trane unit could have insulation put above the vent grill. The heat is escaping out to the edge of the roof.

Issue : The bid states “We will attempt to gain access to the area below the dormer with the boiler register. If possible, we will insulate the sloped area; this will be determined on-site by the production crew.”

Question: Can they put insulation above the vent grill?

Hope you will share your knowledge and wisdom! Thanks so much!
Al Brown

ARTICLES on Trane from Wisconsin Historical Society.




  • Rocknut
    Rocknut Member Posts: 4
    Why no comments? Help, please🙏
  • ethicalpaul
    ethicalpaul Member Posts: 5,703
    I tried to picture what you're describing and couldn't. Could you include a photo or drawing of where you're trying to prevent the heat from going?
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • mattmia2
    mattmia2 Member Posts: 9,660
    You just want to insulate outside the cabinet, right? It should be able to use pretty much anything, the outside of the box at worst will get to steam temp of about 210 f.
  • Rocknut
    Rocknut Member Posts: 4
    Thank you for your comments - here are a lot of photos.
    What is the best tape/caulk to seal the lining prior to insulation?
    Exterior pix shows ~16” of roof below the window, given access to this space, will blown in insulation keep the heat inside? Help to prevent ice damming?
    When inspection confirms the lining is asbestos :(, what are the next best steps?
    Anticipating a possible answer, what is the best paint to encapsulate asbestos?

    Sure do appreciate all your recommendations - your knowledge & wisdom is greatly needed!

  • BobC
    BobC Member Posts: 5,478
    To me that lining looks like Homasote which was popular back then. it was a 1/2" paper product often used in utility areas because it was one of the cheaper sheet goods at the lumber yards. As for sealing the seams any acrylic caulk should do. Just wipe the seams with a damp cloth first to remove any dust.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • mattmia2
    mattmia2 Member Posts: 9,660
    edited January 2022
    I'd test it, it doesn't look like it is primarily asbestos but they liked to add it to just about everything fiberous.

    If you can get to the back, spraying it with spray foam, if you can find one rated for the temp and to be left exposed, will seal up the air leakage of that box.

    My preferred caulk is osi quad although any caulk may have trouble adhering to that homosote. Make sure you really force it back in to the joints.
  • PC7060
    PC7060 Member Posts: 1,160
    edited January 2022
    Fresh OSI quad; look at date on tube when buying.   Stuff gets hard to work with pretty quickly. 

    Re the foam sealing recommended by @mattmia2; he is right on but do yourself a favor and buy one of the guns from Amazon and use the pro cans which are easier to work with and last much longer. 
    I’ve found this gun to be very reliable. 

    You can buy the GREAT STUFF PRO Gaps and Cracks 24oz cans at Lowes or Home Depot for around $11. 

    Just leave the can on the gun when not in use, no need to clean after each use. Lasts very long time. 

  • Rocknut
    Rocknut Member Posts: 4
    Thank you for your very quick responses! I’ll check out Homosote. Great feedback!