Unfortunately, the only place we can have a sofa is in front of the radiator and the radiator cannot be moved. I am thinking about building a box around the radiator to achieve the following:
The Goals

  1. Keep heat away from the back of the sofa. (It's a leather sofa to looking to avoid drying damage)
  2. Try and direct as much heat upwards and into the room

The box specification:

  • Bottom of the box fully open
  • Gap around the front and sides of about 50mm
  • TRV to be outside of the box and not behind the sofa as much as possible
  • Top of the box to have plenty of holes or slots
  • Box made from 12mm MDF

For lining the inside I am thinking of one of the following:

  • Thin sheet of Celotex (or other branded). I think the thinnest is 12.5mm
  • Insulated underfloor lining


  1. Will this design help with The Goals?
  2. What is the best material to line the box with to keep heat from escaping from the front & sides?
  3. What other things would you suggest to help achieve The Goals?


  • What kind of radiator: tall cast-iron, or long baseboard? Commented Dec 17, 2020 at 17:22
  • A standard steel panel radiator. toolstation.com/…
    – IamOnStage
    Commented Dec 17, 2020 at 18:54

2 Answers 2


As an alternative, requiring rather less work, how about this:

  1. get some sheets of rigid insulation such as is used in places like ceiling over a furnace (also fireproof but you don't care). Attach these in an unobtrusive way to the back of the sofa.
  2. place some wooden blocks between the radiator (or wall) and the feet of the sofa to act as standoffs.

This way the radiator has plenty of room for convection and the sofa is fully protected.


One thing to keep in mind with the placement of furniture and/or radiator covers is that cast iron radiators heat by radiation (think of the suns heat) and convection. Placing anything in front of a radiator lessens the feeling of warmth since the radiation part of the heating is removed or decreased. That being said there have been many writings as to the affect of radiator covers on increasing or decreasing the heat output of covered radiators depending upon the design of the cover. Before proceeding I would "google" to look for suggestions and remember that if you cannot get the room warm, it may be the radiator cover. my 2 cents.

  • Yeah, hot air naturally rises, but, with a normal radiator, some heat will come off the sides & bottom of the radiator to warm near floor level. This insulated box will direct the heat to the top of the sofa, and it will all rise from there, cutting off the ground flow. Sometimes you've gotta do what you've gotta do, but it will likely make the room feel colder because of the loss of lower level heating.
    – FreeMan
    Commented Dec 17, 2020 at 17:12
  • 1
    The insulated box will be blocking this heat, but the heat is being blocked anyway by a massive sofa, which will actually absorb more heat than an insulated box with open top and bottom.
    – IamOnStage
    Commented Dec 17, 2020 at 18:52

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