At our office, we have a server room located on the southeast-ish side of our building, exiting onto a parking lot/loading dock area (a completely paved area with zero shade). The door is an emergency exit (made of steel I believe) with one of those bars you push to open the door. And the door is completely exposed to the sun for most of the day. The rest of the exterior wall is concrete. We keep that room closed because it contains sensitive hardware and some sensitive files.

On hot days (like yesterday), that door gets hot - like, you can't touch it with your hand hot. And the server room gets uncomfortably warm as well, because we have this metal door radiating into the room. And occasionally, we have hardware issues as well - we have a "disaster-proof" NAS in there that overheats and shuts down (because it's insulated to protect against fire damage). We do have a dedicated air conditioner in there which can usually handle the heat, but once in a while it just gets overloaded.

I should note that the landlord will not permit major renovations, and that's probably not an expense we need right now. Also, this happens maybe two or three times a year, so it's not a huge issue, but it would be nice to correct if we can do it inexpensively. I have thought about perhaps sticking some fiberglass insulation to the inside of the door, but that's going to be ugly, kind of messy, and probably not something management will go for. Something like styrofoam might work as well, but I suspect actual styrofoam would not be an adequate insulator.

Is there something we can do to cheaply and easily insulate the inside of that door so it's not radiating so much heat into the room?

  • Water cooling!!! :D just kidding. Expanded Polystyrene (EPS) panels are what are usually used for rigid insulation and are the sturdier cousin of the Styrofoam used as a cheapo cooler. A couple of pieces, one above the crash bar and one below would help, but I haven't a clue if that would meet code in a commercial building. (hence comment, not answer.)
    – FreeMan
    Jun 11, 2020 at 16:14
  • Foam board might be a fire hazard in and of itself if installed. If there is a fire, would you want to have to charge through a door covered in flaming melting plastic?
    – JRaef
    Jun 11, 2020 at 16:23
  • Could a structure be erected to shade the door? I am also unsure of code requirements, but a cheap canopy erected around the door may skate by.
    – Aww_Geez
    Jun 11, 2020 at 16:25
  • 2
    My experience with fire codes and fire inspectors is that they have little tolerance for anything that is not to their interpretation of the code. Before you do anything, check with the fire inspector.
    – jwh20
    Jun 11, 2020 at 16:41
  • 1
    Can you provide photos of the listing labels on both the door and frame please? The fact it's a metal door with panic hardware does not necessarily mean it's a fire door, and in this application (direct exterior egress), the door very well may not be; either way, having the landlord swap the door for a better-insulated one is probably the simplest option here... Jun 11, 2020 at 17:00

1 Answer 1


I think you only possible solution, that would not violate life/safety codes, would be to build a portico over the door outside to keep the sun off of it for as long as possible.

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The other option is to paint the door exterior with a special heat reflective paint. It is designed to reflect a lot of the infrared energy away from the surface it is painted onto. I have put it on steel shipping containers used as site offices, it is highly effective. It has no effect if painted on the inside, it has to go on the exterior. So both options will likely require some interaction with your landlord.

  • The portico should work; however, the heat-reflective paint probably would void the listing of the door IF it's an actual fire door, which it might not be, though... Jun 11, 2020 at 16:58
  • I don't think the listing of a fire door is affected by paint on the OUTSIDE, but it might on the inside.
    – JRaef
    Jun 11, 2020 at 17:07
  • Even a coat of white paint on the outside of the door would help...
    – Solar Mike
    Jun 11, 2020 at 20:43

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