We just finished building a home, and I prewired an equipment closet upstairs for handling all of my networking, home theater and whole home audio equipment. It looks like this:

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All the single and double gang boxes are standard open-backed low voltage gang boxes, and the triple gang is a normal Carlon high voltage box. The back of this wall is attic which makes getting to things to wire them up a breeze, but also means that it's getting incredibly hot in the closet.

There's insulation on the walls that I cut away a little bit to pass wires through, and I've stuffed insulation in the low voltage holes where possible.


Even with the insulation, the outlet covers themselves are probably about 90-95 degrees on a hot day (110 or so in the attic). What are my options for insulating the low voltage brackets? Cramming insulation in there seems to be doing very little.

I know on the Carlon triple gang I can use expanding foam, but I'm a little hesitant to do that until I'm absolutely positive I won't need to make any adjustments to the speaker cable. Do I have any slightly less permanent options there that will still improve insulation?

  • What does "cramming insulation in there" mean? You can probably just hang a second layer of batts over the whole works and be happy.
    – isherwood
    Jun 10 '19 at 16:29
  • On some of the low voltage brackets, the insulation guy cut the batt around the gang boxes, and on others they just cut a flap to fold it over the back of the box. In the upper right corner you can see where there's no batt hanging over the box and I stuffed a 6" x 6" square of insulation into the gang box. I've done that on a couple of them. It hasn't seemed to make much difference.
    – Mordred
    Jun 10 '19 at 16:33
  • The one going in the fuzzy hole, that's not a mains power cord, is it? Jun 11 '19 at 10:56
  • @Harper If you're talking about the double gang pass-through, that's an HDMI cable. I have properly installed wall outlets behind every piece of equipment that needs it. I used the passthrough because all my research showed that adding an HDMI connector was going to be bad for/break 4K HDR/ARC.
    – Mordred
    Jun 11 '19 at 15:51

There's no harm in using more insulation than you technically need, and it's cheap. I'd do one of these things:

  • Hang batts vertically over the wiring; tack them along the top (and maybe at the the bottom depending on what's down there) and let them bulge out over it all. As long as they fit snugly together they'll do a fine job. There cannot be gaps or it does almost nothing.
  • Frame out an offset wall and move the insulation to that (or just add more and leave the existing). You could leave yourself enough space to get in an do later wiring work.
  • Due to the location of the roofline and roof supports, there's not any room for an offset wall (which would have been ideal). Hanging an extra batt seems like a really simple and effective solution though.
    – Mordred
    Jun 10 '19 at 16:54

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