I am just doing GOM & Linacoustic on the bottom half of my walls, and the tops will be painted. My in-wall rack is about 4' tall, and it will span both part of the walls that is covered with GOM, and part that is painted. I put a bathroom fan in the closet behind the AV rack to cool the equipment. Now I need to find a good place for the air intake into the closet. The best idea I have thought of so far, I think, is to cover the bottom part of the door with GOM to match the walls, and leave some of the door so there is just GOM there. No wood, no Linacoustic, just the GOM. My thought is that air could flow into the rack right across the equipment and then be sucked out by my bathroom fan in the ceiling. Do you think GOM is pourous enough the allow enough air to flow through to cool my equipment?
Good questions! There is a research paper here where the pressure drop through 3 different types of textile were measured. The results seem to show a pretty minimal pressure drop across the loosely-woven fabrics for flow rates in the range of what you would probably be using.
If their data hold true for GOM, you'd be looking at only 1-2 mmwc pressure drop for 100 cfm flowing across a 4" by 10" area.
If worst comes to worst, you could always assemble it and measure your air flow. If it is too low, cut away the GOM and install a nice-looking register.
I don't follow your setup. I'm picturing the air flowing from your theater, through/over the components in the rack, to the closet behind - then venting to your attic. How does the separate vent in the bottom of a door factor in?
Yeah, I guess I wasn't clear which door I was talking about. See the picture below, it shows everything. In this picture the unpainted (white) part of the wall will be covered by GOM. I'm hoping to build a cabinet door for the rack and cover at least the bottom part if not all of the door with GOM. The bathroom fan in the ceiling of the closet would suck air through the GOM in the rack door, and blow it out the hole you can see above the closet entrance door.
OK, so the "door" referenced is the cabinet door you are planning on to cover the components - not the door into the closet? That makes more sense.
Not sure how much airflow you'll get from a bathroom fan, but the better the airflow, the more the GOM will act as an air filter. Unless it is washable (thoroughly) it will either need to be replaced occasionally, or you will likely gradually see a color change in that cabinet door panel as the light dust begins to accumulate.
You see, that's what's so great about AVS. I thought I had a great idea, when it turns out it was a terrible idea. Thanks to your help I find that out before I implement it, rather then while watching movies wondering why there is a brown dusty square on the rack cabinet door, and all my equipment is overheating.
So it looks like I'll just plan to put a register grill of some sort in the cabinet door instead.
Correct. GOM makes a nice non-replaceable air filter! Never require HVAC air to flow through such fabric.
Unfortunately I have no choice as my right speaker area of my stage front is directly below a set of water pipes that go to my kitchen sink upstairs. The problem is that my builder thought it was a good idea to over hang the kitchen cabinets 2' out from the foundation. The pipes freeze every winter when the temperature gets down below 10 degrees if it is windy. I can not get to the pipes to wrap heat tape to them. I found that the only way I could prevent this is by removing all the insulation and leaving the joist bay open to the warm air in the basement. It has not frozen in a few years now that I have done this. Now that I am finishing off the area, I ran an HVAC output duct to that bay and pump warm air directly in there and then let it cascade down into the speaker area through the GOM cloth. Hopefully since I am blowing out through the fabric instead of sucking in through it and the fact that I am directly after the high efficiency filter I should not have too many problems. Obviously I will only leave the damper open during the winter months.
Depending on how you populate your rack, and the look you are going for - another possibility is to put a cabinet door over the top half hiding the shelves full of accessories, remotes, DVDs, etc. and leave the bottom with the components open.
Without a rack with faceplates, that may not be as clean a look as you are going for.