John Sayers' Recording Studio Design Forum Archive

In those "air tight" rooms where air supplies and returns are placed and especially those with air supplies but NO returns, I have seen where if you open a door there is a "sucking-rushing air" flow that occurs.
I would think if there is an adequate return air system for the room, the room won't be pressurized to release air "as much" when a door is opened.

My concern about this action is this: By having acoustic treatments with different types of insulation (Roxul, "Pink Insulation" etc.) with loose fibers, those fibers are said to be ok as long as they are not disturbed. (BTW-I also saw Rod's post in the reference section concerning info about insulation from the American Lung Association) But, in a small room such as a vocal booth or a small control room, when a door is opened, the pressurized rushing air evacuating the room my have enough energy to move those fibers that may be located all around a room in clouds, absorbers, traps etc.

Does anyone have any 1st hand knowledge on this or have been in a studio where this "sucking" action occurs? Do you see the cloth on any acoustical treatments moving? Possibly dust/loose fibers stirring in the air?

Is it possible that for all clouds, absorbers, traps etc with "tight-knitted" or "fine woven" cloth covers would block the fibers from exiting the items stated above?

Just curious as to this because over time, many of us will be spending large amounts of time in rooms where this may be a concern.

Uh, the answer is as you described it early in your post. Designed HVAC systems have air supply and return ducts.
This is ignoring how any closed room will feel (and smell) without ventilation.
Andre

Thanks Avare. Maybe I didn't make myself clear.

I understand how having a supply and return can "balance" the pressure so that a room has little or no pressurizatiion. My thoughts were concerning "WHEN" the sucking occurs (no matter the reason), if enough energy(air) is sucked out of a room when a door is opened, for a small room, could this disturb the insulation fibers enough to cause them to move and possibly become airborn in a room? I just need to know if anyone has seen this occur, and especially if it MOVES cloth covers on absorbers traps etc. This would be a tell tell sign that if the cloth moves, the insulation behind it is probably moving too.

If the room in/outs were imbalanced enough to cause a major "whoosh" then it's possible that fibers might be disturbed, although I've not seen it happen; two ways to handle this -

one, balance the air as it should be (necessary anyway, for the health of people AND the HVAC system) -

two, cover your batts with really thin plastic ( like painter's drop cloths) before putting on the cloth - this will brighten the room noticeably (if necessary, turn the treble down on the mix, which will also reduce system noise a bit) and contain any fibers.

HTH... Steve

Thanks Steve...
That should "cover" the problem!