isolation room ventilation

[matt thomas]

how does one go about ventilating an iso room? I mean, for good accoustic insulation you're meant to keep it air tight, so how do you get fresh air in and out with out introducing noise?

thanks
narco

[Tibbon]

Probably about the same way that you have the rest of your studio, but on a different branch, or perhaps a different HVAC system. Remember in a studio you want high volume, low velocity HVAC is separated from the studio in some way so there isn't much/any vibration.

What NC are you trying to attain?

[jayfrigo]

Originally Posted by narco

how does one go about ventilating an iso room? I mean, for good accoustic insulation you're meant to keep it air tight, so how do you get fresh air in and out with out introducing noise?

thanks
narco

It's preferable to give the room it's own AC unit, or at least its own feed. Put a few right angle turns in the duct work, build a labyrinth from duct board, insulate all the ductwork, don't run it next to sound sources or let it touch vibration sources, and properly isolate the AC unit itself on neoprene or springs. To do this you'd want to figure the forcing frequency of the noise source, make sure the natural frequency of the isolator is less than 1/10 the forcing frequency, calculate the proper static deflection, and choose the appropriate isolator. If you really wanted to figure this all out, I can provide the equations. If not, just put it on a neoprene pad far away from the iso room and call it a day. The way you build the ductwork and where you put it is probably the larger issue in your case. And you also want to make sure the duct and vent are large enough, and possibly getting larger as it progressess, for the purpose of slowing down the air flow to prevent swooshing out of the vents. Also, the vents themselves should not be prone to rattling as bass heavy sources in the room will cause noisy rattles.

[matt thomas]

thanks, I'm in a nice mild temperate place and don't really need any temperature control, so I wasn't planning on air conditioning at all, more just some ducting and fans. Very few buildings have air-conditioning here, most people jus open a window..

Really what I was wondering was how to stop sound coming down the ducting, because essentially it'll be going outside and I don't want to hear my neighbours coming through my vents?

I'm guessing I should just use quite a long length with a number of sharp corners? Maybe enclose it in a dense casing of mdf?

narco

[Dave Martin]

Honestly, you should try and find an HVAC contractor in your area who has done this sort of work - it can be done, but I'm not sure that even in a DIY environment that doing your won is the best idea.