Ventilation for small control room.

roguesounds

New member
Hi guys,

I'm in the process of converting our garage into a small control/overdub room mainly for tracking guitars/acoustic instruments. We've completed beef up of the external walls (2 layers of 16mm fyrcheck between studs and rafters all caulked up) and am starting to put internal walls/ceilings on. Am looking into getting fresh air into the room mainly for at night when the doors would be shut for longer periods, but am also concerned about penetrating my newly beefed up walls. I was thinking of mounting an inline fan in the roof space between my inner and outer leaves with a baffle box at either end of the in and out ducts. ie vent on exterior of garage going through outer wall into a baffle box, then air duct into the fan intake, then air duct from fan output to another baffle box mounted on the rafters, into vent on inner ceiling.

Would this maintain my isolation to the outside world?

Thanks for any advice.

Jochen.
 
Are you just looking for basic air flow...or do you need cooling for the hot months and heating for the cold?

People usually underestimate the temperature requirements, and in most recording studios, cooling is needed...though in the dead of winter, some heating too, unless you have a decent amount of audio gear that is always left powered up, in which case it will generate a good deal of heat for you.

AFA how to punch a hole for airflow, while maintaining soundproofing...that's a rather involved subject and solution...but I'm sure you can do something that will be good enough. I mean...do you need it to be 100% soundproof no matter what?
Any kind of vent will allow sound to move though it, so I think it would need to be lined with absorptive material, and include a few "kinks" rather then run as a straight-line vent.

I'm not able to visualize your build to give you any specific suggestions.
In my studio space...I have windows that I can open for basic outside air, which I'll do on occasion, but other than that, I ran a single AC duck into the space, and it's a long, insulated vent that runs all the way up to the roof, where the AC fan unit sits....and the vent is all boxed in, and wrapped with more insulation where it is on the outside of the building for a short piece.
That pretty much cools my space and circulates the air, since I generally keep the inside studio door open to the rest of the build...so the air circulates.

I'm not understanding why you specifically talk about need to vent the space at night...?
Just shut the doors and leave it be...what's the problem with doing that?
 
Aircon is great, but recirculating air on it's own in a small room can be quite horrid. The secret to getting new air in quietly with isolation is the diameter of the ducts. 4" ducting and axial fans are too noisy. 8" works pretty well as the speed of the air is lower. The in-line silencers are pretty decent, but expensive. Rock wool lines MDF works pretty well with a labyrinth path. My last build had the inner skin 'holes' and the outer skin 'holes' separated by 6mm and silicone in the gap. It still gives me sufficient fresh air and sound isolation. Mine sucks out from the roof, and injects fresh lower down.
 
Are you just looking for basic air flow...or do you need cooling for the hot months and heating for the cold?

Just basic air flow for when the door is shut. I can turn vent off when tracking. It's mainly just to circulate air.


AFA how to punch a hole for airflow, while maintaining soundproofing...that's a rather involved subject and solution...but I'm sure you can do something that will be good enough. I mean...do you need it to be 100% soundproof no matter what?

No, doesn't need to be. The sound proofing is more to keep everyday noise (eg mowers, kids in yard etc.) out when tracking and to keep noise (mix volumes, acoustic instruments etc.) escaping to a minimum if i choose to work at night.


I'm not able to visualize your build to give you any specific suggestions.

I'll get a diagram and a few pics up when i get 5!


In my studio space...I have windows that I can open for basic outside air, which I'll do on occasion, but other than that, I ran a single AC duck into the space

Does the duct penetrate the wall and how did you stop sound escaping through the penetration? That's pretty much what i need advice on. I'm worried I'm going to ruin any isolation I have gained out through the air vent path...


I'm not understanding why you specifically talk about need to vent the space at night...?

Sorry, what i meant was when i'm working in the studio at night (tracking, mixing, rehearsing) and have the doors shut for longer periods.
 
My last build had the inner skin 'holes' and the outer skin 'holes' separated by 6mm and silicone in the gap. It still gives me sufficient fresh air and sound isolation.

Did you have any "baffle boxes either side of the "holes"? Also did you use fans to drive the air?
 
How did you get pipes through the walls without disturbing the sound proofing. Would you create a flanking path via the gas and drain pipes?

The interior unit covers the hole in the wall. The hard part was cutting a hole through the exterior brick veneer. :( That part I sealed up to prevent weather and bugs from getting in. It would work to provide sound isolation as well.

Also, it should be noted, I did not put much effort into sound isolation. It's only me and I don't get very loud. My little studio/office is half of the third car garage and isn't really attached to the house, so it doesn't transmit sound to the house.
 
Does the duct penetrate the wall and how did you stop sound escaping through the penetration? That's pretty much what i need advice on. I'm worried I'm going to ruin any isolation I have gained out through the air vent path...

Yes...the duck penetrates the wall to the outside...then it goes through another wall, into and through another room in order to get up into the attic and to the evaporator/fan unit.
I then insulated and boxed off the vent both where it goes outside, and also where it was inside the other room...so it's no different than having the duct walled off and inside...and the duct(s) all end up in the attic where the main unit sits, while the big compressor unit is outside. The sound never goes "outside" (or come inside) because of the vent.

You're just talking about an air vent to the outside...mine is a duct to an AC unit.
 
Re: my air circulation system - the foul air was sucked out with an 8" duct fan and the inlet for fresh air from outside was just pressure differential fed. The fresh air travelled down through an MDF duct lined with 1" foam. No baffles , simply openings and they were inaudible in operation at half speed on the fan. Full speed on the fan was just noticeable.
 
very good question. do your research and use what's in your budget. Mitsubishi makes an interesting room cooler that vents directly outside. I guess you know any cooling/vent system would be turned off when tracking.
 
very good question. do your research and use what's in your budget. Mitsubishi makes an interesting room cooler that vents directly outside. I guess you know any cooling/vent system would be turned off when tracking.

Yep, definitely turned off when tracking! I have a portable air con that i can sit in the corner of the room but once again, it would need to vent it's hot air outake outside through both my leaves. This would probably cause flanking and ruin any isolation i have achieved.
 
Hey guys,

thanks everyone for your input. Just to clarify, I'm not so worried about fan/air noise from the vent as much as I am more concerned about sound leaking in and out of the ducts thus ruining any isolation I achieve with my two leaf system.

I've been researching this for a while and always seem to come across conflicting info. I have come to the conclusion I willed to use a baffle and I understand the theory behind it, but confused about where it needs to sit and what to run in and out of it to maintain isolation in my room.
 
I use a Mitsubishi split system air con that is so quiet that on low fan it can be left on, try 21 dBA. I close the door when tracking, when mixing or tinkering around leave the door or window open a bit. Much cheaper solution to fully ducting the studio.

My last studio had a fully ducted air con, I build extensive Large baffles before the room outlets and run the ducting from both rooms back to the air con unit not between rooms. The duct run was over 10 Mtrs (approx 30 Ft) this is not practicable for a home studio but this is what you are up against to isolate sound from air con ducts. My current building would have been a nightmare to duct so I went split, works fine.

Here are some other ideas Link page 33.

Alan.
 
Yep, definitely turned off when tracking! I have a portable air con that i can sit in the corner of the room but once again, it would need to vent it's hot air outake outside through both my leaves. This would probably cause flanking and ruin any isolation i have achieved.

If that is like the one we had at work some years ago it has a long, flexible hose, about 4" OD? So, have a fitting on the wall with a lined duct to the OSWorld and "plug" the AC hose into that. Run the ***t off the AC unit to chill the Marjies, then unplug the hose and stuff in a semi-rigid foam plug with a dense end plate. That should stop sound ingress and exit for a tiny bit of extra time and work.

Dave.
 
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