Isolation Box design (built in 3D softare)

Posted: Wed May 28, 2008 5:43 pm

I'm about to begin construction on my new home studio, which is basically a 9x14x20 room on the second floor of our home. To warm up for the big project, I sat down and designed an isolation box in 3D to get my feet wet. It's something I'll need in the new studio, and I thought it'd be fun to do it in 3D as opposed to sketching it on paper like I usually do. Here are a few images:

(Sorry, my server's been having problems. If you can't see the images, download them from here instead: http://download.yousendit.com/59993124737A405F)

The idea of course is to keep all the computers/external hard drives quiet, while still keep them well ventilated so they don't overheat. I'll be lining the interior of the isolation box with acoustic foam or fiberglass/rockwool, although it's not shown in the images. The front and back walls will be hinged for easy access, and will have a tight seal when closed/locked.

Let me know if this design works or not. I'm pretty new to this stuff, although I've read 3 really good books on studio construction/acoustic treatment already and keep them nearby for reference (books by Rod Gervais, Jeff Cooper, and Mitch Gallagher).

Posted: Wed May 28, 2008 8:53 pm

Your images do not load for me.
I would like to see your box, can you post links instead of embedding it?

Edit: Is working now.

Posted: Wed May 28, 2008 9:23 pm

The only noise my audio computer makes is fan noise.

And you've got 12 of them???

I thought the point of an isolation box was to eliminate the fan noise in the room.

Posted: Wed May 28, 2008 11:44 pm

My hosting's server's having problems, and they're trying to fix it, so the image will be up eventually. I've uploaded to a temporary place now:
http://download.yousendit.com/59993124737A405F

AwedOne wrote:

The only noise my audio computer makes is fan noise.

And you've got 12 of them???

I thought the point of an isolation box was to eliminate the fan noise in the room.

Well, computer noise also come from noisy hard drives and the chasis itself. I can't do a thing about noisy hard drives (short of replacing them, which will cost quite a bit). I figure if I put them into a box, and use only the most quiet fans I can find on the market, I should be able to tame most of the noise. I'm no expert, that's why I'm here asking for suggestions. Smile

Posted: Thu May 29, 2008 6:23 am

Luna,

Interesting design. I'm looking to design something similar, so I am seeing a couple of things that I am addressing myself.

I would reverse the front and back, so that the air intake is towards you and the exhaust is towards the rear.

Follow my thinking...

The heat exhaust should be fairly benign, but it will be picking up thermal rise from the hardware. Rather than have that warm air hitting you, I would port it out the back.

Additionally, any fan noise/air turbulence (and there likely will be at least some) will be louder, the closer it is to your ear.

I would also suggest looking into some type of foot design to raise the box up off the floor by a couple of cm. That will do a couple of things;
First, it will minimize the dust bunny's that you will have collecting in the intake.
Next, if you design it with either a spring based or EDPM based foot, it will help with decoupling the box from the room.

I would encourage you to use some sort of glass or lexan for the front door. If nothing else, to see any fire or smoke inside, but also to watch the blinking lights. Better to just glance at a drive or computer to check on it, than having to stop and open the door just to find out a computer is busy processing.

It would be a lot more work, but it might be worth it to make the front either hinge from the side, or make two doors that hinge from the sides... if you do use glass or lexan, there would be less chance of breaking or scratching the glass.

As far as the number of fans and their placement... You might have a few too many. I'll hope that someone who understands thermal dynamics and air flow better than I do will correct me if I'm wrong...

The way I understand you create air flow is that you either create a positive pressure by pushing air in, or by creating negative pressure by pulling air out.

To create a constant flow with both forced intake and exhaust, you need that pressure to be a 1:1 ratio. The extra fans on the inside have to be placed exactly in the right spot and the air space has to be exactly the correct size and shape so as not to create turbulence that ends up fighting the fans at the intake and exhaust.

What I would do is eliminate the fans at the front and back and ONLY place them in the internal position. That moves the fan noise further away from the openings and closer to the equipment you are cooling.

Again, I may be giving you some poor advice because my knowledge of air dynamics is VERY limited, but that's the way I interpret your design... (and ultimately my own.)

Hopefully someone with greater knowledge will help us out here.

Max

Posted: Thu May 29, 2008 7:15 am

Excellent design!
Far more elegant than mine, which is on casters so I can move easily and monitor sits on top.
The folded path is an excellent idea! Same process as used to isolate HVAC ducts in studios.
Draw (cool) air in from top to avoid dust, side to avoid direct sound transmission. I expect sound escape will be equal at input and output. Vent out bottom back.
You have 3 input fans with space between. Block the free space, it reduces efficiency
The fan(s) can(should) be in a tunnel sized to fit the fan so ALL air must go through fan - this will greatly increase efficiency. Aircraft use this - it's called a ducted fan.
I would put 1 fan in the exhaust duct as far from exit as possible. If that's not adequate add 1 to the input. Fans are "measured" by "cubic feet per minute" of air flow. If you could exchange the internal volume every minute you should have plenty on ventilation. The problem with modern processors heating up is because they are in such concentrated(small) areas.
I have a dual-core AMD in a 2' cude with exhaust of approximatley 20" sq. But the ducted fan will be more effective.
BTW I'm totally unquailified to make these statements - I am not a doctor. But I do play one at home...

Posted: Fri May 30, 2008 4:01 am

Thanks so much for the suggestions!

Before I go ahead and make changes, let me see if I can summarize all your concerns:

1) Don't use so many fans. Keep it to just the interior fans and take out the other ones.

2) Build tunnels for the fans and block off all other space for more efficient circulation.

3) Move the intake to the top.

4) Use glass in the front so I can see the blinking lights/check for problems visually.

5) Hinged from the side for easier access.

As far as which way the exhaust or intake is pointing, I actually plan on having the exhaust pointing away from me (Isolation box will be placed under the desk, with the cables and cords pointed away from me so the cables/cords will be long enough to connect to all equipment on the desk without having to use any extensions).

I would probably place casters underneath the box so I can roll it around instead of carrying it, since it'll be pretty heavy.

I was thinking of maybe instead of having 3 fans for intake and 3 for the exhaust, I should just use one each (largest size I can find--120mm)? Would that not be enough to create air circulation for 3~4 computers plus external hard drives?

Posted: Fri May 30, 2008 5:10 am

Lemme see if I can say this clearer...

I apologize for the hack job... TurboCAD is on another box and all I have on this one is Photoshop.

You could either add a turn at the bottom or just leave it the same and let the intake and exhaust be on the rear. I would suggest the extra turn to eliminate cables from hanging down in front of the intake.

One fan will not do the job. Mount 4-6 fans on a removable plate at each location. Again, ALL of the air needs to pass through the fans.

In the "tunnels" at the intake and exhaust, I would line them with HVAC duct liner to reduce air and fan noise.

I would only window and side hinge the front. I like the idea of the bottom hinge in the rear.

I hope this helps clear up my points anyway.

Posted: Fri May 30, 2008 5:58 am

I would just repeat what I have mentioned a few times in this forum: place the computer, HDD etc. in the next room or hallway (behind the wall) drill the hole for all connection cables, then fill and caulk the rest. Done. Cheap, easy, cool, fast and soundproof.

Posted: Fri May 30, 2008 6:55 am

Cubic feet/minute - that's all you need to know. Move all the air in the box out - once every minute...

Posted: Fri May 30, 2008 6:58 am

Groff wrote:

I would just repeat what I have mentioned a few times in this forum: place the computer, HDD etc. in the next room or hallway (behind the wall) drill the hole for all connection cables, then fill and caulk the rest. Done. Cheap, easy, cool, fast and soundproof.

Groff,

Good to see ya here bro!

In principle, I agree. However, in situations like mine (a larger control room) it MUCH cheaper to build a quiet box.

The length of cabling from the computer to the rest of the hardware interface is longer than the maximum allowable by over 10 feet.

Obviously mine's the exception and if I could place it all in the server room, I would. I have to assume that's Luna's situation, or he only has one room.

BTW, how's the studio sounding?

Posted: Fri May 30, 2008 10:17 am

I might be able to put them into a closet near the desk, but I think the distance might go over 20ft. Many of the stuff I need to connect to the computers are USB audio gear, and I think they do sell products that extend the USB cable length without weakening the signal strenghth. I guess video, mouse, keyboard...etc all can be extended or use wireless.

Anyone can tell me a bit about their personal experience with keeping the computers in another space and running extension cables for all necessary connections? Any problems with signals weakening?

Posted: Fri May 30, 2008 11:07 am

Hello Max, good to see you too my friend…

Well, this was just my suggestion. I don't know anything about Lun's place layout and possibilities, but in many cases like this, inside the apartments or houses it could be done with a little bit of rearranging and changing orientation inside the control room, so the length of connections shouldn't be a problem. I placed ADDA close to the wall with PC behind, so the FW cable is 2' long. All other balanced connections aren't problematic. The only problem was my 15' DVI cable. After replacing it with the better one, everything works flawlessly.

My live room sounds pretty good now, thanks for asking. A friend of mine made some wide and tall stand with the wheels at the bottom and I put the big thick old persian rug on it – looks freaky but cool and works well as a partition when I need more focus, particularly when tracking vocals.

And I'm still reading your diary.... hell of the job, but the place for the lifetime.

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