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R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: DeVille on February 17, 2007, 04:11:12 pm

Title: A/C Isolation
Post by: DeVille on February 17, 2007, 04:11:12 pm
Is it possible to isolate A/C noise in a high wall mini-split type air-conditioner in a recording area by enclosing the unit in fiberglass duct board and possibly other materials in an effort to make the recording area quiet enough to leave it on doing recording?

These units generate fan noise typically from 28db to 42db depending on model and fan speed.

Title: Re: A/C Isolation
Post by: franman on February 18, 2007, 12:49:48 pm
These units need to be open to the room to work. The air must be free to return to the unit. You have to be careful if you create an enclosure, to not restrict the air flow in and out too much, or else you'll have a quieter room with a very cold box hanging on the wall.

We don't generally use these ductless units in a recording room. Even the quiet ones are just too noisy in any circumstances to have on during recording. They are a good solution for machine rooms (or closets) and a last ditch solution for control rooms if nothing else will work, but I'm not very optimistic about trying to create a duct board enclosure.

I'm sure you could quiet it down by 6dB at least, but I just don't know if the unit will still cool the room. Let us know if you move ahead, how things work out. I'd be curious to know what you build and how it worked.....
Title: Re: A/C Isolation
Post by: DeVille on February 19, 2007, 06:29:17 pm
You're right I'm not optimistic about it either. I was going to throw just about every noise reduction technique for duct fabrication at it. But with the noise source directly in the room. I know it will be very difficult.

I opted for a one room setup here at home because I am not allowed to do any major modifications to this residence. However, turning the A/C on and off during vocal tracking sessions is tough. It causes a lots of fluctuations in pitch especially in horns. Not good for my equipment either.

I got a few projects to complete while I'm looking for a new location. I'll let you know how it goes.

Title: Re: A/C Isolation
Post by: jimmyjazz on February 20, 2007, 12:33:56 am
I used them in my last place, simply because they maximize interroom isolation and most of my recording (at the time) was pretty loud rock'n'roll.  And, in that context, they weren't a big problem, at least while tracking a band, or loud guitars, etc.  However, they were too obvious while tracking vocals, and presented a bit of a hassle.  Fortunately, the studio was extremely well insulated, so it was possible to get the room to a comfortable temperature before a vocal session and get away with no HVAC function for as much as two hours.  It also made for a nice excuse for a break.

Not the answer you're looking for, I realize, but Fran already covered that.