Author Topic: deadvent and triple leaf effect  (Read 2755 times)


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deadvent and triple leaf effect
« on: July 01, 2015, 06:46:50 AM »
 Dead vent : is it size or volume that matters?

Building a drumming room, 10'x6' division of a basement. To ventilate I was going to use dead vents, though am only using 4" flexduct as flow requirements are low and ventilation noise is not a problem (you won't hear it for the drumming). Now outside the room there is only 4' spare and specs state 2'x'2 box. Giving volume of about 2x2x6 (low ceiling) of 24 cube Ft.

Q1. given the smaller duct size, would a 1'x4'x6' box be as effective(same volume).

Two of these would effectively be the width of the double stud wall I'm installing, so...

Q2. Would this induce triple leaf effect.

plan would be DD GG, 2x4, 1"gap, 2x4, single drywall, deadvent, DD GG. I would mount fan externally for easy access and because it will only be running when I am drumming.

Q3. Budget is tight (as usual) so given diminishing returns, would my assumption that GG 1 tube/board on both int/ext faces would be more effective than GG 2 tubes/board on just interior.

any advice welcome

Randy S

  • Guest
Re: deadvent and triple leaf effect
« Reply #1 on: July 02, 2015, 03:34:14 PM »
Normally I use baffle boxes for my projects not dead vents which volume and size matters based on the CFM requirements needed for the room size and the value of reduction needed. Your room is small so it should not be an issue any way.
Q1. same volume you should be fine.
Q2. as long as you insulate around the flex duct and fill each box this shouldn't be an issue like you would get with hollow boxes.
Q3. I would do 2 tubes of green glue on the source side for sure and then continue as planned, remember that a 2 tube formula is 70% greater performance above a single tube per sheet.

Always remember that when designing these soundproof rooms it really all comes down to how loud you want to be and how quiet it needs to be on the other side, so the amount of DB reduction really dictates how much needs to go into these rooms and with budget constraints you just do the best you can do.

It would be great to hear the results when complete.

Feel free to contact me direct if you have questions or concerns.

Randy S.