Author Topic: how to route exhaust out of double or triple wall box  (Read 5333 times)

pz

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how to route exhaust out of double or triple wall box
« on: May 18, 2008, 03:32:50 PM »
I am trying to quiet a generator and have already replaced standard muddler with a car muffler attached to outside wall of generator shed.  Most of the noise is from the generator itself (closing the shed door helps a lot - but not quite enough).  If I build double or triple box, how much clearance do I need to leave around very hot exhuast pipe?  Can I fill this space with something like fiberglass insulation?  Thanks.

johnbergstromslc

  • Guest
Re: how to route exhaust out of double or triple wall box
« Reply #1 on: May 18, 2008, 09:49:19 PM »
Well, standard building codes require 2 inches between chimneys and combustible materials - that's probably about what you need. 

Unfaced fiberglass won't burn, but I wouldn't use it for this application.  When exposed to high heat the binder that holds the fibers together will melt and the batt will disintegrate.  Check into mineral wool - it might stand up better.

bjnash

  • Guest
Re: how to route exhaust out of double or triple wall box
« Reply #2 on: May 20, 2008, 06:15:20 AM »
Well, standard building codes require 2 inches between chimneys and combustible materials - that's probably about what you need. 

Unfaced fiberglass won't burn, but I wouldn't use it for this application.  When exposed to high heat the binder that holds the fibers together will melt and the batt will disintegrate.  Check into mineral wool - it might stand up better.
I am trying to quiet a generator and have already replaced standard muddler with a car muffler attached to outside wall of generator shed.  Most of the noise is from the generator itself (closing the shed door helps a lot - but not quite enough).  If I build double or triple box, how much clearance do I need to leave around very hot exhaust pipe?  Can I fill this space with something like fiberglass insulation?  Thanks.

Standard building practices don't apply here as this is not a residence, just a box to contain generator noise.  The gap depends on the size of the airflow needed to provide cooling.

As detailed on our site at http://soundproofing.org/infopages/generator.htm, the boxes shown have a separation of one- to- two inches depending on the isze of the box.  Don't use fiberglass as a filler, follow the instructions and use the material that's been proven in this application.  The mat at the top of the prices page on our website is the non-flammable material,a closed cell foam,  a sound blocker and dampener, the thicker the better, depending on what level of soundproofing you wish to achieve.

Do you need to add some soundproofing to the muffler itself?



BJ Nash

pz

  • Guest
Re: how to route exhaust out of double or triple wall box
« Reply #3 on: May 20, 2008, 02:06:09 PM »
Standard building practices don't apply here as this is not a residence, just a box to contain generator noise.  The gap depends on the size of the airflow needed to provide cooling.

As detailed on our site at http://soundproofing.org/infopages/generator.htm, the boxes shown have a separation of one- to- two inches depending on the isze of the box.  Don't use fiberglass as a filler, follow the instructions and use the material that's been proven in this application.  The mat at the top of the prices page on our website is the non-flammable material,a closed cell foam,  a sound blocker and dampener, the thicker the better, depending on what level of soundproofing you wish to achieve.

But the muffler is outside of the boxes.  I was assuming I would need to cut a hole through boxes for exhause pipe leading to muffler.  Are you suggesting that I run a flexible exhaust pipe between the boxes, rather than culling holes in boxes?  Thanks for advice!



BJ Nash

pz

  • Guest
Re: how to route exhaust out of double or triple wall box
« Reply #4 on: May 21, 2008, 10:06:09 PM »
But the muffler is outside of the boxes.  I was assuming I would need to cut a hole through boxes for exhause pipe leading to muffler.  Are you suggesting that I run a flexible exhaust pipe between the boxes, rather than cutting holes in boxes?  Thanks for advice!