Make less noise (ventilation)

[CalMag]

Hi guys!

Today i've tryied to put a blauberg 150mm centrifugal inside a paper box and putting some rockwool, paper and clothes around the vent and then i closed the box but it was noisy, just a lil bit less than without the paper box..

I hear a lot of Air movements and probably If i buy some rockwool sheets i can put it around the 150mm tubes(or just buy a soundabsorber tube) but..

Tomorrow i want to finish the work and buy everything that i need to do a better job.

For the "box", should i use mdf or other woods material or plastic or xps/eps or metal?

I think that the heavyer material will work better for "isolation", but i can't find any Lead(Pb) sheets in the local shops.. maybe in a car sound tuning shop..

So wood or metal should be greater than just a hard paperbox..

So inside i need something that can absorb the sound, and i can surelly use some mineral wool(very easy to find here) or foam.. i will probably like more the foam If it is more efficient.

I have seen what others people have done here on Ic and Someone use Musicstudio absorbing materials, mdf/wood outside, Someone else just hardpaper and clothes..

So.. could i get some better/less noise by using a wood case and foam that expand with capacity to absorb the sound?

This stuff just for the motor noise..

I don't know If it's Ok to let the vent stay inside the foam or If it will burn up..

Then..

For the air movements noise.. just soundabsorbing tubes are ok?

Because with the bigger one Blauberg 200Max i can hear air noise too and there i use soundabsorbing tubes.. less air noise, but a good part of noise..

Maybe longer tubes will absorb more sound.. If anyone have experience maybe can answear me..

.. Someone make a box with fake walls inside made with soundabsorbing pads at the end of the tubes..


I grow in a place where i don't want to make too much noise.. i can't afford more quiet vents now so i need to "tune" instead of "change"..

If i gave too little informations, i can tell more or explain better.. sorry for My bad english!!

CalMag

 

[OldPhart]

I just used a 25' insulated flexible duct between the fan and the vent/filter. It is amazing how much sound is trapped/adsorbed with the long flex ducts. https://www.lowes.com/pd/IMPERIAL-6-in-x-25-ft-Insulated-Polyester-Flexible-Duct/50401792 I personally like the Poly over the silver coating on the outside, because it seems to be more durable. Not saying this is the cleanest, or smallest solution around, and you do need to have the ducts fully extended. You don't have to stretch them, or have them straight, just not wadded up. I would mount the fan in the middle of the wall, then run one tube around the ceiling to the filter, then run the other tube around the floor to the vent. Just some ideas.

 

[CalMag]

Ok, the duct that you have posted in the link seems to be better than My ducts..

My ducts are in aluminum, like the the alu paper that we use in the kitchen for food..

I have a bigger duct that have: aluminum --> transparent plastic over the duct --> rockwool --> plastic that holds everything tight

The one in your link have some pink stuff and not Yellow like the big duct that i own.. maybe the pink material could be better?

With vent i mean fan, i wrote it wrong.. will those ducts Reduce some of the fan noise too?

Thanks oldphart!



Edit: just for tell more info, i have a 240x120(9ft x 5ft [if i'm not wrong]) and a 60x60(2ft x 2ft) for clones and moms..

The room with the growboxes inside is 11x12ft

1 blauberg 200Max centrifugal (from the inside of the big box to the filter)

1 blauberg 150 centrifugal (cooling My reflectors)
1 blauberg 150 centrifugal (intake)

 

[OldPhart]

You have a lot more fans than I have ever ran, all that I was trying to say was putting a full 25' of insulated duct on both sides of the fan took care of all my noise issues; I didn't even bother with insulating the fan its self, because it wasn't making much noise. As far as the color of the insulation, I doubt that would matter any. It's one thing to find a home for 50' of duct in a room, with three fans, I can't imagine 150' of ducting in one room; so I don't know that this would be a reasonable solution for you.

 

[CalMag]

Well, actually i think that your way could be used also in the room where i grow..

To make it easier i could just use 2 fan (1 exhaust+lightscooling, 1 immission) but If i use 10' for both sides, the efficiency of the fans will lower a bit.. but.. better less noisy than 100m3h more power in my case.. so i will buy some ducts and hear the difference(i needed those ducts anyway)

Thanks OldPhart!

Edit 16.00: now i have tryied to put some mineral wool for isolation around a 40cm duct that stick out from the paper box, and it works much better, but not perfect because the duct is too short so the air is pushed out against the Roof and this is not good, i'm trying to avoid the noise to go upstair..

So i will buy some scrumble mineral wool to push in the paper box instead of clothes and paper sheets so i will lower the sound og the motor much better without the needs to use wood(hard paper like packaging paper is much less time to work with[and less noise from machines for cutting holes..])

Then, i will use a 1 meter/4ft duct not sound isolated(the one that i have for the 150mm) and buy a big roll of mineral wool 10cm thick and roll it around the duct starting by the inside part of paper box where the duct start.. then i can probably just use a tape to hold the Yellow mineral wool togheter and put on the outside some windblocker sheet roller around a tape it for good strongly..

Then i will do the same thing with the duct INside the growbox..

If it works, .... i need to make it works.

I will update tonight so anybody that come here can see If it works this way or not.. i will find some long ducts and try with the big fan what OldPhart told me, i think it will actually work.

 

[CalMag]

So, i did it.

I used a double Wales hard packaging paper, rockwool to separate the fan from the paper, a mineral wool bed between rockwool and fan and 18m of mineral wool pressed in the box and stripes rolled around the fan. So more stripes on the fan before closing everything with very resistent tape (thick too).

I used also 50mm mineral wool and thick flexible plastic to make those sound absorbing ducts and it works soo good!

I just need to fix the duct inside the box tomorrow.

So.. 1 of 3 is done!

The mineral wool+plastic costed me 40€/$ for 3 meters / 10ft.. more expensive than from hydrostore, but it works better than the 200mm sound isolated from the hydrostore too.

Thanks to everyone!

Edit: the last part of duct, is not the original duct, this is just a 200mm duct piece that i will remove tomorrow.