John Sayers' Recording Studio Design Forum Archive

Hi again,

So this is my new silencer design. I've increased the size of the paths for the supply and increased the ducting to 150mm. I'm planning on using metal spigots caulked and screwed to the boxes to attach my insulated flexible ducting between the silencers and to the fan etc.
I plan on using a 4 way ceiling diffuser for supply and probably exhaust too (mainly cosmetic reasons, continuity, and the datasheet says it's fine).

Thanks

It looks awesome now!!!!

Greg

Thanks Greg!

I've ordered the materials to build my ventilation system so I'm happy.

Back to construction!

Dan

Are you using any kind of fan to draw stale air out of the room? That's the dilemma I'm running into.

davepettitt wrote:Are you using any kind of fan to draw stale air out of the room? That's the dilemma I'm running into.

Yes, you use a fan that can provide 6 air changes per hour to provide for comfortable oxygen requirements. So mine needs around 200CFM or 340 m3/h. The fan I've installed is an inline mixed flow fan that has 2 settings with the lower setting only 26db and provides 410 m3/h at free flow so should be fine:
http://www.ductstore.co.uk/acatalog/Sil ... -Fans.html

Dan! More pictures please!!

Greg

Gregwor wrote:Dan! More pictures please!!

Greg

Yup, more pics on the build thread:
http://www.johnlsayers.com/phpBB2/viewt ... 10&t=21269

Waka wrote:Hi again,

So this is my new silencer design. I've increased the size of the paths for the supply and increased the ducting to 150mm. I'm planning on using metal spigots caulked and screwed to the boxes to attach my insulated flexible ducting between the silencers and to the fan etc.

New ventilation design.png

New ventilation design inside.png

New ventilation design below.png

I plan on using a 4 way ceiling diffuser for supply and probably exhaust too (mainly cosmetic reasons, continuity, and the datasheet says it's fine).

Thanks

Dan, what cross section do your silencer boxes have? Will the duct between the two silencers be 150mm?

Dan, what cross section do your silencer boxes have? Will the duct between the two silencers be 150mm?

So the duct cross section is 17671.5mm2 and yes The duct between the silencers is also 150mm diameter.

The cross section inside the silencers is 150mm x 250mm = 37500mm2

I'm currently having to redesign the inner leaf silencer as I have less space between inner and outer leaf then on my sketchup design. It's looking like I will have it between the inner leaf joists instead of on top of them.

I'm going to post a new design for them soon (TM)

Dan

Waka wrote:

davepettitt wrote: Yes, you use a fan that can provide 6 air changes per hour to provide for comfortable oxygen requirements. So mine needs around 200CFM or 340 m3/h. The fan I've installed is an inline mixed flow fan that has 2 settings with the lower setting only 26db and provides 410 m3/h at free flow so should be fine:
http://www.ductstore.co.uk/acatalog/Sil ... -Fans.html

Fire up that fan and let us know if it’s really producing only 26 dB. In my limited experience with “silent” mixed flow inline fans, the quoted specifications are usually miles away from reality. Worth checking before you install.

I purchased the following fan which claims to produce only 33db on high and 26db on low. On both settings the fan is about 30db louder than quoted. https://www.fansonline.com.au/fanco-tt- ... 150mm.html

Fire up that fan and let us know if it’s really producing only 26 dB. In my limited experience with “silent” mixed flow inline fans, the quoted specifications are usually miles away from reality.

Yep. Agreed!

- Stuart -

chrispire wrote:Fire up that fan and let us know if it’s really producing only 26 dB. In my limited experience with “silent” mixed flow inline fans, the quoted specifications are usually miles away from reality. Worth checking before you install.

I purchased the following fan which claims to produce only 33db on high and 26db on low. On both settings the fan is about 30db louder than quoted. https://www.fansonline.com.au/fanco-tt- ... 150mm.html

Ye I did take it with a grain of salt, and the measurement is from 3m, so 1m away is more like 38db. It's actually installed already, but outside of the sealed middle leaf in the ventilated third leaf void, so any noise has to go through the silencers or the leaves before entering the room.

Ok so I think I've got a workable design for my inner leaf silencers now. I definitely don't have enough room to place them on top of the inner ceiling joist, so I've had to make the box breach the leaf itself (I'm going to have to be extremely precise making sure this is sealed properly). I've created a boxed section on top of the silencer to take the air to the other side of the box as the gap isn't big enough for the flex duct to get through. This means the diffusers are central in the ceiling (which I like) and the boxes are quite compact.

I think I've covered most of my bases with the new design, but they're a lot more complex then the outer leaf boxes.

From above:
Inlet images:
Extract images: I need a filter to stop room dust etc getting into my extract silencer/fan so I've added a slight dropped ceiling section with an access hatch on the front to replace the panel filter.
This dropped section consists of additional bass trapping and is located against the rear wall.
All of the brown coloured insulation will be covered by fabric stapled between the joists and the seams covered by wooden strips.

Innovative design! The size of these things make fitting them anywhere so difficult. I'm re-designing mine right now and it's proving to be a nightmare, just like yours

Have you checked the specs on that register grill? Make sure it's quiet enough!

Greg

Gregwor wrote:Innovative design! The size of these things make fitting them anywhere so difficult. I'm re-designing mine right now and it's proving to be a nightmare, just like yours

Have you checked the specs on that register grill? Make sure it's quiet enough!

Greg

They are indeed a pain!

I phoned them before I bought it. It has 50% free area, and is 450mm x 450mm. This allows quite alot more than the flow in the silencers, so it looks good to me. Silencer cross section is 37500mm2 and flow through diffuser is 50625mm2.