Garden Drum Room Build

[Ushmurray]

I'm just wondering... are you going to need the extra isolation that the inner room shell will gain you?

Hi Paul,
When the builders finish the exterior build it will be airtight with a sand filled door. I'm going to do some audio tests and readings then to see what needs to be achieved. Then cut vent holes , test again , build and install silencers , test to see what the silencers are achieving and go from there.

My neighbors houses are pretty are approximately 5 meters away and one neighbor has an garden room office adjacent to my build!

Cheers

O

[Ushmurray]

Hi guys,

I've spent the day battling with Sketchup but I think I'm getting there.

The room is 1270 cubic feet.
I'm going to install a ductless mini split system so the ventilation only has to replace stale air with fresh air.
If I only need 30% fresh air , 127 CFM * 30% = 38.1 CFM

In vent:

Based on the Fantech FG4 4" (100mm) fan to achieve 38.1CFM
CSA of fan is 50mm x 50mm x 3.14 = 7,850mm2
CSA of first silencer 100mm x 160mm = 16,000mm2
CSA of second silencer 100mm x 240mm = 24,000mm2
CSA of register into the room 240mm x 240mm = 57,600mm2
4 x baffles per silencer
1" MDF (25mm)
3/4" OSB (20mm)
5mm tecsound (why not)
20mm Duct liner

Out vent:

I might have these silencers backwards.
I have the larger CSA silencer on the inner room and smaller CSA silencer on the outer room. I'm guessing I have this wrong?

Whatcha think?

O

[Gregwor]

All four silencer boxes can be the same size. If you have the money and space, make them all the size of your big one. If money and space is tight, have them all the size of the small one. As long as they are at least twice the CSA of the duct work feeding them, you should be okay.

Your drawings look good!

Greg

[Ushmurray]

Hi guys,

I hope all is well with you.

I've been updating my silencer design as per Greg's advice

All four silencer boxes can be the same size. If you have the money and space, make them all the size of your big one. If money and space is tight, have them all the size of the small one. As long as they are at least twice the CSA of the duct work feeding them, you should be oka

I'll make the four silencers the same size and that makes them way easier to build.
The big silencer was a little too big depth wise so i thought i'd go for an in between size of the previous design.
I thought i'm going to make them bigger i might as well make the fan bigger so it wont have to work so hard or if the system didn't deliver i'd be able to push the fan more. So i basically upped the design from 100mm Fantech G4 to 125mm Fantech Jetflow (HIT-125 2018)
https://fantech.ie/product/jetflow-029- ... -125-2018/

So the new silencer design is

CSA of 125mm fan 62.5 x 62.5 x 3.14 = 12,265mm2
CSA of silencers 125 x 200 = 25,000mm2
CSA of register 200mm x 200mm = 40,000mm2

New Silencer Design.png

Inner Room Register.png

Undershot Register.png

I'm trying to design the best way to build the walls and roof framing, also how to best hang the internal room silencers and roof.
I'm looking at two products below to support the walls, should be straightforward enough.
https://www.mason-uk.co.uk/dnsb-sway-bracewall-tie/
https://www.mason-uk.co.uk/wic-sway-bracewall-tie/

Full Framing With Silencers.png

The internal room silencers will be fitted straight to soffit of exterior roof.

Neoprene isolation hangers need to be made to carry the specific weights so i need to figure out if this is the best way to do it and then calculate the weights. Get the isolation hangers made and fit it.

To me it seems like there are three elements that need to be hung individually

1.Upper roof frame.
Simple enough, calculate the weight, get hangers to carry the weight. Done

Upper Roof Frame.png

2. Internal room silencers.
I was thinking isolation hangers come down to hold steel bars that run underneath and support the silencers from underneath (not drawn yet). In my drawing i have a 5mm gap between the silencers and bulkhead frame. I'd fill this with some isolation strip but the bulkhead frame would not carry any weight of the silencer.

3. Bulkheads.
At the moment there is an air gap of 10mm between the bulkheads and walls framing. The walls do not carry any weight from above.
These seem tricky to me because of their "L" shape , the weight won't be uniform throughout.

Bulkhead Framing.png

This is the plan so far, I'd love to know if I'm on the right track or there's a simpler better way to do it.

Cheers

O

[Gregwor]

It looks awesome! Personally, I'm not super sold on the idea of "floating" the silencer boxes. So that's up to you to decide if it's worth the money and hassle doing so.

Greg

[Ushmurray]

Hi guys,

I hope all is well with you.

I've been busy taking my drawings to the next stage. I kinda realized I needed to get them further along to make the most out of posting here.

It looks awesome! Personally, I'm not super sold on the idea of "floating" the silencer boxes. So that's up to you to decide if it's worth the money and hassle doing so.

Hi Greg,

Thanks man , I'm designing this with the best case scenario in mind, it might be overkill. I'm very close to costing this all up and that might make me have to make some compromises.

Please excuse the Rockwool colours , i've done this for my own quantity estimations.

Full Room.png

Walls.png

Full Roof Assembly.png

I'm planning on using Mason HD-A isolation hangers to hang the roof construction. https://www.mason-uk.co.uk/hd-ceiling-hangers/
So i've left a 50mm gap between the wall and ceiling framing to ensure the walls dont carry any ceiling weight. This gap will be filled with 50mm Knauf rs60.

50mm Gap Between walls and ceiling.png

I've calculated that the weight of the ceiling framing , rs60 , timber, plasterboard and tecsound layers that needs to be hung comes to 887 kg !

I think I'll be able to do that with the Mason hangers. I'm in contact with a guy there who has been very helpful, i have to go back to him now with my weight calculations.

The weight of each silencers comes to a whopping 104 kg each.
The outer room silencers will be fixed to the external wall and roof by metal framing. The metal framing is there to add support from beneath and stop them from sagging over time or breaking the seal with the wall.
The internal room silencers need to be hung via Mason HD-A hangers, there is a 20mm gap below them to the bulkhead ceiling frame and 15mm gap behind it to the bulkhead frame. I know these silencers could be attached to the ceiling frame but I think that would push the weight past the capabilities of the hangers. This way the ceiling frame doesn't carry any silencer weight.

Fortunately my bro can weld the metal frames up for me.

Silencer Boxes And Frames.png

I've got a quote for a Toshiba ductless mini split system

https://pdf.medicalexpo.com/pdf/toshiba ... 74710.html


Questions i have are

1. On the silencer boxes , is there a recommended distance between outer and inner box? At to moment my distance is 500mm.
I was planning on using Sonoflex flexible duct to connect the two silencers. Can anyone recommend a good material?

2. The internal CSA of the silencers are 25,000mm2. The CSA of the 125mm duct connecting the outer and inner silencers is 12,265mm2.
Should that be bigger more like the internal CSA of the silencer 25,000mm2 ?

3. In the drawing have Reducto Clips and furring bars. If i'm hanging the ceiling and walls are fixed via isolation sway braces is the Reducto clip system pointless?

4. Does anyone have any experience with the Toshiba mini split system?

5. I followed advice of 600mm centres for wall stud framing and 400mm centres for roof framing .
This means 550mm space between wall studs and 350mm space between roof studs for RS60
The Knauf rs60 product i'm looking at comes in 600mm wide bats, should i cut them exactly to fit or should i allow an extra 25mm on each edge for tight fit?

6. I have to look into making some absorption clouds that will go up in between the two bulkheads fixed to the roof somehow. Weight could be an issue .
Would isolated cables that come down through the ceiling plasterboard and caulked be a silly idea?

Thanks guys, my brain is melted with all this stuff all i wanna do is make some frickin noise.

O

[Ushmurray]

Hi guys,

I've come up with my first plan for inner and outer room doors.

The concrete blocks used for the external cavity wall are Roadstone 10n blocks. The spec on them says Gross Density/ Net density is 1900kg/m3.
The blocks are 100mm thick so 1900 x .100 = 190kg / m2.
There's two layers of 100mm blocks in the cavity wall construction so 190kg x 2 = 380kg/m2 is the mass for my wall .

Does that all make sense?

If so ideally I want my external door to equal that mass .
I found a great document on gearslutz about building doors, i couldn't put a link to it but if you do a search for "building studio doors" it's the first thing that comes up.

I was following the instruction on sand filled doors. Ideally exterior door would be steel but I don't know how that would be possible for me to do so
I was thinking a wood door sealed and painted with exterior paint.

The space I have for the frame and stop is 200mm deep so the door can only be so deep.
Following the instructions my external door (pics below) end up weighing 259.62 kg, that's 157 kg per m2 which is not even half of the mass of the wall!!
Also a door weighing 259 kg seems insanely heavy to me and hanging it needs to be done correctly.
If i followed the instructions to the letter my door would need to weigh 608kg and I don't think that's realistic for me.

The inner door is the exact same construction but half the depth , it comes in at 152.92 Kg , 92kg/m2. The interior wall constructions comes in at 41.7kg/m2 so this door well out performs the walls . Would i be better off with a FD60 fire door here with some mass added. From research on the internet i approximate FD60 door to be around 28kg/m2.

Just wondering if anyone had any thoughts or suggestions?

Current plan is

5mm rubber or tecsound sy100? sealing both door openings. Is 5mm to thick?

Outer door: 259.62 kg
18mm ply
100mm dry sand
18mm ply
18mm mdf (bank vault seal)
5 or 6 heavy duty ball bearing hinges

Outer door frame
50x200 frame
25 x 50 door stop 1
25 x 32 door stop 2

Inner Door: 152.92 kg
18mm ply
50mm dry sand
18mm ply
18mm mdf (bank vault seal)
4 or 5 heavy duty ball bearing hinges

Inner door frame
50x100 frame
25 x 50 door stop 1
25 x 32 door stop 2

There is a 50mm air between both frames and 150mm air gap between the doors when closed (this should allow enough space for door lock handles).

Doors.png

Outer Door.png

Inner Door.png

Membrane.png

Door Frames.png

External Door Frame and stops construction.png

[Paulus87]

What's most important is that your MSM assembly of your walls and doors match (or slightly more for doors) this can either be achieved by increasing the mass of the doors or increasing the air gap between the doors. Have you used Gregwor's MSM TL calculator to estimate what you can expect to achieve with your wall and door assemblies?

My point is if your doors are thinner than your concrete block walls then the air gap between the inner and outer doors will be greater than the gap between the inner and outer walls, which means your TL may increase despite the lesser mass. You'll have to run it through the calculator to check.

Paul

[Ushmurray]

Have you used Gregwor's MSM TL calculator to estimate what you can expect to achieve with your wall and door assemblies?

Hi Paul,

I did try Gregwor's MSM TL calculator but for some reason it didn't work for me in Office 10.
I can't remember what the issue was as it's been a while but i'll give it another go .

Thanks

O

[Ushmurray]

Hi Paul,

I just had a go at Gregwor's calculator again.

I've got a two leaf system,

Leaf 1:
Knauf Soundshield Plus 15mm
TecSound SY 100
Knauf Soundshield Plus 15mm
ProSound Reducto Clip
100x50 stud filled with Knauf Earthwool RS60

Leaf 2 is cavity wall.
100mm sand and cement block
100mm kingspan insulation
100mm sand and cement block

I could be doing this totally wrong but what confuses me about this is,

I fill in "Leaf 1 Sheathing" horizontally , it doesn't list the products i'm using and it doesn't list any Knauf RS60 or similar product.
The "leaf 2 sheathing" line doesn't have concrete block as an option so i have to leave it blank.
I fill in "Leaf 2 support material" as sand and cement brick 200mm.

My results give me a TL of Leaf 1 based on products i'm not using and no acoustic insulation rs60
I don't get a TL of Leaf 2 because it can't be filled in.

Either i'm doing something wrong or this calculator just wont work for my construction.

Here's my attempt to fill it in

Screen Shot 2020-06-14 at 17.49.15.png

[Paulus87]

Hi Paul,

I just had a go at Gregwor's calculator again.

I've got a two leaf system,

Leaf 1:
Knauf Soundshield Plus 15mm
TecSound SY 100
Knauf Soundshield Plus 15mm
ProSound Reducto Clip
100x50 stud filled with Knauf Earthwool RS60

Leaf 2 is cavity wall.
100mm sand and cement block
100mm kingspan insulation
100mm sand and cement block

I could be doing this totally wrong but what confuses me about this is,

I fill in "Leaf 1 Sheathing" horizontally , it doesn't list the products i'm using and it doesn't list any Knauf RS60 or similar product.
The "leaf 2 sheathing" line doesn't have concrete block as an option so i have to leave it blank.
I fill in "Leaf 2 support material" as sand and cement brick 200mm.

My results give me a TL of Leaf 1 based on products i'm not using and no acoustic insulation rs60
I don't get a TL of Leaf 2 because it can't be filled in.

Either i'm doing something wrong or this calculator just wont work for my construction.

Here's my attempt to fill it in

Screen Shot 2020-06-14 at 17.49.15.png

Looks like you're using a slightly different version to me, I'm using this version:
https://docs.google.com/spreadsheets/d/ ... 1543869474

You need to go to file and make a copy first before you can edit it.

Yes it doesn't have every single product, but all you need to do is choose anything as the product, then select custom, and then put the surface density for each in the box beneath. So, as long as you know the surface density for each layer of your leaves then it doesn't matter what it's called in the product menu.

You do not need to put the insulation in as part of the leaf as it will work out the cavity resonance with and without insulation for you, the type of insulation in the cavity has a negligible effect on TL.

For the concrete block support structure you can choose "PCC Concrete (without steel)" for example, then go to the bottom tabs where it says "data" then find box O, 22 and change the value to the surface density of your concrete blocks (kg/m3) then go back to the TL Calculator tab and to see the results.

The "GAP BETWEEN SUPPORT STRUCTURE MATERIAL" is the gap between your concrete blocks and the studs.

Hope that helps,
Paul

[Ushmurray]

Hi Paul,

That's helped me tremendously , thank you so much.

I've entered the wall info as follows

Leaf 1 :
Knauf Soundshield 15mm @ 12.85kg/m2
Tecsound Sy100 5mm @ 10kg/m2
Knauf Soundshield 15mm @ 12.85kg/m2

Leaf 1 support : 2 x 4 stud
Leaf 2 support : PPC Concrete w/o steel

Gap between support structure : 50mm

See results below

Walls Screen Shot 1.png

Walls Screen Shot 2.png

Walls Screen Shot 3.png

Walls Screen Shot 4.png

For the doors i've entered

Leaf 1 : (outer door, 100mm sand)
Birch ply @ 9k/m2
100mm Dry sand @ 160kg/m2
Birch ply @ 9kg/m2
Mdf @ 11.11kg/m2

Leaf 2 : (Inner door, 50mm sand)
Birch ply @ 9k/m2
50mm Dry sand @ 80kg/m2
Birch ply @ 9kg/m2
Mdf @ 11.11kg/m2

Gap between support structure : 150mm

Doors Screen Shot 1.png

Doors Screen Shot 2.png

Doors Screen Shot 3.png

So if i've done this right it looks pretty good to me.
The doors outperform the walls slightly , i'm quite surprised at that.
I'm getting 70db TL down to about 160hz and falling to about 40db TL at 50hz.

What do you think, is this is a good result?