Thread: Clearvue Noise Problems - Take 2

Have a look at this thread....Noise Reduction - CV1800

The main noise culprit is the exhaust and the noise is very directional. Having said that you will almost certainly need to enclose the whole cyclone to totally shut it up. I can now run mine at 65hz any time of the day or night. Any questions don't hesitate to ask.

Thanks Chris. Using one of the free iphone app dB meters I get around 93dB standing in front of the clearvue with the plywood door closed and a similar level around 2m from the exhaust (which in itself is around 3m from the clearvue). In the middle of the street adjacent I'm getting around 83bB. I'm confident I can attenuate noise at the exhaust but what really worries me is the wine coming from the clearvue itself. This will improve when the bottom deck encases the unit fully but I expect I'm going to need to line it with something significant. The neighbour on this side is a full pita so I'm going to need to get the noise level significantly lower. Particularly now that I have already sparked their interest and level of sensitivity.

I forget what mine is now but it is under 70db and I always quoted 92@60hz in discussions with customers. The bats came from Acoustica in Annandale, Sydney, I have no doubt that done properly the neighbour won't even notice it when you switch it on. The sound is very directional and I know Domau on here did what I have suggested to others and ran his into a vertical pipe exiting through the roof. I installed one in an industrial estate a few days ago and the next door workshop started complaining as so we wound it back to 50hz to get him used to it, I will ramp it up slowly over a period of time to see what happens. The exhaust just happens to be pointing at the back wall of his workshop which is corrugated iron so he might have a point when he complains about the whine. The noise will be louder if the direction of rotation is wrong as well.

This is my current setup sound level doesn't bother anyone.

file-6.jpg

Thanks jms. A couple of questions:
1. How is the internal area of the exhaust box configured? Are there baffles or just a straight run path for the exhaust with insulation around it.
2. It looks like you’ve used Earthwool or is it some special acoustic insulation?
3. Why was it just the one elbow section of exhaust wrapped in tape? Is this different to the remainder that looks to be run with Ezyduct?

I’ll drop you a PM as there’s a chance I’ll be in Melbourne soon and depending where you are I’d love to take a look should that be possible.

Thanks for for the help.

Originally Posted by jms_8087

This is my current setup sound level doesn't bother anyone.

file-6.jpg

Is this a Clearvue?

Originally Posted by Flindersia

1. How is the internal area of the exhaust box configured? Are there baffles or just a straight run path for the exhaust with insulation around it.

You can use either. Baffles reduce sound more but straight through will give you minimum back pressure and hence max flow.
A common solution is a 400 x 400 mm cross section MDF box ~2m long with a 200 mm diameter chicken wire core and insulation packed between the two.

It looks like you’ve used Earthwool or is it some special acoustic insulation? .

Earthwool comes in several types - if you already have some Earthwool or similar "thermal only" insulation that you can use that. Earthwool or similar with added acoustic insulation properties is better but not by as much as the extra you pay for it and you can compensate for using the thermal only type by using a thicker layer of it.

Here's what I used for my CV Max (and links to where I got it):

• Earthwool R2.5HD 90 x 430mm (for muffler)
• Whites 90cm x 5m x 25mm x 25mm Cage Mesh (for muffler)
• Black PVC ducting 250mm (ducting for exhaust)
• Dektite 150 - 300mm Black Roof Flashing (shed wall exit)

The entire system is enclosed in 15mm ply (timber frame), with a 140L wheelie bin for dust collection. I was planning on using a 240L wheelie bin, but didn't feel there was enough clearance between the cyclone and bin and figured the extra weight would be a problem... long driveway to haul a full bin.

Below are some pics:
Enclosure
DC Enclosure - V1.jpg DC Enclosure - V2.jpg
The enclosure has 2 doors (1 for the wheelie bin and 1 for the CV Max). It is still open at the top, but so far the DC noise is significantly less than my Makita 30L Wet/Dry Vacuum or my Renegade Industrial Pedestal Fan.
***No actual measurements, yet***

Exhaust
DC Exhaust - V1.jpg DC Exhaust - V2.jpg
Changed from using just the PVC ducting as an exhaust to including the muffler, based off the Corrimal Community Men's Shed design. I forgot to take more pics, but the muffler has the Earthwool and mesh packed in. The final outlet, via the shed wall, is 2 x 225mm PVC 45° bends with a Dektite flashing.

Wheelie Bin
Bin with Viewing Window.jpg

Originally Posted by Chris Parks

Is this a Clearvue?

Sure is.


Sent from my iPhone using Tapatalk

Originally Posted by Flindersia

Thanks jms. A couple of questions:
1. How is the internal area of the exhaust box configured? Are there baffles or just a straight run path for the exhaust with insulation around it.
2. It looks like you’ve used Earthwool or is it some special acoustic insulation?
3. Why was it just the one elbow section of exhaust wrapped in tape? Is this different to the remainder that looks to be run with Ezyduct?

I’ll drop you a PM as there’s a chance I’ll be in Melbourne soon and depending where you are I’d love to take a look should that be possible.

Thanks for for the help.

Hey answers below.

1. There are two baffles in the box.
2. I used some earthwool and some pink acoustic batts I had laying around.
3. I found the majority of the noise was in this first section of the exhaust, another thing to note I forgot to mention that under the tape I did a layer of foam then went to town with the tape...

My first Clearview installation looked similar to JMS's. The tower that supported the CV had acoustic batts installed around the impeller then two layers of 16m/m MDF screwed around all sides of the tower leaving most of the cone and bin exposed. I then built a Corrimal muffler which had about 2.5 metres of pvc that ended under an adjacent shed. I was never happy with this setup as it was still too noisy (down from 93dbs to 84dbs) and used to run it at 50 htz.

Two years ago we moved to a new house so had to start from scratch again so I decided to try for a much quieter CV installation. The new shop is in a large brick garage. I decided to build an internal enclosure about 2000x900 using 75x35 studs. This frame was covered with plaster board on the inside then acoustic batts and 16m/m MDF on the outside. After chucking around a few ideas for the exhaust with Chris Parks I added 4 metre of 10" acoustic HVAC attached to a 10" metal pipe that exits through the roof and a china hat on top of the pipe. As an added bonus there is room for a compressor which got rid of that noise.

I am happy to say it was a complete success. I can now run at 60htz with no worry. The noise within the shop is now 72dbs which for someone who is fairly noise sensitive is excellent. The outside noise at the fence line 6 metres from the shop is not much more than the background at about 59dbs.

Thanks for all the help so far. After yesterdays disappointment there was a positive sign today. I mounted a deck in the base of the cabinet to encapsulate the cyclone (see photo). With the door closed the impact was significant with sound dropping to low 80’s 1m in front of the enclosure. I’m yet to seal the door and add acoustic foam inside the enclosure so I’m hopeful there’s another 5dB attenuation there. Wrapping the impeller might give me a couple more dB but I’m thinking I’ll add a sheet of 15mm F/C sheet to the front of the enclosure behind the door. With some lining on the inside I would hope this would provide good attenuation. With some improved attenuation at the cyclone it’s now clear that the greatest contribution to noise is coming from the exhaust. As I walk towards the exhaust the sound level increases around 5dB. I’ve decided to fabricate a muffler box but I’ll need to wait until after Christmas for that. I’m thinking about a 300mm square box around 2m long with rockwool lining. I’ll add perhaps 2 or 3 baffles so the air needs to snake its way down the 2m length. I’ll add a sketch to the post and would welcome any ideas.


4C081530-53B1-46F7-9E13-1AA5265B9A2E.jpg

Something like the sketch attached. May need to make the openings between baffles a little larger than 100x300mm.

7FF72302-1FEA-4F7C-AB01-FAC5C0DB9AE9.jpg

Bob can confirm but I think you should leave the outlet open without the 9" pipe. Same size as the box. The 9" exit will create more back pressure than if left open ended. The end opening doesn't have to point inline with the box unless you have an installation reason. It could open on the side at the end pointing up/down/left/right or even more than one way.

Pete