Thread: Clearvue CV1800 - to filter or not to filter??

Originally Posted by Sandy Taylor

2 questions....
1. We have a fairly large block, but it is in the suburbs - would the exhaust air be clean enough to not cause issues with neighbours etc

Yes it will be fine.

2. Is there any way to soundproof the in and out vent to maintain a good level of soundproof for the workshop? Im worried about both the exhaust air noise, but also noise from the workshop being able to travel through the ducting to the outside (I think flanking is the acoustic term?)

Use a muffler or a baffle box. Do a search for muffler in the dust forum and you will get some ideas. At it's simplest it is a ~1.8m long x 400 x 400 mm play or MDF box, Line the inside of the box with some sort of acoustic insulation and hold it in place using a 200 mm diameter cylinder of chick wire or similar.

Originally Posted by Sandy Taylor

1. We have a fairly large block, but it is in the suburbs - would the exhaust air be clean enough to not cause issues with neighbours etc

If it is a Bill Pentz design (as I understand the Clearview is) I expect exhausted dust will not be an issue.

See my observations on that here. Also, see my air quality (dust particle) readings earlier in that same thread at post #144. I expect with the Clearview unit you will probably get a more than adequate level of air quality in your workshop without having to vent outside; with the usual caveats on leak tight filter connections and efficient dust ports on your equipment

But, if you do vent directly outside, noise muffling/dampening will definitely need attention.

I am unable to pick up an elevated dB reading above background noise further than 10 paces away from my brick veneer workshop, but my fan unit is housed in a brick lined underground cellar and I exhaust through a filter. It's a constant low frequency noise that is generated by the fan unit and they say that this will travel further (think of whale calls and jets taking off) than high pitched noises that have less energy. However, I expect that the low constant rumble coming from the impeller unit will be less annoying to your neighbours than for example the high pitched whine that comes from using high speed power tools.

I know next to nothing about acoustics, but my inclination would be to get some mass into the design of the external venting muffler to help absorb the low frequency energy.

Another factor to keep in mind is that venting outside will almost immediately bring your inside temperature up or down to the outside temperature. So, here in Adelaide, up as high as the 40s in high summer and down into the noughties on winter mornings. The rate of air exchange will also make any form of heating or cooling useless.

In my next workshop I plan on installing a Clearview and running that first with filters and recycling the air inside the workshop while monitoring that with particle readings. If I find that inadequate I will add the facility to be able to switch to venting outside, in which case I may recycle more in high summer and winter and vent during autumn and spring...

I have a Clearview with a baffle box on the exhaust venting through a large grill out the back of my shed - no filters installed. So far there is no visible dust being exhausted and no residue on the vent grill. As for noise, I have mine installed in a cement sheet lean-to and lined it with acoustic batts, chipboard, then heavy rubber. The main noise seems to be from vibration, other than when standing within 3 meters of the vent. Even then my dB meter only showed ~50dB.
Neighbor over the fence was up for a chat a few days ago and asked me if I actually did anything in my workshop as he never hears me.
I am in there every day I can and his back patio is only around 5 meters away so with your build specs, I don't think you will have any problems.

The dust that will be vented in a CV1800 is mostly fine enough that a little wind will blow it away. A good baffle will help with the noise and a bit of dust will collect at the bottom. I'm in Clovelly Park with a 5hp 3ph dust collector and we can't hear it in the house when the door is shut. Shed has no sound insulation just colorbond. No neighbour complaints but I am not running before 10am or after 4pm typically. I try to be considerate where possible. As it's on a vfd, too, i can limit hz to drop speed which significantly reduces noise when i'm not doing very 'dusty' stuff then crank it for the worst offenders such as drum sander, drop saw, table saw, etc.

Make sure your design will contain any overflow resulting from unexpected overfilling of the waste bin and cyclone body. The CV is quite capable of moving everything through the circuit, especially when the exhaust is wide open.
I have done this in the shop as I have not finalized my placement. You get a bit of advance notice when a light “rain” of shavings starts to fall. If your discharge is outside you will not know, but your neighbours might.
I have a friend who has his shop way out in the woods and he vents to the outside. He often makes utility cabinets for industrial clients. He buys plywood by the lift. The bush behind the shop is quite clean considering the volume, but there is good evidence of the occasional bin overflow.
You could employ a shutoff using a photoelectric device to provide an alarm so you can shut the unit down. Many with inside filters use these to protect the filters - actually to protect yourself from the chore of cleaning the debris from the pleats.

Don

While you do not want to annoy neighbours with noise, you also don't want to put up with excessive noise yourself.
I would be putting the Clearvue outside in a soundproof enclosure which, if it is done well, as advised above, gives you the best of both worlds.

Bauldy

If you are still in the planning/design stage of building, putting in a small room or a bump out to contain the CV (some people also put the air compressor in there too) and the muffler/baffle box is easier than sorting it out after. Then you and the neighbours don't have noise issues. If the build is underway then you'll need to figure out where you can fit it. If you make a baffle box for the make up air, shop noise escaping isn't an issue. Just remember to have 2 to 3 times the air exhaust area coming in as going out. If I could vent outside I would do it in a heartbeat. Too cold here. I have triple pane vinyl windows and they are great at reducing noise. You should consider a few windows for some natural light and if you can't get triple pane a pair of double units would be even better. Downside is that windows add more cost to the house. If the no window plan is to prevent break and enter thieves that's different. Have you got a proposed layout and size of shop in mind? Or is it shared space in the garage? Good luck with the build.

Pete

Pete

Thanks so much for everyones help so far - there is a lot to ponder. I'm at the planning stage, so nothing is set in concrete regarding the build. It seems like exhausting outside is the way to go, and with a decently designed baffle, containing the sound shouldn't be a huge problem. If i were to put the CV and say an air compressor outside the workshop, should i design that into the build ie bump the slab out and brick in the enclosure? Should i brick between the enclosure and the workshop or just use framing and sheeting? Would i access the collection drum through the workshop or have a door in the enclosure opening to outside?

I'll aim to get some plans together and also put in what equipment i have so far - that way people can offer suggestions on how to set the ducting and equipment placement as well!

Thanks for your ongoing help!

Cheers

Sandy

I have had more experience than most regarding Clearvues & noise so the following is my suggestion.

I would separate the enclosure to isolate the noise transmission via the building structure and making sure the exhaust is either pointed down or up, down is preferable. Starting from scratch I would make the room double brick and the exhaust baffle the same exhausting at just above ground level. Not many people get the opportunity to to start from scratch so doing it once and never have to worry about noise is a real bonus. The roof would then be the issue and the weak point but that could be easily overcome for such a small room. You would most probably need a hearing aid to detect it was running. For the size of the building the expense to do it that way might even be cheaper than buying good acoustic material as that stuff is not cheap at all and it would certainly be more simple.

Originally Posted by Chris Parks

I have had more experience than most regarding Clearvues & noise so the following is my suggestion.

I would separate the enclosure to isolate the noise transmission via the building structure and making sure the exhaust is either pointed down or up, down is preferable. Starting from scratch I would make the room double brick and the exhaust baffle the same exhausting at just above ground level. Not many people get the opportunity to to start from scratch so doing it once and never have to worry about noise is a real bonus. The roof would then be the issue and the weak point but that could be easily overcome for such a small room. You would most probably need a hearing aid to detect it was running. For the size of the building the expense to do it that way might even be cheaper than buying good acoustic material as that stuff is not cheap at all and it would certainly be more simple.

Thanks Chris,
That would make sense to isolate the enclosure from the workshop. Would having the same slab be an issue. It is my understanding that concrete does not transfer impact sound all that much, so my thinking is it will be ok? So you would have straight duct from the workshop piercing through the workshop walls with some kind of acoustic mastic to fill the gaps, then that duct would be outside a small distance, then penetrate the double brick of the DC enclosure, again with mastic filling the gaps. Is this what you had in mind?
So then you would have some kind of double door access to the enclosure for emptying the DC bin? ie an inner leaf and outer leaf door with some insulation in between.
I'm figuring then the incoming air vent (baffled) will be in the workshop wall itself, and the exhaust baffle will be in the enclosure. Does the interior of the enclosure need any ventilation for the CV motor?? or do you exhaust into the enclosure itself , and then through the baffle which is not directly attached to the exhaust ducting?? (sorry, i probably didn't explain that too well as in my head i was visualising the exhaust duct connected directly to the baffle which would mean that the interior of the enclosure would not get any air circulation)

I would separate the two slabs but only because I could due to building from scratch. The duct between the two buildings would be isolated from the structure with an absorbing material such as wrapping the duct in the rolls of weather sealing strip you can buy from any hardware store, you get isolation and weather sealing that way. The duct could be as simple as a single vertical wall inside the double brick and exiting at the bottom of the walls via a small opening formed when laying the bricks. The internal wall of the duct could be made of anything but MDF is cheap and sound dead into the bargain. Put the VFD in the enclosure as well and the control panel in the workshop via a cat 5 or 6 cable, this a plug and play solution but in a few months there is a more complete answer coming for DE control so more on that later. I am sure others will have different ideas and it will be your final decision in the end.

I doubt cooling will be a problem but the process of the dust going through the cyclone does in itself raises the temperature in an enclosure. The reason I say that is we guys and girls who do this as a hobby do not run the cyclone for long periods of time and the better control on the horizon will make that style of working even easier. The door is an issue but I am sure that it can be solved possibly with acoustic deadening on the inside of a single door. Building this from scratch is something that is not often done and so presents all sort of opportunities and I reckon as your thinking gels around that the plan will be modified as you get further into it.

Originally Posted by Chris Parks

Put the VFD in the enclosure as well and the control panel in the workshop via a cat 5 or 6 cable.

I wouldn't recommend putting the VFD in the enclosure. Every time you forget to empty the bin this can flood your enclosure and VFD with saw dust . We can talk all about how some users religiously check the bin level before use every time but for mere mortals it gonna happened sooner or later and more than once too. The VFD will be safer inside the workshop.

On the issue of structurally isolating DC enclosure from a workshop structure one needs to bear in mind the following. Leaving machinery aside, with the DC outside a workshop, by far the most dominant noise levels cause by a DC inside a workshop will be be from the air rushing around and into ducting and will dominate any noise transferred to a shed structure via any DC enclosure. The sound of air rushing into machines and ducting can be quite irritating and very little can be done about it short of wearing muffs or earplugs.

Enclosure door wise - it should be possible to do it with just one layer of doorway. The 3 doors on my DC enclosure weight 45kg each. The outside is Colorbond, then 32 mm of melamine and then 90 mm of foam. Tho doors need to be well sealed with closures like toggle or cam action clamps pulling down one soft rubber like seals. The noise easily leaks out of even very small gaps in an enclosure.

Regarding motor cooling, I recently installed temperature gauges on the DC motor and the inside of the enclosure. The biggest temperature difference between the two I have seen so far is ~4ºC after running the DC for about 30 minutes. The biggest temperature difference between the air inside the enclosure and outside air temperature with the DC running is around 2ºC. If the DC is not used, because the enclosure is so well insulated, the air temp inside the enclosure does not fluctuate as much as outside air but that changes rapidly once the DC is fired up. Have yet to run it at the height of summer.