Exhausting minute amounts of dust and noise issues.

[David Cramer]

As for dust collection, I have no problem on the minimal heat loss for a hobby shop exhausting a cyclone outside, even for us in the cold states.

But I've heard it said many times how loud the noise is if you exhaust outside.

Why can't you just do the following:

After going straight out the wall and then a 90 degree sweep down with another straight piece towards the ground (a couple feet shy), why can't that all be boxed in?

My goal is to do just that on the side of my shop and finish it with OSB, the same white siding that's already there, and 2" rigid foam on the inside to help reduce sound. The bottom would have a square piece of 3/4" wood with a hole cut out to close up the bottom to stop cold air and birds/rodents. The metal 6" duct pipe would have mesh over it, again for birds/rodents and would just protrude below the 3/4" piece of wood.

Inside of it on the shop side would have a flapper to stay in the closed position unless using it, therefore minimizing heat loss. This would eliminate costly filters that just allow only the smallest stuff to pass through anyways, the bad stuff. The box could even have a few screws allowing it to be opened up if needed.

I've never seen this once, anywhere, and for the record I truly know that I am wrong or missing something as someone would surely be doing it this way. My question is what are the negative things of doing this and wouldn't it reduce the noise rather significantly? It seems cheap to do and again, seems like it would really stop the noise. Why is it a bad idea?


Thanks,


David

[Michael Mahan]

I don't feel it's a bad idea as I plan on doing the same here shortly @ my place .
I'm not putting a flapper close off myself
But plan nearly the same setup to stop the noise the next door house might hear

[David Cramer]

I don't feel it's a bad idea as I plan on doing the same here shortly @ my place .
I'm not putting a flapper close off myself
But plan nearly the same setup to stop the noise the next door house might hear


Wow, thank you Michael as I thought I was going insane:) I can't see how the noise would not be drastically reduce.

David

[Robert Delhommer Sr]

I don't find it noisy to vent outside. :)

[Michael Mahan]

I think the cyclone in it's self is the major noise maker
mine will be enclosed in a cabinet that will use that recycled denim insulation (Bonded Logic ) as a sound barrier
I have a ClearVue Max .
I plan on venting out side BUT will wait till I have the thing up & running ,Then see what outside noise is like before proceeding in a outside noise reduction solution .
I'll tackle the inside noise 1st
I do need to make a out noise reduction cab for a compressor but that will be in back yard wall & the cyclone will be on a side wall of the garage with a house just 18' away .
I have a lot of work ahead of me , I find if one does things one step at a time things go easier in the long run .

[David Cramer]

I don't find it noisy to vent outside. :)


Wow, this is truly surprising Robert as I've read it many, many times.

I've actually heard it likened to an airplane propeller sound, which would annoy your neighbors to no end, rightly so.

David

[david brum]

David, I've been venting outside for several years. I sure don't miss cleaning filters or worrying about fine dust getting everywhere. My system isn't a cyclone, so I have it exhausting into a big box with a screen door mesh window. All of the big chips and dust that escape the DC end up in the bottom of the box.

It doesn't particularly make a lot of noise. Outside the shop, it sounds kind of like a dryer vent.

[Dennis Nagle]

I vent outside and when I first installed it I was concerned about the noise too. I brought out my push lawn mower and put it next to the outlet then started them both up. The lawn mower drowned out the DC to the point where I just put the lawn mower away and haven't thought about it any more. To me, it just isn't that loud.

[Darren Almeida]

I vent my 2HP cyclone outside and I don't think it is that noisy at all. I built an attached shed off of my woodshop just for the dust collector. The dust collector vents out the wall of the shed. The shed is insulated to cut down the noise of the unit itself. I also put the unit on rubber floor mats (the cheap $10 ones from HF) to cut down on vibrations. The exhaust noise really isn't that loud. No issues at all. RF remote control makes it super easy to use and I'm psyched to never have to clean a filter. Much quieter in my shop, less dust in my shop (no messing with the filter or the barrel in my shop), and more room in my shop. I just have to remember to go out to the shed once in a while to see if the barrel is full.

[Erik Christensen]

I am not understanding how this is not a major heat loss in cold climates - how is 1,000 - 1,500 cubic feet per minute not a huge heat loss? Seems to me it would be like leaving a garage door open in winter - what am I missing?

[Mark Bolton]

I am not understanding how this is not a major heat loss in cold climates - how is 1,000 - 1,500 cubic feet per minute not a huge heat loss? Seems to me it would be like leaving a garage door open in winter - what am I missing?

The general argument is the thermal mass of the building itself and the contents mitigate a bit of what you will feel. But you'r right, you will be dumping massive quantities of heated air to the outside which will have to be reheated. Then the argument becomes heating makeup air is thought to be eaiser.

My logic has always been, a btu thrown out the window is one that needs to be heated. (common physics). So it boils down to are you willing to eat the heat loss to gain the filter hassle. I have been tempted many times myself to dump to the outside.

The issue I have is even though I have a commercial shop and can technically do whatever I want I have residential neighbors. I would rather keep the peace. Unlike a hobby shop, even though my DC may only be as loud as a lawnmower, it runs almost all day. I dont know many neighbors who would have nice things to say about their neighbor running a lawnmower for 8-10 hours a day.

[Jim Andrew]

If you used one of those heaters that heat objects instead of air, might not be such a big deal to exhaust your air in winter. Doesn't seem like a great idea if you use AC in summer though. I like the idea of exhausting outside, would keep your shop much cleaner, and your dc would work a lot better with no filter.

[Mark Bolton]

If you used one of those heaters that heat objects instead of air, might not be such a big deal to exhaust your air in winter. Doesn't seem like a great idea if you use AC in summer though. I like the idea of exhausting outside, would keep your shop much cleaner, and your dc would work a lot better with no filter.

Not to start a physics debate but a BTU lost is a BTU lost period. If it leaves the building, regardless of whether it comes from the air or an object, its a loss. It all boils down to the basic laws of thermodynamics. If we take any amount of heat from a space, regardless of where its from, it has to be replaced.

Of course the buffer (cushion) of the thermal mass of a structure and its contents could make it feel less unpleasant, the heat is still lost.

[Chris Parks]

I think the cyclone in it's self is the major noise maker
mine will be enclosed in a cabinet that will use that recycled denim insulation (Bonded Logic ) as a sound barrier
I have a ClearVue Max .
I plan on venting out side BUT will wait till I have the thing up & running ,Then see what outside noise is like before proceeding in a outside noise reduction solution .
I'll tackle the inside noise 1st
I do need to make a out noise reduction cab for a compressor but that will be in back yard wall & the cyclone will be on a side wall of the garage with a house just 18' away .
I have a lot of work ahead of me , I find if one does things one step at a time things go easier in the long run .

I tried enclosing the cyclone without exhaust an exhaust muffler and it has little effect and none for the neighbours. Yhe noise level at the exhaust of an Clearvue is generally near enough to 92db, damned loud but it is very directional. There has been a lot of work around this issue done in Australia because nearly all cyclones vent to atmosphere, one is here http://mastslav.weebly.com/


I have stood beside the linked installation and it has a sound level of about 72db and a normal conversation can be conducted right next to it. More installations of this nature can be found on the Australian forums in the DE section.

[Michael Mahan]

I tried enclosing the cyclone without exhaust an exhaust muffler and it has little effect and none for the neighbours. Yhe noise level at the exhaust of an Clearvue is generally near enough to 92db, damned loud but it is very directional. There has been a lot of work around this issue done in Australia because nearly all cyclones vent to atmosphere, one is here http://mastslav.weebly.com/


I have stood beside the linked installation and it has a sound level of about 72db and a normal conversation can be conducted right next to it. More installations of this nature can be found on the Australian forums in the DE section.
ThanX Chris
PM sent

[Erik Loza]

I am no authority on dust collection but have spend a lot of time in a shop with a 3.5hp Oneida commercal cyclone and then many a trade show, shouting over a 5hp Oneida all day long, and distinctly feel that the bulk of the noise seems to come from the resonance within the actual steel cyclone chamber and also the ducting on the supply side. At the trade shows, the exhaust vents out right beside us and that is not nearly as overwhelming a sound as the cyclone, itself. Just my unscientific observation.

Erik Loza
Minimax USA

http://i75.photobucket.com/albums/i315/erikloza/Assorted%20MM%20pics/MinimaxAWFS05booth3_zps2ced2cc3.jpg

[Chris Parks]

Eric, I had the exact same impression so my approach was to enclose the cyclone and see whats left after that. I found with an open exhaust that there was very little reduction in noise and others have found the same. The only effective way is to enclose it and then put a muffler on the exhaust. The I had those who told me they did not think it noisy at all!! The first thing I told every client before purchase is they were damned noisy and it was a fair bet they would have to do something about it. BTW never rely on the DB level meter app you can download, they are useless and a long way out from the real thing.

[Rick Potter]

My 3 HP Oneida vents directly outside. As others have said, it sounds like a dryer vent....on steroids. More of a rumble than anything else.

Rick Potter

[Jeff Nicol]

When I built my cyclone with a 2.5hp motor we vented it outside for a while without the muffler and a filter box, it was pretty noisy and it bothered me more than the neighbors as we butt up against a commerical plumbing yard and warehouse and they make more noise than me during the work day. But on weekends and evenings when all the other city sounds are done for the day it will become "NOISE" pollution for the neighbors to the left and right of my house. So I built a muffler for it and that quieted it down by say 40% and with the filter and dust box a bit more noise was subdued. The problem then became that I needed more space for tools and shop space and I enclosed the lean to that the cyclone was under. So my only option was to move the cyclone up into the attic of the shop and left the muffler on it and by having it upstairs in the back corner it is pretty quiet. But the best thing is that I do not lose any heat or AC in the summer because venting it outside caused a negative pressure in the shop and every little air leak would suck in -10 or +95 degree air which really sucked ! No pun intended! I have wood heat but still takes time to make up the heat/cooling loss no matter what the heat or cooling is. The only thing that I need to do is put a felt bag filter on the exhaust to catch the floor fine dust, but my large dust air exchange filter box catches most of that if I run them in tandem. This is also good in the winter as it moves the warm air from upstairs down and around the whole shop.

Not everyone has an upstairs in their shop so my situation may be only optimal for me.

Good luck and keep the neighbors happy,

Jeff

[phil harold]

I am not understanding how this is not a major heat loss in cold climates - how is 1,000 - 1,500 cubic feet per minute not a huge heat loss? Seems to me it would be like leaving a garage door open in winter - what am I missing?
air will travel the least resistant path
the whole shop will not empty out at once only little river of air coming from air leaks in the building or as I have a 4" make up air vent
then the air moves along the floor to the machine where the air is being extracted
so not all the air is removed, just a stream

[Chris Parks]

What you are missing is the building mass. When air in a building is heated or cooled from away from the ambient temperature what happens is firstly the air temp changes quickly and then the building temp begins to change lagging the air temp. If the heating or cooling goes on long enough the building will arrive at the desired temperature and stabilise. This took relative to the air temp change quite a long while and it will take quite a long while for it to move from what it has stabilised at while the air temp is easy and quick to change. If air is extracted after the building has stabilised and the air temp drops say 10 degrees the replacement air will be bought back to the desired temp by the building releasing its stored energy. It is a good idea to have fans to move air around in a temp controlled room especially if the air temp in the room is going to vary as it will create a more even temp by moving air away from hot or cold spots.