Where to position an air cleaner?

[Derek Cohen]

I have just purchased an air cleaner. (https://www.machineryhouse.com.au/W326) This scrubs the air on a timer when the day is done and the dust collector is switched off. Big and powerful 1/5 h.p. motor :) Three speeds,1044 cfm air flow capacity.

I understand that the idea is that the air exhausts from the rear and this creates circulation around the perimeter of the room. I have read suggestions that the cleaner be placed about a third way along the wall. I can do no better than one quarter.

https://i.postimg.cc/zDpWxQN5/1a.jpg

In the other direction ...

https://i.postimg.cc/pXTj4BVj/2a.jpg

Comments and suggestions about positioning the cleaner are greatly welcomed.

Regards from Perth

Derek

[Randy Heinemann]

I would guess that, where it's shown in the pictures would be OK. Mine is mounted toward one end of the shop (closer to the wall than 1/3 of the length of the shop) and it has always worked well. Mine is about 25 years old and did not come with a timer (a feature which was added to almost all cleaners after I bought mine) but I installed a timer switch on the outlet the cleaner is plugged into. I would think that, as long as there is unobstructed air flow around the air cleaner on all sides, it should work fine.

[glenn bradley]

I try to picture the airflow like zero-G water. In your picture I see the flow crashing into the wall and scattering. This is workable but, gets you no continuous flow. This makes the cleaner work hard to suck everything to it; nothing is flowing toward it. Given your restrictions you might find a 45 degree (or other) angle to be able to get a semicircular flow going. Its more about motion than single point suction.

433751

[caption] "This would be so much easier if they would swim toward my mouth!"

[Jim Becker]

I don't believe that there will be any issue with where you've positioned the air cleaner, based both on your intended use and my own experience with mine over the years. Yes, "ideally" there are certain positions that are better from an overall air flow perspective, but many shops just cannot support them. I can't put mine in that ideal place because it would be right where my double doors open outward and hang down too far for how I use that area. So like yours, it's about a quarter way down another wall in a spot that doesn't interfere with how I use my shop. Do consider if the inlet side is positioned such that it's pointing in the direction that most of your fine dust creation occurs if you can. And there's no absolute rule that says it has to be parallel to a wall in that respect, although it's generally easier to hang that way...

[Ron Kanter]

Two major consideration are where dust is most often created and where you are most likely to be standing. Positioning the intake side as close to the dust source(s) will minimize dust being pulled through the shop. Having the exhaust blowing toward where you often stand might not be an issue if you only use it after you exit for the day. I sometime like to use it while in the shop to cut down on ambient dust I am creating.

[Bob Jones 5443]

I hesitated a moment before posting this because of the pile of boxes in the middle of my shop, but oh well, full disclosure.

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I got kind of lucky with the placement of my air filter/cleaner. It's about 40% of the way from the wall it points to, but it benefits greatly from the wall-mounted air conditioner just downstream of it that blows perpendicular to the air cleaner's flow. That propagates the circulation around my shop. The dust tools are arrayed on the third and fourth walls, and –– maybe best of all –– the last thing the circulating air sees before returning to the air cleaner is the Wynn filter on the dust collector.

Purists will note that the fine dust flows from the table saw to me on its way to the intake of the air cleaner. I'm stuck with that, given the way the table saw rolls into place, and the location of the 220V outlet.

Derek, I think your air flow will go close to circular around your shop. The cleaner is close enough to the window/sink/Tormek wall that any blow-by to the right of the outlet will be small compared to the left direction, which has more room to move. You might consider placing a small fan above the clamp rack to guide the air.

I also love the timer feature, but I often don't wait until the session is over for the day. If I smell any dust in the air, the cleaner comes on, and in a few minutes I can tell the dust is largely gone. If I want to make sure, I walk outside for a few minutes and that helps me notice any dust smell more easily when I return to the shop.

What a difference the Wynn and the air cleaner have made to my airways! I used to have only the 30 micron cloth bag on the Delta dust collector. Yuck. I do not miss the many evenings when my upper respiratory system was compromised for hours.

[Bill Dufour]

Remember to consider how you will get to the machine to change the filters. Over a work bench you can climb up on is okay but clear floor for a ladder is better. You can hang a piece of cardboard or plywood to angle the flow if needed.
Bill D

[Bob Jones 5443]

Remember to consider how you will get to the machine to change the filters. Over a work bench you can climb up on is okay but clear floor for a ladder is better. You can hang a piece of cardboard or plywood to angle the flow if needed.
Bill D

Bill, yeah, mine requires me to move boxes and get up on the cabinet. Not the most elegant operation.

[Brian Tymchak]

...I sometime like to use it while in the shop to cut down on ambient dust I am creating.

I usually have the air cleaner on in my shop while I'm using most any power tool. Makes a noticeable difference in the air and also on the amount of settled dust.

[Bill Carey]

............ Do consider if the inlet side is positioned such that it's pointing in the direction that most of your fine dust creation occurs if you can. And there's no absolute rule that says it has to be parallel to a wall in that respect, although it's generally easier to hang that way...

I made this mistake - had the outlet pointed toward the dust producing tools. Turned it 180 degrees and it made a big difference.

[Derek Cohen]

Thanks for all the comments. It seems many use theirs when running table saws, sanders, etc. My thoughts were to run it on a timer after I leave since my assumption was that the purpose of the cleaner was to clean the air left by the dust collector.


This collector has two filters. The first is 5 microns and the second is 1 micron.


Now this does not inspire confidence. The dust that is dangerous is below 1 micron. My dust collector has a pleated filter rated at 1 micron. A HEPA filter is 0.3 microns.


The question I have is whether one can add a HEPA filter to the air cleaner? One issue I recognise is that the finer filtering of a HEPA may reduce the air flow through and out of the air cleaner.


If feasible, where does one site it? Behind the main filters or at the outlet?


Your thoughts?


Regards from Perth


Derek

[Jack Frederick]

While I doubt you will have issues with air circulation, should you choose to improve it you could add some turning vanes. Essentially take a pice of sheet metal, or in your case Derek, the curved wood of your choice and set them vertically in a rack to re-direct the air flow. You would need a metal plenum to carry them on the outlet side. They do work well and smooth air flow quite nicely.

[Andrew Seemann]

It is probably fine there. All the air will eventually get to it, less ideal positions just make it take longer. I would consider putting the outlet side on the long side rather than the short side, though. The output air travels further than the inlet air -it is a fluid dynamics thing- so you will get better circulation.

After the filters load with dust, you will get better filtration and capture more of those smaller particles.

I run my air filters while I have the machines on. They aren't that loud, and you might as well get the dust right a way, before it settles out onto the floor and everything else, waiting to get stirred back up in the air.

A couple years ago, I inherited a second air filter. I didn't think adding another air filter would help, but I mounted it up since I didn't have anything else to do with it, and amazingly enough, now the air gets cleaned twice as fast, go figure:)

[David L Morse]

...This collector has two filters. The first is 5 microns and the second is 1 micron.


Now this does not inspire confidence. The dust that is dangerous is below 1 micron. My dust collector has a pleated filter rated at 1 micron. A HEPA filter is 0.3 microns.


The question I have is whether one can add a HEPA filter to the air cleaner? One issue I recognise is that the finer filtering of a HEPA may reduce the air flow through and out of the air cleaner.

Derek

Ambient air cleaners are recirculating filters, so have more than just one pass to remove dust. IRRC, you're in the medical field so your pharmacological training means you understand exponential decay and half life. Whether ventilating a room with outside air or filtered, recirculated air, the decrease in dust concentration over time is an exponential decay. You can Google "ventilation equation" for more information. If you have a 100% efficient filter it has the same half life as pulling in clean air from outside. Specifically, the half life is 0.69 x (room volume)/(fan CFM). For a less than 100% efficient the half life is 0.69 x (room volume)/(CFM x efficiency). So if at a certain particle size the efficiency is 50% then the half life is doubled.

A filter rating is not a brick wall. The efficiency drops smoothly below the value (whatever it is) at the "rated" particle size. So a "1 micron" filter still filters at 0.3micron but at reduced efficiency.

Filter efficiency determine how long it takes to clean the air, not the level of cleanliness you can ultimately reach.

A HEPA filter will probably not be effective a substitute. As you observed, it will reduce the CFM and thus increase the half life at larger particle sizes. Also, and more importantly, the cleaner won't be HEPA rated and almost certainly leaks enough negate the filter performance. If 2% of the air bypasses the filter then your efficiency can't be higher than 98%

[Derek Cohen]

David, there should be a “like” button. Thanks.

Regards from Perth

Derek

[Bill Dufour]

Those turning vanes to direct airflow can be made of ,fire resistant, fabric that absorbs sound. Or panels of acoustic ceiling.
Bill D.
First best photo below

https://www.acousticalsurfaces.com/echo_eliminator/ee_hangbaf.htm

[Bill Dufour]

I have read to hang it on springs so little vibration is transferred into the building. Not important in a stand alone shop. Important in an attached to the house building. You could get really complex and hang it from some rope on pullies to lower it down for filter changes.
Is there some remote indicator gizmo to know when to change the filters? I suppose the old ribbon in the airflow angle piece would work fine. I know for water flow drawing the arc on the wall behind the nozzle can match flows very well. My dad worked with a guy who invented that flow gauge. The guy did not get his Nobel pride for that, it was for other stuff.
Bill D

[Alan Lightstone]

Derek:

Even though I use a respirator until my Dylos meter reads back to ambient particle level counts, I absolutely turn on my two Jet air cleaners while I am generating dust. And I do have a 5HP Oneida cyclone, and use a Festool HEPA vac for things like sanding, so my dust collection is pretty good.

I would definitely not wait until the end of the day to run it. I do often leave it on the timer to run 2 hours after I leave the shop, if I have been generating dust, but your highest particle counts (that you will be breathing) are during tool use.

Yes the noise level is annoying. And loud - especially when both units are on high. But as soon as the particle count returns to ambient levels, I usually turn the big one off, and lower the fan speed on the smaller one to low, or turn it off. At that point I can take off the respirator, and breathe safely.

Alan

[Matthew Hills]

I'd be tempted to put the air cleaner at an angle (draw an octagon inside your garage, and have it on one of those sides)


Matt

[John Stankus]

Why not turn it on and track the air flow. I know they use smoke sticks to visualize airflow with respirators, you could do something similar moving it around the room to see the air flow. Alternatively, something thin and light on the end of a small stick to see the airflow (like a streamer on a wand, a piece of tinsel or something). I guess I have seen streamers on the grills of fans in stores ...something like that.

John

[Matthew Hills]

Alternatively, something thin and light on the end of a small stick to see the airflow (like a streamer on a wand, a piece of tinsel or something). I guess I have seen streamers on the grills of fans in stores ...something like that.

John
Good suggestion.

[Bill Dufour]

Party fog machines show airflow.
Bill D

[Bruce Wrenn]

On my shop made air cleaner, on outlet end, I use two return air grills, turned on their side to redirect the air.

[Bryce Walter]

From what I've read, the really fine dust (the stuff that's really nasty to our lungs and we're trying to get rid of) acts more like a gas in the way it disperses and diffuses through the room. The takeaway that I had from that is that location wasn't overly important.

[Derek Cohen]

Derek:

Even though I use a respirator until my Dylos meter reads back to ambient particle level counts, I absolutely turn on my two Jet air cleaners while I am generating dust. And I do have a 5HP Oneida cyclone, and use a Festool HEPA vac for things like sanding, so my dust collection is pretty good.

I would definitely not wait until the end of the day to run it. I do often leave it on the timer to run 2 hours after I leave the shop, if I have been generating dust, but your highest particle counts (that you will be breathing) are during tool use.

Yes the noise level is annoying. And loud - especially when both units are on high. But as soon as the particle count returns to ambient levels, I usually turn the big one off, and lower the fan speed on the smaller one to low, or turn it off. At that point I can take off the respirator, and breathe safely.

Alan

Alan, that makes sense but, while the air cleaner is not noisy, it is noisier than I can stand. I am very conscious if it when I use hand tools, which I do much of the time.

Regards from Perth

Derek

[Andrew Seemann]

Alan, that makes sense but, while the air cleaner is not noisy, it is noisier than I can stand. I am very conscious if it when I use hand tools, which I do much of the time.

Regards from Perth

Derek

I run mine when I have the machines on. It isn't much of a noise addition at that point, that whole logarithmic hearing thing. I usually run it for maybe 15-30 minutes after I am done as well, basically until I get sick of the noise. It is annoying, but it is the best time to get the dust. Otherwise you are sitting and breathing in the dust you want to get rid of for the rest of the day, unless you only machine right before you leave the shop.

[Alan Lightstone]

Alan, that makes sense but, while the air cleaner is not noisy, it is noisier than I can stand. I am very conscious if it when I use hand tools, which I do much of the time.

Regards from Perth

Derek

Yeah, I wear good ear protection a lot. And I've lost a lot of hearing, so there's that.

The Jet 2000 is especially noisy at the high setting.

[Alan Lightstone]

I've been meaning to post these pictures.

This week I was refinishing some drawers. I used my Festool Rotex sander (AKA "The Beast"), with a Festool Vac.

I didn't turn on the two Jet dust collectors, until I took the pictures.

This is the particle readings from the dust generated by the sanding:
434326

I then turned on both Jet dust collectors on high, and ran them for 2 hours.

Here's the after picture:
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So, if you didn't have air cleaners, and didn't use a respirator, you can see what you would be breathing.

I'm rather fond of my lungs. I turn on the air cleaners, use a respirator, and a good shop vac on the tool.

BTW, a couple of times when I forgot to turn on the cyclone and used my wide belt sander, the numbers were FAR worse.

It's amazing how much fine particle sawdust some of our tools can generate.

[David L Morse]

I've been meaning to post these pictures.

This week I was refinishing some drawers. I used my Festool Rotex sander (AKA "The Beast"), with a Festool Vac.

I didn't turn on the two Jet dust collectors, until I took the pictures.

This is the particle readings from the dust generated by the sanding:
434326

I then turned on both Jet dust collectors on high, and ran them for 2 hours.

Here's the after picture:
434328

So, if you didn't have air cleaners, and didn't use a respirator, you can see what you would be breathing.

I'm rather fond of my lungs. I turn on the air cleaners, use a respirator, and a good shop vac on the tool.

BTW, a couple of times when I forgot to turn on the cyclone and used my wide belt sander, the numbers were FAR worse.

It's amazing how much fine particle sawdust some of our tools can generate.

I thought you had the DC1700-PM. Do you just estimate the PM2.5 per the Dylos formula?

[Alan Lightstone]

I thought you had the DC1700-PM. Do you just estimate the PM2.5 per the Dylos formula?
I have in the past. Plus I have a separate PM2.5 meter which I really don’t think is very accurate. I just go by the Dylos readings.

I know what ambient is and are use a respirator unless it’s down to ambient.

Doing a quick calculation now, using an online spreadsheet, I think that equals PM 2.5 of 142 which is clearly unhealthy. Of course I could be using the wrong number for that, so YMMV.

In any case, I don’t wanna breathe that stuff

[Stanley Powers]

Nice Porsche Derek. What model?

[Alan Lightstone]

Plus, won't a HEPA filter clog very quickly?

I have had one, and now two air cleaners in my shop for 10 years. I monitor their performance with a Dylos particle meter and only take off my respirator when the particle count reduces to baseline. The two now are in pretty good position to promote circular air flow, but even in my last shop (a two-car garage) with the air cleaner mounted pretty centrally in the room, it was very effective, even on the low setting.

So, Derek, I wouldn't worry too much about the placement. It will work well for you. And I totally agree with Jim Becker's approach.

And I agree that the noise from them is pretty annoying. And wearing earphones while using hand tools would annoy me too. You can turn if on, wait until the air is clear, then turn it off. But you would need a particle meter to know when the safe time to turn it off is.

[Daniel O'Neill]

On my shop made air cleaner, on outlet end, I use two return air grills, turned on their side to redirect the air.

I did this as well and it works great for circulating the air in a square shop. At our last place I had put the air cleaner near the heater so I was circulating heat & clean air. Derek I would say that if you want to add a higher quality filter what I've been told/read is that it would need to be thicker to keep as much air flow as possible. Seems thought that the comments have shown that maybe you don't need a HEPA. I think if you put a air direction baffle on the clean side of the filter you could greatly increase the circular motion of the airflow in the shop. Just a thought.

[Jack Frederick]

Thank you, Stanley for getting to the heart of the matter;) Alan with you instrumentation can you tell how long particles stay airborne before settling out. Occupied and not? I know that each shops footprint in this will differ but have you monitored it at all. I, too, am running my JDS filter box on a timer at days end and run it when the machines are in use. I just picked up one of the little Milwaukee M18 leaf blowers recently and prior to leaving take a stroll around the shop to get the debris up into the air. It is a dandy little machine and does a really good job.

[Alan Lightstone]

I can measure it later today when I’m using the wide belt.

It’s minutes, not hours. And my personal shop rule is that I wear my respirator until the shop air gets to ambient levels.

If I run it continuously without making dust, the particle counts get to clean room levels. Pretty amazing, actually.

[Alan Lightstone]

OK, using the wide belt sander for about 10 minutes. And this is with a 5 HP Oneida cyclone, and 6" ducting.

Particle counts reached 3329/1373. (2.5 micron particles / 0.5 micron particles)

Turned on both Jet air cleaners on high, and 7 minutes later the count was down to 337/101, or cleaner than ambient air here (usually about 500 2.5 micron particles). So the time for two air cleaners is less than 7 minutes, probably more like 5 minutes. When I came back to the shop about an hour later, with them both still running on low, the counts were 14/0, which is ridiculously low.

Basically, it's pretty amazing how fast it cleans the air. A single unit would obviously take longer, but minutes longer, not hours.

[Erich Weidner]

OK, using the wide belt sander for about 10 minutes. And this is with a 5 HP Oneida cyclone, and 6" ducting.

Particle counts reached 3329/1373. (2.5 micron particles / 0.5 micron particles)

Turned on both Jet air cleaners on high, and 7 minutes later the count was down to 337/101, or cleaner than ambient air here (usually about 500 2.5 micron particles). So the time for two air cleaners is less than 7 minutes, probably more like 5 minutes. When I came back to the shop about an hour later, with them both still running on low, the counts were 14/0, which is ridiculously low.

Basically, it's pretty amazing how fast it cleans the air. A single unit would obviously take longer, but minutes longer, not hours.

I hadn't turned my Dylos reader on in a while, but this thread prompted me to pay attention to it these past few days in the shop.

Today I did an hour or two of planing and handsawing. 2.5 particle count never went above 500 (Air cleaner was off). I didn't take notes, but it might not even have passed 400.
Used the tracksaw for a bit and things shot up to 2,000. With the air cleaner running on Low ( it is a Delta 3 speed that looks like every other brand I've seen), within 10 minutes things were down to 900 2.5 particle count.
I forgot to look at the time again, but sometime not probably another 15 min and it was down to 2-300 (2.5 micron).

I only run mine when I'm using loud power tools (basically everything but the lathe), otherwise I like music. If I'm using power tools I have earplugs in anyway, so I'll usually let it run for another 10 min after I finish power tooling. I also let it run 30 min after I'm done for the day (hand tools or otherwise). When I turn on the Dylos the next day 2.5 micron count is usually 200-300. (I"ve seen it in the 170 range as well).

One downside of the air cleaner (aside from being stupid loud) is that it seems to sucks in outside air. (Probably good for air quality, but not so good when I'm in a Texas summer and the garage temp keeps going up).
I'm sure this is the air circulation that it doesn't really do great. Probably if I didn't have the double overhead garage doors (you can see a gap of light all around the gaskets), it wouldn't do this.