Shop Air Cleaner

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CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Shop Air Cleaner

#1 Post by CoronaOperator »

**I'm not sure what forum this should be in so feel free to move it if necessary**

While building my DR250's I became a little concerned with the air quality in the shop. You could see the fine dust in the air and could feel it in your lungs after a breath or two. I use a respirator during sanding and cuts but I don't wear it when doing other work. Also, dust was settling 35 feet or more from my work area in all directions and vacuuming that space was becoming a pain. I took a break from the DR's to build an air cleaner. Commercial air cleaners are expensive and you need proprietary filters for them so I thought I could do better:

I started out with an inline 10" duct fan. They are available on e-bay for about $110 and the 10" model moves 760 CFM. They are fairly quiet, the 10" is 52 dB's. The 12" would move more air at 1200 CFM but is also louder at 55 db's. They were sold out of 12"ers so I went with the 10" model:
Image

I then went and bought some furnace filters. I went with a 16" x 25" x 1" merv11 fine filter (1 micron), a 16" x 25" x 4" merv8 medium filter (5 micron), and a blue washable pre-filter.

I didn't have too much of a plan, I used the filters as a guide for the box dimensions then I just cut out a bunch of 1" strips to make slots for the filters and cut out a hole for the fan. I placed a center strip to help support the filter. I also made an extra 4" slot for future use. I used about 3/4 of a sheet of 1/2" baltic birch that I had for my DR250's, PL and a brad nailer and it didn't take very long:
Image

Test fitting the fine filter:
Image

... the main 4" thick filter:
Image

Here if you look close at the left you can see how I left the slots open to install the filters:
Image

It isn't in the image but I also rimmed the front with 1" strips and made an access cover to close off the filters entrance. I left a touch of overhang on all the joints so I then used a router with a flush cutting bit to trim any excess off. Then a round over bit with the router, a quick sand with 60 grit on the random orbital, and then 2 coats of duratex:
Image
Image
Image
You can sort of make out the access cover. It is held with 2 screws and rimmed with thin open cell foam. It still needs rubber feet and some hooks to hang it from the ceiling and I may even add some corner protectors.

It took me 2 half days in the shop to make including shopping for the filters and waiting for the duratex to dry. I spent around $200 and I feel it out performs $400 commercial units. How? Well, I don't need expensive proprietary filters. The furnace filters are available anywhere and in any grade (merv rating) you want. The extra 4" slot I made I plan on making a frame lined with expanded metal and window screen and filling the frame up with 20 lbs of activated carbon to use as an organic vapour solvent filter. That will clear the shop of any noxious fumes from paint, bondo, glue, etc. 20 lbs of carbon should be good for at least a year and a half of continuous 24h/day use and commercial shop units don't even have that option. Even the thick "greenhouse" carbon filters used for indoor "farming" are only 2" thick. Also, if 52 dbs get annoying, they also make mufflers for those inline duct fans.

First impressions are that I don't know how I lived without one. The air is very clear. There used to always be a haze directly under these super bright LED aquarium lights I use as overheads over my work surface when cutting and that haze is non-existant now even right after sanding. I almost didn't finish the project as I didn't want to unplug it to round over the corners and sand it without it running. The 760 CFM is plenty for me as you can feel that air moving anywhere in that space and it is a pretty big space. If I drop a pinch of fine dust about 3' in front of it, you can see it getting sucked right in. It is also very quiet, my heat gun is much much louder. It is about as loud as my fan in my computers video card while gaming.

The project turned out better than I had planned, I only wish I did it sooner. The $200 I spent was an investment in my lungs and once that carbon filter is built even solvents won't be a bother indoors.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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Tom Smit
Posts: 7457
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Shop Air Cleaner

#2 Post by Tom Smit »

Very good!


May also add a DIY for a dust collector in front of a shop vac? This was shared a while ago. http://www.jpthien.com/cy.htm
TomS

Grant Bunter
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Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: Shop Air Cleaner

#3 Post by Grant Bunter »

CO,
Awesome job :)

By furnace I take it you mean indoor heating systems and consequently filters for same??
I'd make one in a flash, but we don't have much need for furnaces where I am.
Shame that...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Shop Air Cleaner

#4 Post by CoronaOperator »

Tom Smit wrote:May also add a DIY for a dust collector in front of a shop vac? This was shared a while ago. http://www.jpthien.com/cy.htm
Thanks Tom! I was just looking at buying a cyclone for the shop vac as I have yet to attach any dust collection to the table saw. It just spews out everywhere right now. I think I'll give those plans a shot! :hyper:

Grant Bunter wrote: but we don't have much need for furnaces where I am.
They are all the rage over here. They allow for such novelties as liquid water and pets that move around.
Hmm... I'm sure commercial buildings must have some sort of central air mover, cooling, air exchange systems. They would have standard size filters in varying filter efficiency's.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

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DJPhatman
Posts: 5412
Joined: Mon Aug 14, 2006 5:08 am
Location: Warren, MI
Contact:

Re: Shop Air Cleaner

#5 Post by DJPhatman »

Grant Bunter wrote:They are all the rage over here. They allow for such novelties as liquid water and pets that move around.
Hmm... I'm sure commercial buildings must have some sort of central air mover, cooling, air exchange systems. They would have standard size filters in varying filter efficiency's.
Remember, CO, Grant lives in a region where the yearly temps range from 37* to 7*, on average, instead of 31* to -12* like you get.
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

Grant Bunter
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Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
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Re: Shop Air Cleaner

#6 Post by Grant Bunter »

CoronaOperator wrote: Hmm... I'm sure commercial buildings must have some sort of central air mover, cooling, air exchange systems. They would have standard size filters in varying filter efficiency's.
True, it's a matter of finding supply.

I did however find the duct dans.
On Aussie e-bay.
Under Hydroponics :shock:
DJPhatman wrote: Remember, CO, Grant lives in a region where the yearly temps range from 37* to 7*, on average, instead of 31* to -12* like you get.
+1

Our maximum this year has been 47 C
People who have been here for ages say "it's freezing" at 10 C.
Though I did put a jacket on for a couple of hours 2 days this past winter...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Dale Hammer
Posts: 112
Joined: Wed Apr 04, 2012 1:30 pm
Location: Topeka, Kansas

Re: Shop Air Cleaner

#7 Post by Dale Hammer »

Great idea and very nice implementation.

Thanks for posting.

Dale Hammer

88h88
Posts: 1603
Joined: Mon Jul 04, 2011 10:20 am
Location: Coventry, UK

Re: Shop Air Cleaner

#8 Post by 88h88 »

Grant Bunter wrote:People who have been here for ages say "it's freezing" at 10 C.
Though I did put a jacket on for a couple of hours 2 days this past winter...
One of my friends has lived over there for a couple of years now and I just laugh when he says it's cold at 15 degrees. 15 here is t-shirt and shorts weather. :lol:
4xOT12s, 2xT39s@22", TTLS@18", 2xT60@18"

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Shop Air Cleaner

#9 Post by CoronaOperator »

I took a closer picture of the access door:
Image

... and a video of it running to get you an idea of the sound:
http://vid769.photobucket.com/albums/xx ... 090112.mp4

I'm not sure how we got on weather but it was -16*C last week and our letter carrier was still in shorts. My kid couldn't even be bothered to wear his coat walking home from school. I don't even pull out my "parka" (winter coat) until it gets below -18*C. -35*C is pretty much the lower limit for outdoor hockey as deep breaths colder than that can frost bite your lungs. -40*C is what it takes to keep everyone indoors here as even shallow breaths can start to burn. Luckily -38*C is about the lower limit where I live and we only see that for a few weeks of the year, a little bit East from here and you'll run into Winnipeg where the temps can drop to -38*C, sometimes as low as -45*C and stay there for months at a time :shock: . Every year in Winnipeg a few dozen people (mostly elderly) die from freezing to death getting their mail, from the mailbox attached to the house 2.5 feet from the front door :shock: .
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

User avatar
DJPhatman
Posts: 5412
Joined: Mon Aug 14, 2006 5:08 am
Location: Warren, MI
Contact:

Re: Shop Air Cleaner

#10 Post by DJPhatman »

CoronaOperator wrote:I'm not sure how we got on weather
Because Grant has no idea what a furnace is....
CoronaOperator wrote:but it was -16*C last week and our letter carrier was still in shorts. My kid couldn't even be bothered to wear his coat walking home from school. I don't even pull out my "parka" (winter coat) until it gets below -18*C.
I lived in Michigan in winter of '13-'14 (I will be returning as soon as my house here sells) and I plowed my snow, on an ATV, at -18*C (0*F) wearing a short sleeve t-shirt, cotton shorts, sneakers with ankle socks and a pair of jersey gloves (i can't feel my finger tips due to neuropathy). I was drenched in sweat and my entire body was steaming by the time I was done. Ah, fun times <sighs>

p.s. Great job on the air cleaner, C.O.! I wish I had thought about 1 when I built speakers. 9 years and I'm still paying for all the saw dust I inhaled...
I know money often seals the deal, but seriously, quality is an investment, not an expense... Grant Bunter
Accept the fact that airtight and well-braced are more important than pretty on the inside. Bill Fitzmaurice

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Harley
Posts: 5763
Joined: Mon May 08, 2006 2:45 pm
Location: Christchurch, New Zealand - Authorised BFM Cab Builder

Re: Shop Air Cleaner

#11 Post by Harley »

DJPhatman wrote:
CoronaOperator wrote:I'm not sure how we got on weather
Because Grant has no idea what a furnace is...
Yes he does. He lives in one. It's called 'Summer-time in Australia' :bash:
ImageSemi-retired: Former Australia and New Zealand Authorised BFM cab builder.

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Bill Fitzmaurice
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Joined: Tue May 02, 2006 5:59 pm

Re: Shop Air Cleaner

#12 Post by Bill Fitzmaurice »

Harley wrote:'Summer-time in Australia'
Do they call that the Aborigine's Revenge? Not the same as Montezuma's Revenge, but equally unpleasant.
Do you know why the English colonized Oz and not the Spanish? The English lost the coin toss. :loler:

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Shop Air Cleaner

#13 Post by CoronaOperator »

Here is a picture after a week in the shop:
Image

It is about 3 feet off the ground and about 8 feet away from my table saw. I opened it up and tapped the 4" 5 micron filter on the work surface and about 2-3 cups of very fine dust fell out. The 1 micron filter still looked brand new. So far it has been doing a great job of removing dust from the air.
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

CoronaOperator
Posts: 1648
Joined: Wed Mar 25, 2009 7:07 pm
Location: Medicine Hat, Alberta, Canada

Re: Shop Air Cleaner

#14 Post by CoronaOperator »

Guess what Santa brought me for Christmas?

Coal!! Activated charcoal that is, 55 lbs of it! I couldn't find a deal on anything less so I had to order a supply and it just came in. So my first day in the shop after holidays was to build the charcoal filter to remove any solvents/glue/paint from the air.

I made a 3 sided frame from baltic birch and then cut some slots in it with the table saw for some metal grating material I purchased:
Image

I then cut out the metal grating with an abrasive blade on a circular saw to fit in the slots. The grating provides the strength but the holes are too big so I had to find some mesh to prevent the carbon from falling out. I think I found the right stuff:
Image
See, it says right there "charcoal screen"! Who would of known home depot would have shelves of this stuff made just for this purpose :wink: :wink:

I used spray adhesive to attach it to the grating:
Image

Then I slid it in place in the slots with the screen on the inside and cut one side into 2 pieces to make a filling panel:
Image
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Then hot glued around the edges to keep the screen in place:
Image

Then I filled it up with the activated charcoal. It took a whole 5 gallon bucket of it to fill it, about 18 pounds worth. That stuff is way denser than you would think, the 55 lb box it came in is only 16" square.
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I filled it up with the shop vac and a fine filter going, it is very sooty at first. After it was full I gave it a good shake and it went down about 20% from settling. Took lots to finally fill it. That filter weighs about 22 pounds, more than the entire unit I built above. Carbon can adsorb about 30-50% of its weight in pollutants so it will be really heavy when it is time for replacement.

Then it was time to test it. When in place the air flow of the unit drops at least in half, maybe a bit more. That isn't necessarily a bad thing as I will only be using it when solvents/offensive odors are around. I'll remove it when all I need is dust control. The carbon needs about a 0.1 second contact time with the air to be effective so slowing down the airflow shouldn't hurt. After some research I found out that the carbon particles for good air flow should ideally be around the size of a .177 pellet. The stuff I bought is much smaller than that:
Image

Next time I'll order some bigger pellets but I have 55 lbs of this stuff, enough for 2 more filter changes or I figure about 3 years worth.

Today I tried it out while working with fiberglass resin. The fumes never built up and it kept the air reasonably free from smell (the resin was still curing and outgassing). This is good because my shop is below the bar and any fumes escaping upstairs would be horrible. Outside isn't a go for another 4 months yet. I think it would be a good party air cleaner too :wink: .
Built:
17" width 10" driver Autotuba
2 x 29" width dual Lab12 Tuba60
6 x DR250 2510/asd1001
In progress:
2 x DR250 2510/asd1001
For best results, point the loud end of the array towards the audience

User avatar
Tom Smit
Posts: 7457
Joined: Sat Jan 05, 2008 1:24 pm
Location: Sarnia, Ont. Canada

Re: Shop Air Cleaner

#15 Post by Tom Smit »

Thanks for sharing the DIY charcoal filter build! It will be one of my next projects.
TomS

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