My Long Wait for a Workshop #5: Home Made Air Filter

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Blog entry by JWags posted 04-26-2011 05:24 PM 18969 reads 17 times favorited 13 comments Add to Favorites Watch
« Part 4: Slowly But Surely... Part 5 of My Long Wait for a Workshop series no next part

Hello again,

Just finished my homemade shop air filter. I had to change my original plans, which were to hang it from the ceiling. That’s because I also wanted a washable filter, to keep down on the ongoing costs. So here was the final criteria: I needed a blower that would draw and push at least 800 CFm, a primary filter that would catch up to 5 microns, and a secondary filter that would catch 1 micron particles, and not be cost prohibitive. Plus – it had to be quiet.

So – I’m lucky – I’m in the real estate business, and have to regularly deal with HVAC people, plumbers, electricians, etc.

I put the word out to the HVAC people that I was looking for a take out blower and cage – in good working condition – hopefully with several speed selections. Lo an behold – one showed up not 8 days later – from a home that was being remodeled using in-floor radiant heat. Yipee – step one…

The 1 micron washable filter I found at Grizzly ( if you’re interested). I live at almost 9,000 feet – the air is already thin – so I really wanted good filtration. But this filter changed the configuration – it needed 18 inches to work. I wasn’t going to hang a coffin sized box from the ceiling, so I decided to build a roll around filter. Make it 1/4th less tall than my tablesaw, so it could double as an infeed table, and make it sturdy enough to put my future surface planer on. Kill 3 birds….

So I had to horizontally mount the blower. This would require some support for the side opposite the mounting holes.

So dowels with rubber tips seemed like a good candidate.

And I think I found a simple solution to dampen the motor vibration – I mounted it over some rubber hose:

So here is the blower configuration:

Now I needed intake holes:

and here’s a pic of the bottom – it should stay where I put it:

I didn’t want the exhaust too close to the intake, so I side mounted some floor registers. I’m also not glueing the back or top so I have future access to the guts if maintenance is needed.

So here is the semi-final assembly:

and from the back:

And after a coat or 2 of paint (Grizzly colored of course – lol), here it is finished:

It’s very very quiet, and rolls around easy (I put a big handle in back…). I just finished using it as an infeed table for my TS (I’m ripping out the parts to finish Norm’s workshop Hutch…). The primary filter is already showing signs of dust, after only about 15 minutes of operation.

I think my lungs are gonna thank me! And thanks to you for reading!

-- James - I don't like jogging - the ice pops out of my glass...

13 comments so far

View Will Stokes's profile

Will Stokes

267 posts in 4691 days

#1 posted 04-26-2011 05:34 PM

Nicely done! I could use one of these.

View dbhost's profile


5864 posts in 4568 days

#2 posted 04-26-2011 06:08 PM

Very interesting design. Most of them I have seen are straight through pull arrangments, first time I have seen the box stacked like this.

-- Please like and subscribe to my YouTube Channel

View JWags's profile


64 posts in 3997 days

#3 posted 04-26-2011 08:25 PM

Thanks Will -

dbhost – This desgin was an attempt to make the best use of space in my very small shop. If I can make something that has dual or triple use or purpose – all the better. Thanks!

-- James - I don't like jogging - the ice pops out of my glass...

View Grandpa's profile


3264 posts in 4012 days

#4 posted 04-26-2011 11:02 PM

Great job. This looks really good! IS the blower working okay positioned like this? I thought someone was having a problem with noise the other day day and another writer said to turn the blower where the shaft was horizontal. This looks good and if it works that is even better. Thanks for posting. Does it draw in the smell of those pine needles?????

View JWags's profile


64 posts in 3997 days

#5 posted 04-26-2011 11:07 PM

Grampa – LOL
It WILL suck in pine smell – as soon as it’s warm enough to open the window!

The blower seems to work fine in this position. NO vibration or any nosie (rubbing etc.). I do think mounting on rubber helped a lot.

Thanks for the kind words…

-- James - I don't like jogging - the ice pops out of my glass...

View Grandpa's profile


3264 posts in 4012 days

#6 posted 04-26-2011 11:52 PM

Thanks for the post and thanks for the information. I was curious about the mounting and the noise if there was any. This is great. We have been in the lower 90’s a few times this year already (SW Oklahoma). I smell pine needles everytime I ready your blog and look out your shop window.

View DIYaholic's profile


19921 posts in 4011 days

#7 posted 04-27-2011 01:45 AM

My shop air cleaner is currently being designed in SketchUp (I need the practice). I’m planning a dual purpose design. 1) Run of the mill air cleaner. 2) Fresh air blower for Paint/Finishing room. I will be building a plastic tent/room within a room. I will have an attachment for the clean air exhaust that will provide positive pressure into the “plastic tent”. The benefits will be two fold; 1)isolating the motor from combustible fumes and 2) prevent dust from contaminating the finish.

After seeing your dual purpose cleaner, I may make mine a tri-purpose machine by making it either an infeed/outfeed table or a stand for planer/bench tools.

Thanks for posting your air cleaner, it has given me food for thought regarding the design of mine.

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

View gfadvm's profile


14940 posts in 4026 days

#8 posted 04-27-2011 05:07 AM

What a great build! It looks like it was purchased from Grizzly! I love the multipurpose idea. Im probably going to steal this idea.Thanks for posting it.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View bigike's profile


4059 posts in 4625 days

#9 posted 04-27-2011 05:18 AM

great job.

-- Ike, Big Daddies Woodshop, http://[email protected]

View JWags's profile


64 posts in 3997 days

#10 posted 04-27-2011 12:43 PM

Thanks again eeryone for the comments!

Randy – I’d love to see your Sketchup about this. I really hafta learn that system.
gfadm – Steal away – I’d like it if you posted yours – especially if you improved it.

-- James - I don't like jogging - the ice pops out of my glass...

View patron's profile


13722 posts in 4677 days

#11 posted 04-27-2011 03:04 PM

great work there james

i too wanted to build my own
but couldn’t find a fan for it
so i bought a HF unit and winged it

here are custom (and standard) filters i did find

here is electrostatic air filters
hose wash
last a lifetime
1 to 3 micron filtering
buy once
last forever

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View rodman40's profile


166 posts in 3663 days

#12 posted 05-02-2014 12:56 PM

Hi James, Nice work on the air filter, I have some questions about the wiring setup 1- does it run on 220 volts or 120 volts 2-do you have 3 speeds or just one 3-what size wiring is the motor 4-do you have a timer, I want to build a filter for my shop and need the info so I can start, I bought the blower units from a guy but he had cut the wires as close to the motor connections as possible. he said they were out of 220 air conditioners. Thanks in advance, rodman

-- Rodman

View jgt1942's profile


336 posts in 3225 days

#13 posted 05-18-2016 10:59 PM

It looks like you are pulling the dust through the squirrel cage. Just a small amount of dust on the squirrel cage will greatly reduce the air flow.

-- JohnT

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