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Shop air filtration build - Advise welcome

Posted: Fri Dec 27, 2019 11:22 pm
by Chuck Tweedy
I've been planning on getting a shop air filtration system, and almost bought one for myself for Xmas. By coincidence, someone at my day job bought a used military transport HVAC air handler. It had 4 blowers in it and he sold me 2 of them ... for a song. and i can't sing, so that's sayin' sumthin'.
they are Embpapst, German made, units that can do 700 cfm. At only 6"x12". And they are not used, they are brand-spanking-new.

So I need to build a hanging shop air filter(s) around them. My sinuses will thank me.
I'm thinking that its best to make 2 smaller units and put them on either side of the shop, where I spend most of my time.
I've been looking at the construction of units like the Jet, and I see that they have a big (deep), bag-like, internal filter.

Has anyone made one of these units from scratch? Has anyone used any specialized filters?
If you had to do it again, what would you have done.

Check out my blowers!

Re: Shop air filtration build - Advise welcome

Posted: Fri Dec 27, 2019 11:55 pm
by Bob Gramann
This is what I did. It sits on the floor and blows up to the ceiling. I use the 3M Filtrete 1900 filters. I have a duct that I attach to it when I spray to blow the fumes out the window (the box containing the guitar to be sprayed backs up to it in the front). A timer shuts it off so I can clean the air after I leave the room.

Nice blowers.

Re: Shop air filtration build - Advise welcome

Posted: Sat Dec 28, 2019 12:20 am
by Chuck Tweedy

Re: Shop air filtration build - Advise welcome

Posted: Sat Dec 28, 2019 9:48 am
by Bob Gramann
That would be it. Lowes gives a discount when you buy 4. All sizes cost the same, but you get more filter surface the bigger the filter. I use the 20x25. I took one apart. The pleated filter was 8 feet long.

Re: Shop air filtration build - Advise welcome

Posted: Sat Dec 28, 2019 4:22 pm
by Randy Roberts
Chuck,

May not apply to your garage shop situation, but I remember many years ago Mario posted about his system.
It involved using the space between the studs as his ducting.
I think he converted the door of a floor level cabinet to hold the filter(s), so it drew off the lowest air in the room, had the fan itself in the cabinet, vented up the wall between the studs since that gave him a couple of pre-existing 3 1/2" x 16" ducts [studs plus drywall] and vented it back into the shop at the top of the wall by cutting a slot in the wall's drywall.

I loved the idea at the time, but then my wife developed serious allergies to sawdust, and I abandonded working at home.

Re: Shop air filtration build - Advise welcome

Posted: Sat Dec 28, 2019 8:52 pm
by Chuck Tweedy
Hey Randy, I did remember that Mario had done something clever (imagine that :O).
I'm not going to be able to do that, I don't have any free wall space.
These are going to be up on the 8' ceiling. Above my work island so nobody can hit their head. And the blowers are small, so they can be low-profile.

Great to hear from you - hope all is well.
I hope to be building with some figured walnut soon (not going to count the years).

Re: Shop air filtration build - Advise welcome

Posted: Sat Dec 28, 2019 9:58 pm
by Randy Roberts
Oh geez, Walnut Rescue. I'd forgotten. not to sidetrack the thread, but I gotta ask, do you still have the video of when you were resawing it and trying your best to cover your surprise at the un-oxidized yellow wood that appeared?
I'd give my eye teeth to watch that again.

Re: Shop air filtration build - Advise welcome

Posted: Sat Dec 28, 2019 10:26 pm
by Chuck Tweedy
Still on Youtube buddy.
Now i can count the years more easily. Oh boy.

Re: Shop air filtration build - Advise welcome

Posted: Sun Dec 29, 2019 2:06 am
by David King
I've been getting furnace filters from nordicpure.com and they make some 3" and 4" deep pleated filters that will way outperform the 1" type in longevity and available in any MIRV rating you desire. True HEPA is around MIRV 16-17. You can get activated charcoal if you want to deal with schmelly wood at the same time.

Re: Shop air filtration build - Advise welcome

Posted: Sun Dec 29, 2019 2:36 am
by Chuck Tweedy
David, thanks for pointing me to nordicpure - they have just what i'm looking for. you just made my boxes much smaller and easier to make.

Re: Shop air filtration build - Advise welcome

Posted: Sun Jan 12, 2020 3:41 pm
by Chuck Tweedy
I made progress on my filter units after the NordicPure filters showed up Friday.
Below is the bid from the front. I made them from plywood material i have just laying around - The face piece has a purple plastic veneer.
The 2 rectangular holes are where the air comes out - and boy, those blowers can push a hurricane of air.
Behind the unit I've placed the "guts" of what is in the box.

Re: Shop air filtration build - Advise welcome

Posted: Sun Jan 12, 2020 3:43 pm
by Chuck Tweedy
The rear with the "guts" in view.
The guts are the blower, a 24 volt DC power supply, and the filter.

Re: Shop air filtration build - Advise welcome

Posted: Sun Jan 12, 2020 3:57 pm
by Chuck Tweedy
And finally, just the back.
So far the filter is just duct-taped on to the back of the box - which is designed to be the same OD as the filter.
Here's the thing...
Thanks for bringing up NordicPure, but I am NOT impressed with them.
The filters are supposed to be MERV13, which should be filtering small particles at a high efficiency. But the filter media on these is not great. It is not even as thick/dense as the filters i usually get for the house (Honewell), and those are not rated as high. I also bought some filters for the house since I was on the site and i needed some. They are supposed to be MERV14, but it is the _same_ media as in the 4" deep ones.
There simply is not enough density of filter media in these to be what they claim to be. Beware.
So what? So, I'll get some better filters of the same 20x10 dimensions and work from there.

Anyhow, the general design is good. I still need to mount the unit on the ceiling.
I have a potentiometer poking out of the box so i can easily control the blower speed, and i have a pressure port so i can monitor the back pressure of the filters (these have almost NO back pressure)

Re: Shop air filtration build - Advise welcome

Posted: Sun Jan 12, 2020 11:59 pm
by Barry Daniels
Are you going to put some binding on it? ;-)

Re: Shop air filtration build - Advise welcome

Posted: Mon Jan 13, 2020 5:06 pm
by Randy Roberts
And where are the rosettes on the exhaust ports Chuck? Shoddy, shoddy work if you ask me......

Re: Shop air filtration build - Advise welcome

Posted: Mon Jan 13, 2020 7:38 pm
by Chuck Tweedy
No, no binding, no rosettes. Much thanks for the back-handed compliments tho - appreciated and noted.

I am, however, going to put them on remote control on/off.
I will be building the second one ASAP, and will be adding Filtrete 1900 secondary filters.

So everyone can breathe a little easier - i know you were concerned. :geek:

OH! and I will be building with some beautiful figured walnut that was rescued just a few years ago. Stay tuned.

Re: Shop air filtration build - Advise welcome

Posted: Mon Jan 20, 2020 9:38 pm
by Phil DiVuolo
I have a Jet. In the manual it suggests that the unit be hung from the ceiling and along a wall. This keeps the air circulating in a circular pattern.

Re: Shop air filtration build - Advise welcome

Posted: Mon Jan 20, 2020 10:54 pm
by Chuck Tweedy
Follow-up:
System is complete. I have made 2 boxes, added Filtrete 1900 2nd-ary filters, hung them on the ceiling, and put them on remote control.
They are in opposite corners of the shop - pointing so they circulate the air in the room. It is real nice.

Re: Shop air filtration build - Advise welcome

Posted: Tue Jan 21, 2020 11:26 am
by Barry Daniels
I'm a contrarian so I put my filter on the floor. I figured that dust settles so may as well put the filter where the most dust is.

Re: Shop air filtration build - Advise welcome

Posted: Sat Feb 01, 2020 8:02 pm
by Chuck Tweedy
Hey all, i must have posted when the update was going on and it got lost.
Basically, I have these units up by the ceiling because that is where i have space. I agree that collecting down by the floor would be more productive, but I'm trying to keep my lungs clear. The dust that is suspended in the air is what i need to catch - and i think these are doing that.
Thanks for looking!