DIY Air Scrubber

[MAYOR28]

I have been planning on putting in an air scrubber from the very beginning of my build plans. I was not really sure how I would accomplish it, but I was inspired by a deal I couldn't pass up. A local HVAC contractor said that they would be happy to give me a furnace/heater out of a house that was simply upgrading to more efficient unit.

BINGO! I have an entire 'working' heater/blower to play with.

The plan is to mount it in the ceiling of the compressor room with an inlet on the door side (for common air filters) and an outlet on the window side. Should be able to circulate some good air through there.

(old pic, but still in the same place, lol)

I had originally planned to just use the blower motor, but instead I am just going to throw the whole unit up in there, then build plenums to the inlet and outlet.

The slickest part, is I think (if I am reading the wiring diagrams right) there is already a 24V transformer inside for control. I plan/hope to run the 24V control lines down to a timer circuit (any ideas how to do this), so I can turn it on for set times, and/or just an on/off switch.

Something likes this?

 

[MAYOR28]

I also found a good deal on some 2" thick filters locally. Should keep my stocked for a while.

 

[Terranova]

I built one into a rolling clamp rack that houses the blower motor I had.

https://www.garagejournal.com/forum/showthread.php?t=256086&page=8

Post 150.

I don’t have room to hang stiff from the ceiling and I made it rollable in order to be able to position it closer to what I was working on.

 

[Earp69]

Sorry to ask a dumb question but what's the purpose of this air scrubber?

 

[MAYOR28]

Sorry to ask a dumb question but what's the purpose of this air scrubber?

Not a dumb question. Clean dust (mostly sawdust) out of the air.

I tend to dabble in woodwork, but not enough to warrant a dedicated/plumbed dust collector. Therefore, I plan to find a cheap dust collector to use as a giant shop vacuum, and use the scrubber to extract the dust out of the air.

I am hoping if I run it occasionally too (1-2 times per week), it will keep the general dust down in the shop.

...

 

[MAYOR28]

I built one into a rolling clamp rack that houses the blower motor I had.

https://www.garagejournal.com/forum/showthread.php?t=256086&page=8

Post 150.

I don’t have room to hang stiff from the ceiling and I made it rollable in order to be able to position it closer to what I was working on.

Nice, that is a great combo-unit. And I do like the idea of a mobile clamp rack.....although I am not sure I have the space for it.

 

[dogdog]

might be too high up to be effective ??? no ? Nice Garage and Stair case look really good.


as far as controlls...

I would want a wifi controllable ones maybe with / without timer...

There was a hack for those Sonoff switches maybe you can google that up...?

 

[MAYOR28]

might be too high up to be effective ??? no ? Nice Garage and Stair case look really good.


as far as controlls...

I would want a wifi controllable ones maybe with / without timer...

There was a hack for those Sonoff switches maybe you can google that up...?

I will have to look into the Sonoff stuff, I had never heard of that.

The compressor room (white door in the picture) is only 10 feet tall, so the intake will be around 8' high. Most of these type scrubbers are meant to hang from the ceiling, so I am hopeful it will work for the airborne dust particles.

...

 

[nadogail]

IMHO, because sawdust and the fine dust from sanding are weighty particulates, perhaps your scrubber (which I like the idea of) would be more effective with inlets closer to the source of the material to be scrubbed or at a lower level than the ceiling because of the effect of gravity on the stuff you want to scrub from the air.

 

[Kaizen]

I will also be doing something like this but just as an exhaust. No filters but using nice quiet rabbit cage blowers.
I like having the ability to click it on and get smoke or sawdust moving out. Probably going to start with one trunk and see how it will go. I try to reduce sound like corner fans roaring all the time. Interested to see how yours turns out.


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[couch67]

I built one a few years back using an old single stage blower. behind the black filter is a bag filter that goes a long way between cleanings. Between it and a dust collector, it does a good job of keeping dust down.

Just a simple switch but I've thought about putting it on a timer or remote, one day...

 

[brownbagg]

the 24v transformer for the outside compressor, all you need is 110 for fan and a switch

 

[InsanePyro]

I'm assuming you removed the heater element from it? Just a giant fan blowing at your filters?

 

[zkdiesel]

Mines wonderful. Has huge squirrel cage in middle. Blows cleaner air out front. Has a restriction gauge

Uses 4” think 24x24 furnace filters in each side then large bag filters behind those. Works wonders for air quality and dust buildup.

Mines at height but hangs from barn door slider track and can move it 40’ side to side in building closer to work or out if way if I need overhead room

 

[NUTTSGT]

Just food for thought. I have a 14x20 filter on the blower for my wood furnace. I get about 3 weeks out of a filter. I am using a cheap white pleated filter from Menard's. If I do any grinding of paint, metal or spray painting, the filters do not last as long.


Don't be surprised if you go through filters rather quickly and I'd suggest easy access to swap them out.

 

[Firebrick43]

A filter like your building is a good investment in your health. You really need a hepa filter last stage to remove the small <10 micron particles that are harmful to your long term health. Larger partial are a nuisance(they should still be filtered) as you can typically cough them up. Use a cheap filter or two to keep the hepa from plugging up prematurely.

The biggest thing to note is you should not think that the filter replaces the need to wear a respirator while wood working. It takes a long time to brings the air levels down after sawing wood with power tools.

 

[PelicanPines]

My uncle had one in his makeshift spraybooth. Large box fan on one end... sealed to a box with a 5" house filter. He had a 1" prefilter too... wish he changed the filter more often... but it certainly captured stuff.

 

[Jeff Ivers]

I made one a few years ago that was a roll-around unit with fresh air sucked in the front through 2 stacked 1" filters and then filtered air out the top. It did help with air quality, but I eventually sold it because I did not like the floor space it was consuming. I used a cheap filter in the front with a hepa type filter behind. I could burn through several cheap filters which collected most of the pollution before needing to change the hepa. Build is documented in my DIY shop thread. One thing to keep in mind is whether the furnace blower was updraft or downdraft. I had to do some internal re-arranging to get the air in the direction I wanted. If I had taken the time to design this to mount to the ceiling and set the intake up so that it was remote from the unit, it would have been more useful.

 

[slackdaddy1]

I just picked up a used Aprilaire ERV for 400
plan to have a 16x16 "pre-filter"

 

[Earp69]

I would like to make one that vents to atmosphere but my only hangup is making it seal up good when not in use during winter, most louver setups I've seen aren't that great at actually sealing and would be a decent continious heat lose

 

[zkdiesel]

I would like to make one that vents to atmosphere but my only hangup is making it seal up good when not in use during winter, most louver setups I've seen aren't that great at actually sealing and would be a decent continious heat lose

The negative vacuum you create in your building is also a huge thermal loss

 

[Earp69]

The negative vacuum you create in your building is also a huge thermal loss

Yeah I'm aware but I have radiant floor heat so it would recover quickly since all the objects in the barn are heated up not just the air. Would be nice if your painting or grinding etc just to kick it on for a few minutes.

 

[Kaizen]

Yeah I'm aware but I have radiant floor heat so it would recover quickly since all the objects in the barn are heated up not just the air. Would be nice if your painting or grinding etc just to kick it on for a few minutes.

Exactly my plan. You can make a large sliding plate shutoff like a dust collection shutoff. At the wall should stop exterior air coming in


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[MAYOR28]

Just food for thought. I have a 14x20 filter on the blower for my wood furnace. I get about 3 weeks out of a filter. I am using a cheap white pleated filter from Menard's. If I do any grinding of paint, metal or spray painting, the filters do not last as long.


Don't be surprised if you go through filters rather quickly and I'd suggest easy access to swap them out.

Good advice, thanks!

I picked up 12 of these for $20! Hoping with a dirt cheap on in front of this, they will last a while, but maybe that is wishful thinking......

 

[MAYOR28]

A filter like your building is a good investment in your health. You really need a hepa filter last stage to remove the small <10 micron particles that are harmful to your long term health. Larger partial are a nuisance(they should still be filtered) as you can typically cough them up. Use a cheap filter or two to keep the hepa from plugging up prematurely.

The biggest thing to note is you should not think that the filter replaces the need to wear a respirator while wood working. It takes a long time to brings the air levels down after sawing wood with power tools.

This!

 

[QwikKotaTx]

I use a programmable temperature controller I got off eBay to run a furnace blower as an attic vent fan. It has a thermocouple that triggers the circuit at 90 degrees or whatever I set it to and pulls a lot of air. It helps remove heat from the space above my ceiling which I am going to insulate soon. Turns off when it drops 2 degrees below set point. I think it is good for 15 amps. I haven't found a good way to mount it in a wall plate junction box but looks easy for a flat sheet metal panel.

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[NUTTSGT]

Good advice, thanks!

I picked up 12 of these for $20! Hoping with a dirt cheap on in front of this, they will last a while, but maybe that is wishful thinking......

All you can do is try it, test it and modify it. Hope it works well.

 

[MAYOR28]

I'm assuming you removed the heater element from it? Just a giant fan blowing at your filters?

I haven't removed it, but I am going to bypass the heater circuit to power just the blower. If I ever wanted to, I could use the heater to extra ooompf, or for another purpose (who knows), so I don't want to throw it out.

...

 

[Bmwtie]

Here is mine. Took inspiration from shophacks.com but did my own thing. It uses five 25x20x1. I am lucky to have 15’ ceilings. Also I used a wifi plug so i can just turn it on with alexa while in the garage.




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[MAYOR28]

It lives!!!!!


I was able to turn the blower on with just the thermostat wires. But I didn't realize there was a built in time delay for startup and shut down. Took me a while to realize this, I assumed connecting the thermostat terminals would fire the blower right up. Then as I was standing there scratching my head, then all of a sudden it started up!

...

 

[nerraw117]

i normally take the board out and use house switches for powering the motor. different colors are different speeds. I normally use low and high.

 

[MAYOR28]

i normally take the board out and use house switches for powering the motor. different colors are different speeds. I normally use low and high.

Do you run the high and low to 2 separate switches? That way you can choose one or the other?

(if not, that is interesting, and maybe I should try that......)

 

[MAYOR28]

I would like to add a bag-style filter to the mix, but I cannot seam to find the right name for these filters. Anyone know where to buy these by size? Or know how big the Grizzly H9622 is for the G0572 Air Filter is?

 

[brownbagg]

heat pump unit.

i guess filter get clogg pretty fast and with them not being cheap. I wonder if a water bath filter could be invented

 

[nerraw117]

I run one (1) way switch for one and off. and a three way switch for the low and high.

 

[MAYOR28]

I run one (1) way switch for one and off. and a three way switch for the low and high.

this is a great idea!

what kind of 3-way switch?

 

[MAYOR28]

heat pump unit.

i guess filter get clogg pretty fast and with them not being cheap. I wonder if a water bath filter could be invented

I meant the filter name.

 

[nerraw117]

go to a hardware store and get you a work box that will hold 2 switches. make one a one way and the other a 3 way (they look identical but function differently (applies power to the common post on the 3 way switch. then you can make one direction one speed and the other direction another speed.

this is a great idea!

what kind of 3-way switch?

 

[MAYOR28]

go to a hardware store and get you a work box that will hold 2 switches. make one a one way and the other a 3 way (they look identical but function differently (applies power to the common post on the 3 way switch. then you can make one direction one speed and the other direction another speed.

 

[glend123]

I built this one with an old blower motor. it is about 12 x 20. it has 3 regular pleated furnace filters and a piece of filter material fastened to the front.