Homemade Air Purifier

[jay913]

In my opinion, this is the most important tool on my bench.

 

 

https://youtu.be/T0WAnV_R8X0

[Bob Blarney]

How many filtration layers, and what pulls the air through it?  

[jay913]

3 filtration layer, (pre-filter->HEPA Filter->activated carbon filter),

I m using 2 used DC 12v PC fan to pull the air.

decrease the voltage to control the air flow.

A Very simple design, quite easy to build. The only disadvantage is the filter aren't re-useable.

[Captain Al]

So what do you actually do with this contraption?  Do you set it up behind the work and pull the air away from you?  Do you actually have your work on top of this uneven surface as you sand, drill, glue or whatever?  It looks good and I'm definitely in the market for some kind of air filtration system (been coughing for 4 months now and may have to give up the hobby entirely), but I can't get a handle on how this system works.

[Mike Y]

There is definitely a market for benchtop air filters that could be just put on the back side of the workbench, pulling air through the filter. The main problem is getting a powerful enough, but quiet motors and propellers.

[jay913]

Captain Al:

I just put it on my bench, pulling the dust away from me. Generally I switch it on no matter why I do, sanding, working with CA glue and epoxy, soldering. when sanding, I always turn the voltage up to 12v to increase the air flow in order to filter as many air bound particles as possible.

Normally, I keep my purifier runs @ 7- 9v , less air flow and a bit quieter.

 

 

Mike Y:

brushless PC cooling fan is very quiet.

but when the air is pulling through the filter, that is going to generate some wind noise.

 

My Purifier's Noise level @12v : (65-70 dB)

brushless Fan without filters : ( 55-60 dB)

 

[Captain Al]

OK, now I understand how its used.  My solution so far has been a regular old fan that blows the air and fumes away.  I realize that there is no filter to catch any of it so I try to blow it out through an open garage door.  I'm thinking now that maybe just set up some filters (in a frame or not) and try to catch the wind as it passes.  My fan would probably blow the filters over.  So, I keep on trying; and coughing.

[Pete38]

put the filters on the suction side of the fan and draw the air through them. That is what I do when sanding and seems to work pretty good. I just use a cheap window box fan.

[Bob Blarney]

It's hard to suggest solutions without knowing much about the workspace.  Generally, dust and fume collection is most effective when the inlet is close to the source of contaminants, but then the noise of the fan can be annoying or even fatiguing.  For a tabletop modeling setup, it would not be too difficult to make a ducted system  that allows remote location of a box fan or a bathroom vent fan. On one of my workbenches for sanding small items and letting painted items dry, I  use a furnace register box with a 4" fitting as an inlet, connected with dryer duct (rigid Sch 30 PVC pipe would be better here) to a box that contains the filters and the fan.  The fan exhaust  can be directed out of the building by conventional dryer ducting.  But a word of caution is in order here:  Although letting painted articles dry is ok, >>DO NOT spray paints or varnishes<< with volatile vehicles with this exhaust system.  Although the danger of explosion is probably remote in a hobby installation, it's still possible and the consequences could possibly be severe.