DIY air filtration unit for <$200

[Randy Digby]

Great design Dan, and thanks for sharing. My design is a little different but the one thing I have learned that might help in any design is that I now use cheese cloth to surround the charcoal. It does not restrict air passage and makes removal/exchange of the charcoal much easier, at least with my design.

The pics sure help - thanks for taking the time to show and tell.

[Dan Hintz]

I now use cheese cloth to surround the charcoal. It does not restrict air passage and makes removal/exchange of the charcoal much easier...

I'll add it in during my next charcoal swap... I just need to lay down one layer and leave the edges long. Come time to swap, gather the edges and pull the whole package out.

[Randy Digby]

That's exactly what I do. Before the cheese cloth, I had to carry the scrubber down to the garage to change charcoal because of the dust. I leave the ends long, like you say, and simply gather the sides together and lift the charcoal charge out and replace in the same manner.

[Dan Hintz]

Now to FIND some cheese cloth... <opening up Google.. tap tap tap...>

[Mike Chance in Iowa]

Now to FIND some cheese cloth... <opening up Google.. tap tap tap...>

Grocery store. Baking aisle.

[Niklas Bjornestal]

Why not put the HEPA filter before the active coal? The main function of the active coal is to remove chemicals from the air and not particles, so it might be better to filter out as much particles as possible before the coal.

[andrew zen]

Great idea!! Where did you get the bulk activated charcoal? From an aquarium store?

[Dan Hintz]

General Carbon... there are a few useful selections, but I got the 55 lb bag of their C-30. The bag was $96 with $19 ground shipping.

[Randy Digby]

Reference the HEPA prior to the charcoal, in my experience, the charcoal actually filters out some solid matter that makes it through the furnace filter pre-filter which presents cleaner air to the HEPA filter. This, I think, greatly extends the life of the HEPA filter, which is the most expensive item in the assembly. Others may have different experiences.

I actually removed my HEPA filter from my system and started venting back outside to save the cost of the HEPA filter replacement. The main purpose of my scrubber is to remove the smell since I live in a close residential neighborhood. But then again my HEPA filter was 12" x 24" x 12" and ran close to $400.00 each.

I like Dan's set-up. I built mine out of 1/2" MDF. His is much easier to construct.

[Mike Null]

Your point is a good one. In my previous life we used metal mesh filters ahead of the charcoal to protect the charcoal filter from solid particulates thereby extending the life.

I have a hepa filter on my vac but don't know if it has odor reducing qualities like charcoal.

[andrew zen]

Apparently our friends who are into growing ganja, have this filtering all figured out so that people don't smell their growing plants.

http://www.hydrofarm.com
http://www.rollitup.org/indoor-growi...on-filter.html

Search eBAY for "carbon filters" or "Carbon air scrubber"

There are a lot of DIY projects on the web using ductwork/ aluminum fencing and carbon fernace filters. But I think Dan has a good way.

[Bob D.]

Was NASA your inspiration on this filter build? You didn't by chance
just finish watching Apollo 13 before you put your filter together did you?

In all seriousness nice job.

http://www.youtube.com/watch?v=Z3csfLkMJT4&NR=1

[Robert Walters]

FWIW...

27 lbs of 4mm pellets == 1 cubic foot.

[Robert Walters]

Was NASA your inspiration on this filter build? You didn't by chance
just finish watching Apollo 13 before you put your filter together did you?

In all seriousness nice job.

http://www.youtube.com/watch?v=Z3csfLkMJT4&NR=1

Bob++

Classic!

Bonus Karma for that!!!!!

[Steven Wallace]

Dan what was your source of the charcoal?