Indoor laser exhaust/air scrubber

[Anthony Scira]

I made my move and the laser made it without a scratch !

Only problem I am having now is the place we are renting and I can't modify the structure for a exhaust.

And since its hot in Temecula I would hate to exhaust all my nice cool air out the window with a blower. So I would like to scrub the air, I know they sell factory units but they are 3 to 5 k and the filters need to be changed often.

Are there any homebrew ideas out there ? I cant seem to find any online.

[Dave Johnson29]

Are there any homebrew ideas out there ? I cant seem to find any online.

Anthony,

This was discussed early this week or last week. Also do some searches here as there have been quite a few built and described here. Dan Hinz was making one IRC.

[Dan Hintz]

How much do you want to spend, and how much do you want to clean the air before it hits the filters (to increase their life)?

For a quick and dirty version, pick up the following:
1) Plastic kitchen garbage can
2) Three 4" diameter flanged duct stubs
3) Some 1/4" hardware cloth (wire mesh)
4) Shop vac filter (regular or HEPA)
5) Activated charcoal
5) Caulk and/or expanding foam
6) Duct tape

Cut a 4" hole in the side of the garbage can near the bottom. Insert and seal one of the flanged duct stubs into the hole using duct tape and caulk (flange inside, stub sticking out). Place a 6" square section of hardware cloth over the hole (inside) and seal.

Do a similar move with the garbage can lid, the remaining two duct stubs, and more hardware cloth. This time, one stub should point out of the lid and one points inward. The chop vac filter should wedge onto the inner duct stub (you may need a different diameter stub based upon the filter you purchase).

Weigh the garbage can assembly (I'll explain why later), and fill can with 25-50 pounds of charcoal, leaving enough room at the top for the filter/lid combo to be properly inserted. Seal the lid gap with duct tape (allows the lid to be removed later for replacement of the charcoal).

The bottom duct connects to your laser cabinet, and the top duct connects to your blower. You can reduce the amount of large crap that makes it into the filter by placing a layer of furnace filter (washable electrostatic filter, generally blue in color) in front of the entire system.

Total cost should be under $150.

If you want to preserve filter life even more, you can add a true (electronic) electrostatic filter setup before the charcoal filter. However, this electronic filter itself will cost between $400-$600, and it will require some more complicated custom ductwork to properly neck down/up the airflow between laser->filter and filter->charcoal. Even so, total cost should be under $700 if you're able to bend the sheetmetal yourself. Due to the up/down necking, this option will also more than double the amount of space required to house the entire system. With some creative design, you can place the two filters side by side or top over bottom, and I suggest putting it all on a platform with wheels for easy moving.

What you have created is nothing more than a less compact version of those all-in-one filtering systems that cost north of $5k.

Once you have finished, weigh the garbage can with the charcoal in it to determine how much charcoal you put in. About once a month (depending upon usage), weigh the garbage can assembly. When the charcoal has doubled in weight, it's time to replace it as you have reached the basic limit of its ability to collect fumes.

That's it! Inexpensive at 1/30th the cost of a commercial unit, not to mention filter refills are significantly cheaper.

[Dave Johnson29]

For a quick and dirty version, pick up the following:
1) Plastic kitchen garbage can
2) Three 4" diameter flanged duct stubs
3) Some 1/4" hardware cloth (wire mesh)
4) Shop vac filter (regular or HEPA)
5) Activated charcoal
5) Caulk and/or expanding foam
6) Duct tape


Geeze Dan,

I had a deja vu moment there of Apollo 13. :D:D:D

[art baylor]

Pictures would be good.
Art

[Anthony Scira]

Thanks Dan that is perfect. As I build it I will take some pictures and post them here for refrence.

Thanks again !

[Dan Hintz]

If my memory holds up, I'll try to get some pictures this weekend. I've been spending a lot of time trying to get another couple of studwalls up in the basement so I can start installing a second bathroom, so little time to play with the laser.

[Vaughan Raymond]

I've seen people on the forum talk of using barbque briquets as activated carbon. I don't think they are really activated. If these don't work, where do you get activated carbon?

[Randy Digby]

Here is the link to a thread I started a few weeks ago when I was building my scrubber. George and I both listed suppliers - his had a much better price. There is some good info in the thread.

http://www.sawmillcreek.org/showthread.php?t=116592&highlight=scrubber