Hi all,
Due to increased housing where I vent my laser, I am looking at options for filtering the fumes before sending them outside. There are 2 options I am looking at, one (more expensive) option is a unit that has a built in extraction fan, while the second (much cheaper) option is just the filters in a unit that connects to my existing extraction fan. Does anyone have any experience/insight into these types of units?
You’ll have to show me what you mean. None of my lasers had any kind of filter in the machine.
One of the problems you have is that some filters don’t filter out some of the bad gasses and sometimes smell.
What usually people complain about is having to change out a $300 filter every week or two.
Some have built filter boxes with common filters they can get at the big box stores, in them to get rid of the biggest debris particles before venting it out. Others vent the diy box into a filter system, so the diy gets most of the large debris that clogs up most filters, thus extending the commercial filter life.
I suggest you don’t use multiple fans, you end up with the least efficient fan limiting your cfm.
Unfortunately, there is no simple solution to the venting issue.
Good luck
You can get industrial sizes of carbon filters on amazon or a local grow supply.
Using a smaller pre filter and then activated carbon can really reduce the smell.
How often do you use your laser?
What are you cutting/engraving?
How big is your vent/ fan ?
Thanks guys. I wouldn’t be using multiple fans: Option 1 (cheaper) retains the existing fan, but pushes the air through the fume box before it is expelled. Option 2 (more expensive) replaces the existing fan as it has one built in. To me I can’t see how this is any different but the price difference is quite a lot?
Both have multiple filter layers so I don’t see any difference there.
I am leaning towards to cheaper one as I don’t see any real benefit to having the all in one unit?
Yes both options have multiple layers of filtration as you mentioned.
Currently not using the laser very often, but I would like to get more use out. Usually cutting plywood, mdf, acrylic
Hi.
I haven’t made (/converted, I have a few options stored) one for my laser yet, but in my past life I used to balance large and small HVAC-systems, and the bascics are exactly the same:
A fan-unit (or a two if make-up air is required), combined with various stages of filtration and treatment, housed in a box or a few.
The unfortunate fact is that an effective and at least reasonably quiet fume-/smoke extraction system is not going to be cheap.
And unless the inside temperature and humidity in Your shop can follow the outside temperature, a make-up air system with its own filtration and treatment stages is required.
Any filtration will inevitably reduce the airflow, which in turn will increase the noise.
The more effective the filtration, the larger the pressure drop, the greater the demand for fan power, and as a result the louder the noise.
If You have the tools and the skillset to whittle out an air handling unit, You can save a pretty penny.
Or alternatively dumpster dive or buy a second hand household air handling / HV(AC) unit, and convert that for smoke treatment duty.
If You have the space, using the industrial size filter units @soniclab mentioned, will make life a lot easier, not to mention a lot cheaper.
OTOH if You don’t have the space, Your quest will become significantly more expensive in the long run.
Good luck, You’re going to need it 
.
Regards,
Sam
You can search here in the forum, this topic has been on the table many times. The summary has always been that you need to invest heavily in professional equipment to be able to clean the exhaust gases from a laser machine that processes acrylic or MDF/HDF.
I have built a filter system myself based on an industrial exhaust and 2-3kg of active carbon filter segments. The result is fine, the first few days… After a few filter changes, which are expensive, I have removed the filter unit and blown the dirty smelling air directly into nature. Unfortunately, this is the only option I (many) have. If there is a possibility to build a chimney, it is clearly an advantage. The distribution over the roof height of the house helps to distribute the “problem”. But of course it is not optimal. If one of my neighbors starts complaining about the acrylic smell, I will have a problem.
Thanks for the reply. Yeah that does seem to be the conclusion on most of the things I have been reading too, that to do a semi decent job requires $$$. In fact most of the recommended units cost more than what I paid for the laser cutter itself!
I can’t find a lot of info on the cheaper (I say cheaper, but even this is still a lot of money) unit though, and I just wonder what the performance would be compared to the all in one units.
These are the x2 different units I am looking at:
This is the one that is filters only:
This one has the inbuilt fan
I think they look nice and they should work…, but…, acquisition and operating costs require a profitable order backlog.
I have a small shop vac from harbor freight that exhausts into a 5 gallon bucket with aquarium charcoal and aquarium filter floss that I got from chewy. I put a light dimmer on the vac to make it quieter and control the vacuum. I drilled a hole in the lid of the bucket and a lot of smaller holes for the air to escape. It is all under the table my laser table.
You have this vented into the room you occupy, not outside?
Note that positive pressure applied to any indoor part of the system will confirm there is no such thing as an airtight joint.
Source: Been there, have that. 
I vent it to the room. It is charcoal filtered so there is zero odor. When I start smelling it, I change the charcoal. I put about 3 gallons of charcoal in the bucket. Lasts over a year. https://www.chewy.com/marineland-black-diamond-activated/dp/125921
Yes I have read about that too. I believe placing the extraction fan after the filter box is one solution as it would mean any leaks get drawn into the system instead?
The ideal spot for the blower is on the outside of the wall putting suction on everything inside the building.
I have an inline blower sitting next to the laser with four feet of double-lined hose downstream to the vent. Even with two taped joints on that hose, the air inside still gets a bit aromatic.
Fortunately, it’s in the basement and that side of the house at ground level is reasonably well sealed …
I have a ThunderLaser Nova 24 60W CO2 laser. I have experienced the same issue and wanted to cleanup the discharge of my machine. I recently purchased a Monport 350watt filter. I have only used it for about 5 hours but the discharge of my machine has been significantly reduced. It is not vented outside and I smell no foul odors in my shop as well as zero smoke. Time will tell if the filter media needs to be changed often and at what expense.
Ok thats good to hear it works well for you! The units I am looking at are similar to what you have there
This unit looks great and it’s good to hear that it works in real life. If you only have to replace the HE+ME+ME filter 4 times a year (ca.$1300???), - it’s a option for cleaning the air in the workshop.
It would be great if you could keep us updated on how your filter system is doing. Can you tell us what materials you process in your laser and how many hours per week your filter is used? (Monoport states “service time” as 2-6 months, which is too flexible for an honest calculation)
Thanks
I usually cut/engrave plywood, acrylics, solid wood like walnut and oak. I recently cut/engraved about 125 leather patches for a client. I will admit there was a little odor with the leather but not nearly as bad as before the filter.
My ThunderLaser Nova 24 runs about 8-10 hours a week. Not a lot by some standards but nonetheless a good amount of time. My shop is climate controlled but in when temperatures are nice the doors are open.
