Fume considerations for lasers

Hi,

in my quest to get my big delta laser ready I want to get the enclosure that is capable of handling the laser fumes. From what I read those are more agressive/dangerous than just the particle emissions from normal printing, so a real ventilation is necessary I think.

I looked a bit around for chemical fumehoods but those are quite expensive. I also read about a shopvac with a ashfilter which seems reasonable to me as its at least transporting most of the air out. But running this monster is probably a bit overpowered and not noise and electricity efficient. I wonder if a used resonable sized kitchen fumehood would do with an exhaust out of the windom? I theory a fan on each side of an airduct should do as well [www.amazon.com].

Whats are your solutions and what where you looking for when you designed you air system?

Cheers

Any good fan with enough airflow will do.
Same for the enclosure, use acrylic if you need to see, wood or metal if you don't care.
If it is not a CO2 or a diode on a similar wavelenth you need to make sure to have safety glasses for that wavelenth.
For CO2 basically any will do as the light is absorbed by both glass and most plastics.

ok thats sounds good. there are safety glasses in the kit and since I have a 40x100cm delta I was thinking of a rain barrel that might get a acrylglass window for right wavelength.

what air volume are you moving with your system?

All I can say is that there is never enough airflow
But jokes aside:
How much airflow you really need depends on several factors:
1. Are you using air assist? If so the air volume from that needs to be added.
2. How sealed is the machine? Leaks and open areas make extraction hard to impossible, you only want the air inlet to be open and equipped with a filter if you are in a dusty workshop.
3. What material are you using and how much power on the laser? For serious cutting jobs you will need a high flow, maybe in the top end of a good range hood.
4. Last but not least: Direct outlet or filtered outlet into the same room? For a filtered system you might need more pressure so again a higher volume fan.

Those ceiling ones for bathroom and laundry to a good job but they are quite noisy.
A vacuum cleaner won't last long as they are not designed for ongoing use and again too noisy.
Extraction fans as used in hydroponics are quite good and the noise level on a smaller fan is not too bad.
Best option IMHO is a long centrifugal fan with a speed regulator attached.
Requires some custom housing but they are almost silent and provide massive air flows.

Good considerations you mention there.

1) Ill proabaly use my model cooling fan for air assist and im mostly doing plastic and from my test with my local fablabs laser cutter it doenst have the tendency to burst into flames. but it can be added if necessary.
2) How do you mean that? I was debating if the air that comes from all the leaks is enough of an intake or if I should lay another dedicated input duct. I I think the former should be enough. I dont do any other woodworking in my "shop" so no need to filter the input.
4) direct outlet out of the windows seems easiest for starters.

I have my eyes on those hydroponics fans, compared to the fumehoods they have much more bang for the buck and they fit directly on to the duct work.

1. get a compressor for air assist, a fan won't help to prevent burning. I used a 10$ one that I got from the scrap out of an old fridge, works great and is silent.
2. I mean that if you have a lot of holes in unwanted areas you will have a problem sucking the smoke out where it happens.
It is best to have the air intake somehwere so the incoming air goes over the work area and out of the exhaust fan.
4. I agree, but warn your neighbours that there might be some burning smell every now and then - I had mine knocking on the door when I did a lot of MDF cutting.

If you are looking into the hydroponics fans try to get one that can be regulated in the speed.
Most are fixed and powerful but can't be regulated with a dimmer or similar.
Reducing the fan speed by just 20% still gives more than enough sucktion but reduces the noise by at least 50%
Might be worth to consider if you have the fan somewhere near you.

1. it seems I have to ask the supplier about that. the laser is weak (2W) so an aquarium pump might even do
2. makes sense, i thinking of using a rainbarrel for that so i can control the leak or intake holes well.
3. that will be an interesting conversation

the fan speed reduction is already on my list for the hotend fan. a bigger fan that can run slower for the same volume. ill keep speed regulation in mind