Greetings Laser Family,
Looking for some inspiration for fume extraction. I know I can drop quite a few
How do you deal with the fumes? Show me/us your setup with photos
And where you got it, how much etc…
I don’t want to spend $3000
Cheers
Sasquatch
Omg… hold my beer.
You’ll want to see mine, but pictures aren’t good enough…
I need to think. Also… it’s not that expensive
In a box at the side of the house. It’s outside so that the pipes coming from the laser (and the laser itself) are under vacuum so no fumes can escape into the room with the laser. Any leaks will leak into the pipes.
Made from a cheap leaf blower. It was supposed to be temporary while waiting for a proper blower, but it’s been working fine for a year now even when it was -20C. It has a trigger lock and a built-in speed controller which is set to about 3/4 power. It’s very powerful and has no problem pulling fumes over 30’ of 4" tubing and many bends and restrictions.
It blows into the air about 10ft above the ground. Even when cutting large amounts of acrylic you barely smell anything walking around outside, unless standing right at the extractor. Definitely no odour from the sidewalk or back yard. It’s quite loud though.
It’s controlled by a 15A remote power switch with fob. This also was supposed to be temporary but it’s been working fine.
Total cost is under $200.
I’m designing a filter at the moment but can’t show anything yet. My laser is located in a small building at the bottom of my garden. It’s been fine over the wet and windy winter but I was horrified a couple of days ago when I left my partner to look after the laser while I went back in the house and returned to see the vertical plume of smoke in the calm air! It looked like I was having a barbeque! But didn’t smell as enticing. I can’t now use the laser as everybody is outside in the sun because of the current lockdown.
My device is relatively simple; A box manufactured from 19mm MDF. A clip on removable front panel. Air from the laser enters the bottom and travels vertical through layers, all arranged in slide out trays. First it encounters a prefilter made from 20mm filter material used in air conditioning and paint spray shops and bought by the Metre off Ebay. (£14). Next is a HEPA filter layer. This uses two side by side filters from a room purifier ( “Replacements for Idylis HEPA Style A / B / C /D Air Purifier” I bought size D at £17 each). Next is a 3" deep tray of activated carbon. I intend to wrap in a layer of fly screen material as I have a roll and it looks like it will stop too much carbon falling out. I paid £95 for 25Kg of activated charcoal from online. The air exits through a top layer of the same 20mm thick prefilter material to capture any charcoal dust. The air is removed from the top of the cabinet by my existing in line centrifugal fan. It’s a large and powerful speed controllable beast with a 6" rigid duct. I just hope it works! If I could get better HEPA filters I may in time so for now I’m leaving space for better later if needed. I have been unable to get better at the moment due to everywhere being closed during this Covid shutdown. Time will tell.
Hello,
I am using a powerful fan (800m3 / hour) with a speed controller.
This fan is connected to 150mm spirotube. I have a small pre-filter installed towards the roof blowout which filters a lot of the nasty stuff and smell. I also installed a valve to make sure there is no unnecessary cold air getting into the room during the winter. The fan is really silent for the amount of air it sucks out of the laser enclosure and the variable speed makes it really nice to tweak the RPM.
For now that is it, but I am able to construct some sort of filter box on top of the roof in the event neighbors complain about smell when sitting outside in the summer. I do not cut anything besides wood, but you never know.
You can create such a filter box yourself. Get yourself one or more pre filters and a active carbon filter. That will filter a lot of the bad stuff.
Here are some pictures of my current setup:
Just set this up today - I’ve had my laser for about two days, and this is the first practical application I’ve put the machine to. My shop has a 20" ventilation duct that’s apparently a leftover from a previous tenant that had a plasma cutter table.
I needed to hook up a 6" flexible duct, so I made this adapter with three 6" holes, and put a duct starting collar in one hole. The idea was to leave the other holes for future use, including a hood over the welding table (which is current directly below the duct).
This thing sucks, and not in a bad way. I’m probably going to redo it to have four holes because with only two open there’s too much suction. The whole length of flexible duct rises up when the fan is turned on, and even with the machine powered off the build-in exhaust fan spins so fast I’m afraid it’s going to wear out. Clears the air in the machine in a hurry, though. Not sure what the blower is rated at, but next time I’m on the roof I’ll check the nameplate.
No filtration yet. So far I’m mostly just cutting plywood, and the smoke is vented three stories up on the roof so smell isn’t really an issue.
Hi Les
I’m also looking at a similar approach. Have you had your set up running? and did your extractor fan cope with the increased resistance of the various filters.
I purchased a carbon filter intended for grow rooms and my fan just lacked the power to pull the fumes through. Having read about the different types of fans it seems I need one with high static pressure which has lead me to this
It looks super efficient with 2 fan and 2 filters, but I think you need to build a pair of pre-filters in your system, preferably before the fans and the activated carbon filters, or you get them clogged quickly.
I have them. They are wraps the prefilter the sawdust. Currently one is drying. There are better fans out there, but only really available on amazon for UK. Also about $450 US or more. I already had the 4" so figured why not?
They’re separated so they won’t work against one another. They’ll be pulling from the vent on the bottom for the bottom, and the top (which should really be the 6" fan but I’m using the stock one as well below) will pull from vents up top. Best I can do with limited space, tools and money. I will take video once I get the rest of the parts.
This opens easily for service or adjusting mirrors etc. Going to have to vacuum every few hours or so to keep things clean and flowing.
But thank you!
EDIT: Complete now except ducting. Can run full test and clears smoke as quickly as it makes it. Only need 1 or 2 minutes before opening door. Need to track best places to vent and I think it’s production time. I’ll upload final pics before and after I paint it.
I’m about to order a fan for my DIY build. I’m currently looking at the Prima Klima 150 EC Blue:
https://primaklima.com/en/ventilation/ec-ventilators/150mm/pk150-ecblue/
It is a 1100m3/h fan. But I know nothing about the static pressure etc. Can anyone recommend this fan? Or maybe give a recommendation for something similar? Due the location of my machine and exhaust the noise level is pretty important for me.
Static pressure is also known as system air resistance, and it is essentially a measure of the resistance to airflow that occurs in the HVAC system. Symptoms of a static pressure issue include excessive noise, hot and cold spots in the home, and even equipment failure.
In other words, how strong is the fan motor when there’s air that needs to be pulled or there’s something in front of it when it needs air to be pushed into it. The stronger the fan motor the better.
1100m3 /hr is the same as 647 CFM.
https://www.easycalculation.com/unit-conversion/m3h-to-cfm-calculator.php
On the surface it appears to be similar to what I have but an 8" version. Most of the 8" inline duct fans are a little stronger actually.
The one I linked is a 6” (150mm). You have a 8”? Do you think 647CFM is sufficient for a 90W 100x50cm Laser?
I have roughly 640CFM minus the filters. It’s currently going full blast and I’d suggest a bit more if possible. But if really depends on the SIZE of your machine, length of burn and filter. If you have the room, and if you’re going to vent into the workspace get a better filter than I bought. Mine is fine for outside venting but leaves some to be desired although it’s really miniscule overall.
I’ll vent outside using a pretty short hose and no filter. My machine isn’t extremely large, so I’ll take my chances and order the one I mentioned. I’ll post the result as soon as my machine is ready.
That should be fine. I’d create a dust and scrap collector at the bottom though.
So, one thing I don’t understand:
My machine will be 150x40x70 cm. Which is 0,42m3. If a fan blows 1000m3/h that means that it refreshes the air in the machine 2381 times per hour. Which is 40 times a minute. Isn’t that waaaaaay more then necessary?
Why should I aim at 1000m3/h? Shouldn’t I be focusing on a specific number of times the volume of my machine can be replaced per hour?
There is a good point of view on this topic. And it is also worth noting that the same amount of air that is being sucked out must also be added again! Therefore, it is also not the right way to go to hermetically close a laser machine that has proper extraction. Useless underpressure is produced with too high energy consumption for extraction.
I think it’s covered in one of the articles, but yes, you need air in as well. I’m still figuring out the best spots for vents in. And in the end it might end up being near the far end of the laser tube.
That depends on how much smoke you produce. On my test cuts even with fans on full it still fills the machine up. It’s going to be a work in progress.
I’m not an HVAC guy and there doesn’t appear to be one in the forum. I’d love to hear from them. Overall I think yes, you should focus on replacing the volume of air.
Yeah I definitely will add a proper air intake. But then still, I think the need for 1000m3/h is a somewhat arbitrary number.
I watched some videos of the AC infinity S6 fan. And while it doesn’t have a huge static pressure and doesn’t reach 1000m3/h I’m convinced this should be enough if the machine has proper air intakes.
Of course it also comes down to the type of usage. I won’t be running it 24/7. And will mainly be cutting. Not engraving.
Time will tell if my stubbornness will bite me in the butt once again. 
