Fume Extraction

[Soren Christensen]

Hi guys,

I know there are a few posts around (along with tons of YT vids regarding this) but I need another solution, that the DIY fume extractor.

So heres the background:

I have been searching high and low for a decent place to setup shop, but no luck. So I thought that i would keep it at home. However, I live in a flat, so at the time I was thinking about getting a fume extractor. But the more I looked into it, the more $$$ it seemed to cost.

So today I actually had a epiphany and noticed a hole in my kitchen (we arent able to have an extractor hood in the kitchen, something to do with the building being old) which usually "vents" out smoke and stuff after cooking. So I thought to my self. "That would be the optimal place to vent out from the laser".

To give you an idea about the layout of the kitchen ( i have attached a picture of the layout)

kitchen layout.jpg

NB: the height of the room is 8.43 ft.

So what I was thinking, was to run ducting from the laser and opwards to the cealing, along side the wall and then plug the duct into the "vent" hole, thus venting out above the apartment (above the roof) and not out of the windows.

Only thing is. I need to figure out how I actually should pull it off and which kind fan, I would need to make sure the air gets pulled well enough from the laser and pushed through the system and out the hole.

Is there anyone that could give me a few pointers or atleast let me know if this is even possible to accomplish?


Any ideas or tips would be greatly appreciated

[Nick Marchesani]

I was looking at fume extractors today. I checked home depot and saw these. At the bottom of the page there are many more.

https://www.homedepot.com/p/VENTS-22...-150/204629634

[Soren Christensen]

I was looking at fume extractors today. I checked home depot and saw these. At the bottom of the page there are many more.

https://www.homedepot.com/p/VENTS-22...-150/204629634

unfortunately, im not in the US But it gives me an idea about, what I need

Also, im guessing i would need some kind of insulated ducting, to prevent the air noise through the ducting

[Steve Utick]

If you have access to Amazon deliveries, they sell a line of inline duct fans under the name of AC-INFINITY that a lot of guys are moving to. They are VERY quiet and move quite a bit of air. Might be something to look into.

[Joe Adams]

unfortunately, im not in the US But it gives me an idea about, what I need

Also, im guessing i would need some kind of insulated ducting, to prevent the air noise through the ducting

I just went through this setting up my Trotec Speedy 300 80w.

It turns out that there's a lot of science involved with understanding air movement dynamics. Unfortunately, neither the laser makers nor the ducting and fan manufacturers were able to offer very much help in figuring out a properly sized system.

Trotec was able to give me the minimum airflow rating at the exhaust port of the machine expressed as a certain amount per minute at a specified pressure. My interpretation was that inline fans did not operate at a high enough pressure to meet this requirement so I went with a radial blade centrifugal fan. That being said, there are a number of members here who use inline fans.

The size, length, and number of bends in the ducting make a big difference. You also want smooth walled ducting for less resistance.

I didn't want to hire an engineer to design my system so I followed the consensus that it's better to have too much airflow rather than too little. This is tricky in an air conditioned or heated space as the treated air will be removed and is replaced by outside air seeping in.

It also depends on what you are cutting or engraving. I was told by multiple people that rubber is the worst in terms of odor.

[Kev Williams]

Just a note on airflow and lasers... Not sure about Trotec but Gravograph's draw air from directly behind the table, thru a 3/4-ish inch wide slot, with the 4" duct exit directly behind that. Works great, in that it draws air across the table. However, fast-moving smoke-filled air being moved across the part(s) your engraving can get covered with the particulates in the smoke. This is bad when engraving any Rowmark signage with a white core, among other things. At night, I started using a quieter blower with only about half the suction on my LS machines to keep a neighbor happy. I found a benefit, in that all my engraving and the entire work surface was cleaner. The lower velocity of air moving lets much of the smoke drift upwards away from the work. The only downside is it takes a few seconds longer to clear all the smoke. Lens doesn't need more cleaning...

Conversely, on lasers like my Triumph, where smoke evacuates UNDER the table, by all means get all the air movement you can afford! You need as much velocity to keep smoke from drifting around above the work for long periods of time, which can collect on the mirrors and lens, which can lead to this-
lensbroke.jpg

The nice thing about too much airflow, you can always temper it down with a blast gate. But there's nothing you can to do make a low flow blower move MORE air

[Soren Christensen]

I just went through this setting up my Trotec Speedy 300 80w.

It turns out that there's a lot of science involved with understanding air movement dynamics. Unfortunately, neither the laser makers nor the ducting and fan manufacturers were able to offer very much help in figuring out a properly sized system.

Trotec was able to give me the minimum airflow rating at the exhaust port of the machine expressed as a certain amount per minute at a specified pressure. My interpretation was that inline fans did not operate at a high enough pressure to meet this requirement so I went with a radial blade centrifugal fan. That being said, there are a number of members here who use inline fans.

The size, length, and number of bends in the ducting make a big difference. You also want smooth walled ducting for less resistance.

I didn't want to hire an engineer to design my system so I followed the consensus that it's better to have too much airflow rather than too little. This is tricky in an air conditioned or heated space as the treated air will be removed and is replaced by outside air seeping in.

It also depends on what you are cutting or engraving. I was told by multiple people that rubber is the worst in terms of odor.

I see your point.

So rather something, like this:



And not something like this:




What about the air noise? Is that considerable or tolerable?

Also regarding the fan, i would be setting up a control for it, to be able to adjust speed, so that I can experiment with the smoke clearing I've asked my manufactor to list the min required CFM needed at the exhaust.

[Soren Christensen]

If you have access to Amazon deliveries, they sell a line of inline duct fans under the name of AC-INFINITY that a lot of guys are moving to. They are VERY quiet and move quite a bit of air. Might be something to look into.

Only thing is, that I would have to prevent the fan from becoming cluddered with all sorts of debris from the laser.

Or would i simple, just clean it once in a while?

But I have looked at the inline fans and they do offer a pretty good CFM and a very reduced sound lvl

[Steve Utick]

Only thing is, that I would have to prevent the fan from becoming cluddered with all sorts of debris from the laser.

Or would i simple, just clean it once in a while?

But I have looked at the inline fans and they do offer a pretty good CFM and a very reduced sound lvl

Any fan that you're using will need to be cleaned once in a while. How often will depend on what you are cutting. If you're cutting a lot of wood, you will get residue on the blades that necessitates cleaning more often. Any screen or anything you put inline to try and prevent that will clog up sooner, reducing your airflow and compounding problems. The AC-Infinity fans come apart very easily for cleaning as well.

[Kev Williams]

Just want to mention that I'm not much of an 'overthinker', and I really don't care about 'pretty'...
...All I care about is that my stuff works.

That said, just wanted to show off MY fume extraction 'system' (lol) --the garage version--
shopa.jpg
I took this pic standing at door to my garage shop, my 2nd ebay fiber is directly to my right out of view,
and my rotary tool cylinder engraver is to my left. On the back wall of the garage hangs
a cluster*&$! of vent hoses from bulk red wiretie and bent welding rod. Just plain old
dryer vent, 3, 4 and 6", one splits between my GCC Explorer and the fiber you can't see, the other line
splits between the big Triumph laser and my Triumph fiber right in the middle of the pic.
Each duct line has a gate, and 2 HF blowers sitting outside under the plex garage window
inside a plastic patio storage box do all the extracting...
blwr1.jpg
I can generate a ton of smoke and ash at times, and it all gets sucked away just fine

[Soren Christensen]

Just want to mention that I'm not much of an 'overthinker', and I really don't care about 'pretty'...
...All I care about is that my stuff works.

That said, just wanted to show off MY fume extraction 'system' (lol) --the garage version--
shopa.jpg
I took this pic standing at door to my garage shop, my 2nd ebay fiber is directly to my right out of view,
and my rotary tool cylinder engraver is to my left. On the back wall of the garage hangs
a cluster*&$! of vent hoses from bulk red wiretie and bent welding rod. Just plain old
dryer vent, 3, 4 and 6", one splits between my GCC Explorer and the fiber you can't see, the other line
splits between the big Triumph laser and my Triumph fiber right in the middle of the pic.
Each duct line has a gate, and 2 HF blowers sitting outside under the plex garage window
inside a plastic patio storage box do all the extracting...
blwr1.jpg
I can generate a ton of smoke and ash at times, and it all gets sucked away just fine

I love your little maker space To hell with the clutter

Btw, do you have any problems with the flex hoses? I mean some people say that the ducting should be with the most smoothes surface?

[Soren Christensen]

Any fan that you're using will need to be cleaned once in a while. How often will depend on what you are cutting. If you're cutting a lot of wood, you will get residue on the blades that necessitates cleaning more often. Any screen or anything you put inline to try and prevent that will clog up sooner, reducing your airflow and compounding problems. The AC-Infinity fans come apart very easily for cleaning as well.

Only thing left, is really at which end do I need to put the fan? Close to the machine or at the exhaust venting out? Pros and cons?

[Kev Williams]

I love your little maker space To hell with the clutter

That's just the garage, you haven't seen the basement

Btw, do you have any problems with the flex hoses? I mean some people say that the ducting should be with the most smoothes surface?

Speaking of the basement:
TheAbyss(custom).jpg
this pic, which was laser engraved by my LS900 onto 1/8" thick NON-laserable New Hermes black/white '2-plex', I did about 7 years ago. All of the silver ductwork sprawled all over the ceiling is still there, and was about 8 years old when I took the pic! I'm sure it doesn't move as much air as smooth PVC would, but seriously, since it's just moving smoke, the improvement wouldn't be all that noticeable...

[Soren Christensen]

Speaking of the basement:
TheAbyss(custom).jpg
this pic, which was laser engraved by my LS900 onto 1/8" thick NON-laserable New Hermes black/white '2-plex', I did about 7 years ago. All of the silver ductwork sprawled all over the ceiling is still there, and was about 8 years old when I took the pic! I'm sure it doesn't move as much air as smooth PVC would, but seriously, since it's just moving smoke, the improvement wouldn't be all that noticeable...

How about air noise? Is it noticeable or not?

[Steve Utick]

Only thing left, is really at which end do I need to put the fan? Close to the machine or at the exhaust venting out? Pros and cons?

The fans are designed to pull air, not push it. You're better off putting them closer to the vent.