Out to air extraction

[Mark Ward]

I know the topic is a well covered one and I've done plenty of reading up but I'm now after getting some external extraction sorted to replace the Trotec Atmos that we are currently using which is stupidly expensive for replacement filters and carbon.
I have attached a picture of where our laser (Speedy 300) is located, the wall on the left (by the window) is where I am thinking we can go straight out from, if we move the Atmos that is next to it out of the way and put the laser in the corner instead would this work OK or would we be best turning the laser 45 degrees to try and get the extraction straight out with no bends or would a single 90 degree bend in the pipe and then fan and straight out from there work OK?
From bit's I've read some have suggested this fan although the description says "where noise is not a great concern." so I'm guessing it's loud then (not ideal), better options?
The other I'd heard of was: Axminster AWDE5002 I presume you take the bag off ont h is one and pipe straight outside.
Also, would the current Trotec piping fit or is there somehting to change the pipe/ducting size to make it fit?
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[Gary Hair]

For that short of a run I wouldn't worry about bends, it's not going to make a bit of noticeable difference. In my current office I have 3 90's into the blower and then straight through the roof, altogether it's about 20' long - the cheap Harbor Freight green blower clears the smoke out just fine. Oh, and I've also got it hooked up to my two fibers that add a 45 and two 90's into the mix - still works fine.

[John Lifer]

He's in the UK, no Harbor Freight. The Axminster is pretty much the same as our Harbor freight cheapie. But I think the centrifugal is going to be quieter.
I'd probably go that route.

[Michael Hunter]

As John Lifer says, the centrifugal fan is likely be be the quieter - I would guess MUCH quieter!

I have a centrifugal fan (not the same model) and it makes a fairly strong whooshing sound, but it is bearable for day-long use.

The Axminster type of fans have blades optimised for dealing with wood shavings etc. rather than quiet operation.
The Axminster extraction system at the boat yard where I visit gets turned off the moment it is not needed as, even though it is mounted outside the building, the noise is unbearable!

[Mark Ward]

Thanks for the replies guys, it is very much appreciated and thanks for clarifying that the centrofugal option looks to be the best route to go.
Probably a silly question, is it the larger 150mm end of the fan that is the laser facing and the 60mm end that is external facing or the other way round?
I'm trying to figure out about connecting it to the laser as the existing pipe from the Trotec to our Atmos has a diameter of 80mm so need to figure how these will connect into the fan.

[Bruce Clumpner]

Going to have to test that, but one point on positioning the fan. Put it as far down-stream from your laser as possible. That way any leaks in your ducting will only pull clean air into the exhaust, and not push exhaust back into the shop, like it will if it's a long run from the fan to the outside.

[Andrew Holloway]

Thanks for the replies guys, it is very much appreciated and thanks for clarifying that the centrofugal option looks to be the best route to go.
Probably a silly question, is it the larger 150mm end of the fan that is the laser facing and the 60mm end that is external facing or the other way round?
I'm trying to figure out about connecting it to the laser as the existing pipe from the Trotec to our Atmos has a diameter of 80mm so need to figure how these will connect into the fan.

The fan looks to have 150mm inlet and outlet.
I use 100mm flexible ducting coming straight off my Trotec outlet. Just keep screwing the hose clamp down and the 100mm happily becomes 80mm.
In the past I have used PVC pipe for my exhaust and ran 100mm pipe up to the laser outlet. I wrapped a few layers of thin spongy foam around the laser outlet until it was about 100mm size, an elastic band held that in place, then the PVC just slips onto it, it was not even close to a perfect seal but I had more than enough airflow and it allowed me to easily disconnect and reconnect. You could use duct tape if you don't need to disconnect it often.

[Andrew Holloway]

And I would highly recommend the Axminster over the centrifugal. I haven't used this one but I have never found a centrifugal with nearly enough airflow. When I changed from the biggest best 150mm centrifugal to one similar to the Axminster, I went from having to clean my optics at least daily to once every week or 2. And time spent cleaning the inside of the laser has been halved.
And yes, you just take the bag off :-)

[Mark Ward]

And I would highly recommend the Axminster over the centrifugal. I haven't used this one but I have never found a centrifugal with nearly enough airflow. When I changed from the biggest best 150mm centrifugal to one similar to the Axminster, I went from having to clean my optics at least daily to once every week or 2. And time spent cleaning the inside of the laser has been halved.
And yes, you just take the bag off :-)

What is the noise situation like with the Axminster? We're going to be working in the same room right by it and I thought I read somewhere it's like a plane taking off?!

[Rich Harman]

Best thing to do, IMO, is build an enclosure and place the fan outside. Solves both the potential leaking problem and the noise problem.

[Kev Williams]

This Axminster-
bl1.jpg
and this Harbor Freight unit
bl2.jpg
---are radial fan blowers--

this thing is a 'squirrel cage' blower...
bl3.jpg

All 3 of them are are centrifugal blowers...

=================

These are axial fan blowers--
bl4.jpg

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I have a pair of small squirrel cage blowers (a Stanley and some blue one )- they're very quiet, all you hear is air- however, they're small with a small motor all encased in plastic that doesn't resonate like the metal housing with big electric motor versions. Furnace blowers move air without being too noisy, so the cage type may be quieter than the radial type. But the noise my HF blowers make isn't deafening by any stretch, most of the noise is the housing resonating the noise of the motor and air moving, and they're just not that loud. The one I have outside the basement door runs nearly all day every day because just the cooling fans of the other machines drown out the blower noise, so I don't know it's even running!

[Sean Kirkpatrick]

Hey Op, just checking to see what you decided to do for a ventilation system? I'm looking to purchase the trotec 360 and the rep said the Atmos Duo (at $5900) is required but I'm pretty sure thats because he wants to add the upgrade.

[Mark Ward]

Hey Op, just checking to see what you decided to do for a ventilation system? I'm looking to purchase the trotec 360 and the rep said the Atmos Duo (at $5900) is required but I'm pretty sure thats because he wants to add the upgrade.

We've changed to out to air extraction, we originally used our Atmos for 3 years but it's rediculously expensive to change the carbon and filter and as we really only engrave and cut wood no harmful gasses so happy enough to extract outside.
DSC_1229.jpg

[Sean Kirkpatrick]

I see you've gone with pvc. what are the benefits over actual galvanize vent piping?

[Mark Ward]

No idea. Surely it's all about getting a solid tight fixing between pipes.