[joshpit2003]

Hey guys.

I'd been doing a little more research on blowers and filters.
I'm getting a laser that has a 2' x 3' cutting area and comes stock w/ a 6" exhaust port.

I'm concerned about noise and smell,
so after searching online for "quiet" blowers, I noticed the grow-up guys are using similar equipment.

I've seen blowers for grow-ups that range from 450-750 CFM and are "very quiet".
Some of 'em even have speed-controllers, which seems like a nice feature for when I'm cutting material that doesn't stink or smoke so bad.

These grow-up guys also sell in-line carbon filter, pre-filter, and duct-silencer systems.

I was just wondering:
- Does anyone on here have any experience w/ using grow-up blowers/filters for their laser setup?
- What's an ideal CFM rating?

Thanks.
-Josh!

[BrianJenkins]

Are you able to duct it outside? That's your best bet, unless you want to deal with the charcoal filters. Here's writeup for one: DIY air filtration unit for <$200 - Blogs - Sawmill Creek Woodworking Community

I use a Tjernlund M-4 (200 CFM) on my small 40W unit and it was a huge improvement over the stock fan. For a larger laser, I'd get the M6 and you can always add the speed controller to it

[joshpit2003]

Thanks for the link.
Great to know a measly "200 CFM" works on your small machine.
Yeah, I'm going to be ducting it outside, either w/ 6" or 8" duct.
I'm trying to get a gauge for what CFM's work and what don't.

-Josh!

Are you able to duct it outside? That's your best bet, unless you want to deal with the charcoal filters. Here's writeup for one: DIY air filtration unit for <$200 - Blogs - Sawmill Creek Woodworking Community

I use a Tjernlund M-4 (200 CFM) on my small 40W unit and it was a huge improvement over the stock fan. For a larger laser, I'd get the M6 and you can always add the speed controller to it

[BrianJenkins]

Thanks for the link.
Great to know a measly "200 CFM" works on your small machine.
Yeah, I'm going to be ducting it outside, either w/ 6" or 8" duct.
I'm trying to get a gauge for what CFM's work and what don't.

-Josh!

The cost difference between the larger sizes was only about $10...but a 6" fan was around 500 CFM. If your duct run is short you can get away with something smaller. If its going to be long I'd skip the inline fans and look as a cheap dust collector (but having it blow outside).

It really depends on a lot of things. Keep in mind though that you may be removing conditioned air outside of the building in either summer or winter. So if the building is really tight its going to be harder to extract.

Some mount the dust collector outside to minimize the noise. I'm planning on putting my fan in the attic and duct through the soffit.

[joshpit2003]

thanks for the tips.

I'll be ducting it nearly 20 feet vertical.
Why a dust-collector instead of an in-line?

[agrasyuk]

Smell. depends on what you cut , acrylic that i mostly work with smells a lot. i know some just exhaust outside, but unless you are in your own industrial building your neighbours might still complain. i find that smell of acrylic is very presistant and travels quite far, so IMHO some sort of filtering is absolutley required. personaly i'm not risking it.

Noise. good induction motors are very quet , i find that most of the noise comes from the sheer amount of air moved. how is your blower and ducting is constructed will influence ithis a lot - air whooshing past the exhaust grill is tolerable , but still very audible in my case.

CFM. several members here voice different figures based on their experience. after trying several solutions (starting with bathroom fan and then to some light industrial stuff) i don't see how anything below 600CFM can be sufficient for acrylic and I firmly believe the more the better. my current solution is based on blower fan from whole-house HVAC unit, rated at round 1200~1500 CFM, but a lot of that CFM lost to carbon filter and duct bends restrictions. that motor has several windings allowing for 5 speeds of operation, after trying various speeds i dropped the idea of speed selector and hardwired the highest one. fan is timer activated and runs for half hour or so after i end the job.

some may find this over the top, and maybe it is, I don't insist. just like i don't insist on others to wear job apropriate protective gear, as long as it doesn't involve others (and as long as it is not in my workshop), I believe it is god given right of anyone to cause harm to himself if he so wants.

[BrianJenkins]

Dust Collector systems move a lot of CFM because of their setup and how large the impeller is.

More CFM is more noise though. Try and mount the fan closest to the exit point and keep your bends minimal.

[joshpit2003]

Thanks guys for all the feedback.

After a good deal of online research I've narrowed my search down to the following:

Possible Blowers:
Phresh Hyper Fan 8" - 710 CFM - ~$170
https://www.monstergardens.com/phresh-hyper-fan-8-inch

Phresh Hyper Fan Stealth 8" - 710 CFM - ~$270 (comes with a build-in duct silencer)
https://www.monstergardens.com/Fans-...8-inch-710-CFM

Max Pro-Series 8" - 863 CFM - ~$200
Can-Fan Max Fan Pro Series 8 in - 863 CFM - Megagrowers.com


Possible Filters:
AirBox3 8" - 1500 CFM - as low as ~$350
Air Box 3 Stealth Edition 1500 CFM 8" Flanges

Phresh Inline 8" x 24" - 750 CFM - ~$240
https://www.monstergardens.com/Fans-...8-x-24,-750cfm

Obviously these are all 8", but the machine comes with 6". I may just enlarge the 6" opening on the machine to be 8", or perhaps (would love an opinion on this):

I could cut a 4" hole ABOVE the cut-table, and splice that into the 6" duct coming from the bottom of the machine.

Thoughts?

[MechanoMan]

It is unlikely ANY of these inline blowers will work. Laser cutters use significant static pressure drops, cutter mfgs often specify 6". That is, you have to develop a partial vacuum at the inlet.

Like, a box fan, you cover the inlet completely, you don't develop a high vacuum and you get no airflow. A vacuum cleaner develops a lot of suction when covered, though. Opposite case.

Inlines are like the box fan. You restrict the inlet much and the airflow declines steeply. An inline fan rated at 800 cfm, when put on a laser cutter, might drop down to 150 cfm and less than 1" of static pressure. It can't draw any more.

Centrifugal fans are much better at developing high static pressures. But not all. A 2HP dust collector is pretty decent, but may still be substandard. We did try an expensive, quiet hydroponics blower. Guess what, next to 0 airflow out of that laser cutter. Useless for this application.

[Bsrlinmaz]

Another thought regarding putting your fan outside: if the fan is drawing the air from the machine and through the duct work to the outdoors, if there are any small leaks in the duct work the air will be drawn in, and out the exhaust. If you mount the fan near the laser and are "pushing" the air out through the duct work, if there are any small leaks then the air and smell, etc. will be vented out at the point of the leak, and possibly into the building rather than outside.

Hope that makes sense as I described it.

[MechanoMan]

Another thought regarding putting your fan outside: if the fan is drawing the air from the machine and through the duct work to the outdoors, if there are any small leaks in the duct work the air will be drawn in, and out the exhaust. If you mount the fan near the laser and are "pushing" the air out through the duct work, if there are any small leaks then the air and smell, etc. will be vented out at the point of the leak, and possibly into the building rather than outside.

Hope that makes sense as I described it.

Sure it makes sense. But I do note this- laser cutter smoke is pretty hard on blowers. It builds up concretions on the blades and spoils the airflow. If it's an inline with an internal motor, the concretions will cake onto the motor, reducing its cooling and causing it to overheat, and/or contaminating the bearings.

To avoid that, you'd have to put the filter before the blower. That's still possible to put filter, blower, then the inside-the-building ductwork.

[KeithOKC]

Sorry but I have to jump in here. That's a complete exaggeration. There are people on sawmillcreek that have been using their blowers for 12 years to exhaust their lasers. We've used ours for 2+ what you're stating as fact, may happen over many many years but it's not likely for a very long time.

Sure it makes sense. But I do note this- laser cutter smoke is pretty hard on blowers. It builds up concretions on the blades and spoils the airflow. If it's an inline with an internal motor, the concretions will cake onto the motor, reducing its cooling and causing it to overheat, and/or contaminating the bearings.

To avoid that, you'd have to put the filter before the blower. That's still possible to put filter, blower, then the inside-the-building ductwork.

[KeithOKC]

I don't see a lot of details about your run, feet, turns etc, or your laser. But if it's a single laser setup Penn state and harbor freight have decent blowers for the money. Could also look into shop fox or grizzly.

Thanks guys for all the feedback.

After a good deal of online research I've narrowed my search down to the following:

Possible Blowers:
Phresh Hyper Fan 8" - 710 CFM - ~$170
https://www.monstergardens.com/phresh-hyper-fan-8-inch

Phresh Hyper Fan Stealth 8" - 710 CFM - ~$270 (comes with a build-in duct silencer)
https://www.monstergardens.com/Fans-...8-inch-710-CFM

Max Pro-Series 8" - 863 CFM - ~$200
Can-Fan Max Fan Pro Series 8 in - 863 CFM - Megagrowers.com


Possible Filters:
AirBox3 8" - 1500 CFM - as low as ~$350
Air Box 3 Stealth Edition 1500 CFM 8" Flanges

Phresh Inline 8" x 24" - 750 CFM - ~$240
https://www.monstergardens.com/Fans-...8-x-24,-750cfm

Obviously these are all 8", but the machine comes with 6". I may just enlarge the 6" opening on the machine to be 8", or perhaps (would love an opinion on this):

I could cut a 4" hole ABOVE the cut-table, and splice that into the 6" duct coming from the bottom of the machine.

Thoughts?

[MechanoMan]

Sorry but I have to jump in here. That's a complete exaggeration. There are people on sawmillcreek that have been using their blowers for 12 years to exhaust their lasers. We've used ours for 2+ what you're stating as fact, may happen over many many years but it's not likely for a very long time.

The system does pick up significant crud. Whether it deposits on the blades is a complicated question of where it is in the system, flow rate, blade shape, blade composition, blade velocity, etc. And type of material being cut, for sure!

I've definitely seen some buildup on our centrifugals. Not serious, but I'd rather not have an inline motor exposed to that. Also centrifugals, from what I've read, are the least likely to pick up debris anyhow.

When befuddled by ULS/Epilog's "6 inches of static pressure at high CFM", I really didn't see any blower approaching that- even 2HP dust collectors. I did see regenerative blowers were capable of higher statics like that. But what I also saw was regens need CLEAN air, and laser exhaust sure didn't seem to meet that, not without a filter anyhow.