Would this be OK ventilation for a Full Spectrum 5th gen laser?

[Lynn Dixon]

Hello all! My first post :-)

I have just bought a Full Spectrum 5th gen laser, and I am getting it all setup. I am trying to find a good way to vent it outside without creating alot of noise. I have a 1hp Dust collector, but that thing is LOUD when I am using it. I am using 4" flexible metal ducting from the laser all the way to a dryer vent on the exterior wall. Its probbly only about a 7 feet total run if I had to guess.

I am looking for a much quieter way to vent my laser outside, and I stumbled across the ventilation fans that people use for "indoor gardens". This one has a ton of reviews on Amazon and seems like it might do the trick:

http://amzn.to/1b7Qp2Q

It pushes 400 CFM, and I only need about 100 CFM (per the FSLaser documentation) to vent my laser. The reviews say its pretty quiet for the amount of air, and one reviewer keeps it on in his bedroom while he sleeps.

Has anyone had any experience with these inline blowers? Any good recommendations?

Thanks!

[Dave Sheldrake]

Very good bits of kit but no pulling power on long duct work, fitted at the back of the machine into a short vent is fine but their pull drop rapidly with any tube added.

cheers

Dave

[Gary Hair]

Lynn - CFM is an important number but you also need to know the static pressure (I think that's what it's called anyway). A computer CPU fan can push 300 cfm but the power behind it (static pressure) is very low. Same thing with the "grow" fans - lots of volume but not much power. I know DC blowers are loud but they are designed to move lots of air, and more importantly, lots of debris along with it so they have lots of power behind them. The grow fan you linked is .97 amps, that's a pretty weak motor. If you are worried about noise then put the DC outside, I have two that I use that way, one for my laser and the other for sandcarving. I can hear the air flowing but not so much noise from the DC itself. Plus - when it's outside then you have it drawing the air and you don't have to worry about any leaks, if it's inside pushing the air out then any leaks you have will blow the exhaust back into your room.

[Joe Hillmann]

Here is a thread of someone trying a very similar blower with a very short run and the problems he had.

http://www.sawmillcreek.org/showthread.php?212813-Strong-acrylic-smell-on-small-rastor-and-vector

[Lynn Dixon]

How do you guys have the DC's outside? Are they just sitting on the ground connected to the tubing? If I were to move it outside, I would be limited to only being able to do runs when the weather is nice. Not to mention the fact I imagine my neighbors would get angry about the dust collector being so loud and the hassle of having to carry the DC in and out and connect it everytime I need to run a job.

I have the red dust collector from Harbor Freight and its incredibliy loud. So loud, that I can't carry a converation with my wife 5 feet away without yelling. The noise level is enough to warrant hearing protection, which is another nusiance in its own.

I am having a really hard time trying to find some way of venting this thing and still be able to keep my hearing.

[Joe Pelonio]

Flexible metal is the worst for both noise and venting efficiency. Change to 4" PVC Sewer pipe and you will cut down on the noise from vibration, will have slightly more diameter of flow, and will not catch debris along the inside with the corrugations on the metal. If you are using a dryer vent with door, and there is not enough air flow to open the door fully, you need a more powerful fan. The 400 CFM inline I bought at Harbor Freight was able to handle a 25' distance (PVC pipe) from laser to outside.

[Joe Hillmann]

I think most people here that have blowers mounted outside, have them permanently mounted outside with and on/off switch inside and the blower inside of some type of enclosure.

As far as the neighbors complaining. Do a test. Put the blower outside with it running and walk to the neighbors yard to see just how loud it will be for them. I doubt anyone will complain.

[Lynn Dixon]

Flexible metal is the worst for both noise and venting efficiency. Change to 4" PVC Sewer pipe and you will cut down on the noise from vibration, will have slightly more diameter of flow, and will not catch debris along the inside with the corrugations on the metal. If you are using a dryer vent with door, and there is not enough air flow to open the door fully, you need a more powerful fan. The 400 CFM inline I bought at Harbor Freight was able to handle a 25' distance (PVC pipe) from laser to outside.

Joe, would you mind linking me to the inline fan you bought at Harbor Freight? I'd like to compare it to the ones on Amazon. I am thinking for $70 I am willing to give one a try to see how well it evactuates my laser.

[Dee Gallo]

Welcome to the Creek Lynn!

I vent outside too, using the same system Joe describes. Mine is inside an insulated A-frame to protect it from snow, rain and critters. There is hardly any noise either inside or outside. My pipe is only about 4 feet laser to blower.

[Kev Williams]

First of all, I need to say this: Removing smoke from your laser isn't rocket surgery. ;) ... You just need something to suck the air out. And it doesn't matter if your using $12 a foot super-smooth 6" vent or plain old 3" tin foil dryer vent to move the air thru. Whatever you get will work just fine.

To the best of my knowledge, HF sells only these 3 dust collectors, and I have all 3...

http://www.engraver1.com/erase2/dcs.jpg

I just bought the red one. It has a turbine similar to a turbocharger. I'm using it suck up engraving chips from my IS7000. For tubing I'm using heavy-ribbed black outdoor 4" drain pipe. It moves a lot of air, and does the job. However, if you want quiet, don't get this one. I took the first one I bought back because it vibrated fairly badly, and was LOUD. The replacement was only marginally better. I have it in the well-insulated garage attic, and it's still pretty noisy...

I bought the biggest one about 10 years ago. It, and the medium sized ones are extremely quiet for the work they do. I have 2 medium ones outside in the basement stairwell, one for the LS900, one for the little ULS. I have them connected to switched outlets, with lights connected to the outlets too-- the lights are to tell me they're ON so I don't leave them running all day! With the machines on inside, with just their always-running cooling fans, I can barely hear the dust collectors outside. Just using cheap dryer vent, both exit at ground level into a holly bush next to the stair railing. From 25 feet way, the air escaping is louder than the fans, but not all that loud. At the fence 50' away you can barely hear it. Our hot tub running will drown out the air noise.

The big one I use as a vacuum to suck up the chips from my other engraving machines. Just have a big long ugly dryer vent running along the basement ceiling, with Tee's near the machines, with homemade connections that terminate to 1/2" hoses that connect to the depth gauge vacuums. It doesn't suck like gangbusters, but it does draw enough air to suck up most engraving chips. It's no noisy-er than the medium units. This unit is outside, in an insulated plastic shed, along with my huge, noisy Coleman 175psi air compressor... I can't say enough about this shed, it's right next to our bedroom window (and our neighbors), and you can barely hear the air compressor running. From outside, the sidewalk is about 50' away from the shed, and while you can hear it, you wouldn't notice it if you didn't know it was on...

http://www.engraver1.com/erase2/shed.jpg

Been running these blowers and the compressor for years and years, with not one complaint from the neighbors, even the ones behind us who don't know we're running an engraving shop.

If you want a quiet blower, I recommend the $127 unit from HF. My 2 mediums are 13 and 11 years old, nary a problem. The big one is 10 years old, ditto.

[Lynn Dixon]

Kev,
I have the little red blower from Harbor Freight like you mentioned in your post (for $94.99). It's the one that is super loud. There is no way I can continue to use it as my blower if I keep it in the same room. I literally have to wear ear plugs its so loud. If I intend to keep using this thing, I will have to build some sort of weather tight enclosure and put it outside, since it is a brush motor. My home has a crawlspace, so that might be an option, and just stick it in the crawl space and run a switched outlet to it.

I ended up buying one of the inline blowers from Amazon and I am going to give it a shot.

[Keith Upton]

Hi Lynn,

Short response... put the dust collector outside and replace your flex tube with PVC pipe... more flow and much quieter.

Long response....

That was my thread that Joe linked to back in post #4. I even went so far as to test CFM flows and noise levels for one of the Amazon inline fans and the little red HF unit. The inline types off of amazon are going to be really quite, but are not going to move near enough air... trust me on this one.

At the end of the that thread, I ended up moving the blower outside into a basement window well. I used 3" PVC pipe from laser to duct collector (I had moved on to the red HF unit at this point) and 4" silicone ribbed hose from the DC up and out of the window well (to move the fumes away from the window since it could never be 100% sealed). I ran it like this for a week or so with no complaints from my neighbors (and one is only about 8 feet away with a wooden fence between us). Adding the flex hose on after the DC really cut down on the flow I was getting out of that red HF unit, so this weekend I installed more 3" PVC pipe. Now the DC is up on ground level and a few feet to the side of the window well. I also upgraded to the large green HF dust collector (there was a 20% off sell this weekend at HF) to gain some of the lost flow from all the extra pipe back. The larger unit on the PVC pipe is even quieter than the little red one with just the short section of flex hose. I still have to build a permanent enclosure for this new setup, but for now I just have one of those large plastic storage containers (like a rubber maid) over the top of it to keep it dry. I also wired up a light switch so I would not have to go outside to turn it on or off any longer... so much nicer now!

[Lynn Dixon]

I wanted to post an update. I had ordered one of the Amazon Ventech inline fans, this one to be exact: http://amzn.to/1b7Qp2Q I figured it was worth the money to see what it does, and if it didnt work well, I can send it back (Love Amazon).

I have a window near my desk, so I ended up doing some remodeling. I moved my desk over by the window to reduce the tubing run. I picked up a couple of 6" to 4" reducers and some of the aluminum ducting at Home Depot. I also build a little panel that I put in my window to vent the laser out, and put on of of those dryer vent covers with the flaps to keep bugs and drafts out.
I was lucky enough the the Ventech unit bolted perfectly to the wall dead level with the exhaust fan and almost dead level with the laser. It's below the desk so its out of sight.

I ran my aluminum ducting with a 90 out of the laser, then it slopes slightly down to the Ventech, to connect to a 4" to 6" adapter. Then I have another 6" to 4" reducer out of the fan to 4" ducting that travels maybe a foot to the 90 on my window vent. All in all its about 3 to 4 feet of metal tubing, with 4 feet being the max.

Its actually pretty quiet! My little air comressor for the nozzle is louder that the Ventech unit. It also moves a ton of air. It pulls enough of a vacuum that it sucks the lid closed on my Full Spectrum 5th gen a bit. I can feel a little suction on it when I open the lid, which is great. Full Spectrum did a pretty good job with ventilation, as their logo is laser cut on the front of the unit to act as inake, and it spans almost the entire lenght of the work area of the laser. There is also a "blast shield" behind this logo that helps from creating a huge draft that would move your parts about in the breeze. There is enough air flow from the Ventech unit that it will suck my shirt into the front of the laser's vents

I ran about a 30 minute job using one of the Aztec calenders on a 6" diamter piece of cheap wood I picked up a Hobby Lobby (just for testing the ventilization and lasering quality). I am really pleased with it. I did notice a slight smell of smoke, but my nose tracked it down to a few open screw holes in the fan (Im guessing they are for other mounting positions). So, a little metal duct tape fixed that right up, and there is no more smell.

I will also say this, I noticed when playing with the fan that if I put it on a length of dryer hose that was 8 feet or so, there was a big drop in air movement. The 3 or 4 feet of smooth aluminum ducting I used made a big difference, and there was almost no drop in airflow as compared to the fan "naked". So, I would only recommend these fans if you have a realtively short run of host, and use smooth tubing. Also remember to tape up any of the extra mounting holes on the fan body to eliminate any leakage.

This will work perfectly for me on my FSE 5th gen with my desk right at the window. BONUS: with my desk at the window, I have better light shining on the work area during the day :)

[Keith Upton]

Really glad to hear it is working so far for you Lynn. Did you tape around the control box on your fan? When I was working with the blue fan like yours, there was a fair amount of odor coming from there. Also make sure you seal off the gap between the two window panes created by opening the window.

[Dave Sheldrake]

There is also a "blast shield" behind this logo that helps from creating a huge draft that would move your parts about in the breeze.

It's a legal requirement Lynn, to remain in Class II a laser has to have no direct optical (line of sight) access to the outside otherwise it returns to Class IV.

cheers

Dave

[Lynn Dixon]

AH, Makes sense then. I had just assumed the blast shield was to diffuse the airflow in and about the interior of the work area so as not to blow your work around.

Keith,
That's a good idea, I may tape up the control box as well just to prevent any leakages. I did seal the gap the was created by the window with some weatherstriping.

[Dave Sheldrake]

Remember Lynn, you do need the same amount of air being drawn in as is being pulled out or you end up with a negative pressure container and very little airflow.

cheers

Dave