Could someone please fix the typo in the subject line please, should be inline, not inlie. thanks.
Since I've been having issues with my laser for a few weeks, I've had things torn apart. As such,
I've set off the smoke alarm a couple of times on some 10 second tests too. I got this thing about fire, so I REALLY don't like the smoke alarms going off. Even if I know/am the cause and it's under control.
I've been thinking about this for a while and I hit craigslist and found a slightly used 10" activated carbon filter for $20. It's the same kind you can get at any hydroponics store for $250. It came with a polyester pre-filter.
This one is rated at 1800 CFM, has a 10" duct flange, 44" tall, and 13.5" wide, weighs about 30 lbs I'd guess. While I can't hear pellets rattling around (it might use rolled carbon fabric for all I know), I have a local source for 4mm activated carbon pellets that I could drill out the rivets holding the flange on, and just replace the pellets as needed in the future, and no more setting off the smoke alarm. Plus the added bonus of just recirculating the warm air back into the shop.
Well, they don't make a 10" to 4" adapter that's available off the shelf, so I'll have to come up with something. This got me to thinking about inline fans as I know some of you are using them.
I use the little red harbor freight dust collector. It's rated at 900CFM, 1hp (Ha!), 107dB @ 3ft.
I'm guessing it's about 8-9" static pressure if/when I dial in down (on a speed controller).
I'm going to make a Manometer (yes, that's a real thing =), and test things out later on:
http://www.dwyer-inst.com/Products/M...troduction.cfm
If you engrave a ruler on a piece of 18"+ long acrylic, you can read up to 9" static pressure.
Just add some holes on both side of the "U" for zipties to feed thru. Then you can adjust the tubing up/down after you have filled it with water (you can add a drop of red food dye to make it easier to read) so the level of water on both sides are at the ZERO mark, instead of having to pour out a little bit of water till you get it right.
If you know a simple way to read CFM, let me know.
OTHER THAN filling my shop with smoke and timing how long it takes to exhaust that is
From the manual for my machine:
"This system MUST be capable of supplying 250 CFM (cubic feet per minute) @ 6 inches of static pressure (water)."
It then goes on to say:
"In order to meet the laser system’s CFM requirements, a high-pressure, high static pressure rated, exhaust blower must be installed. This type of blower has self-cleaning blades and can maintain airflow even though restrictions are introduced. Length of exhaust pipe, exhaust pipe diameter, number of 90-degree angles, and other restrictions must be calculated when determining the correct exhaust blower unit. Installing an incorrect or undersized blower is not only unsafe, but it can also lead to premature and excessive wear and tear to the laser system.
DO NOT install forward incline, backward incline, in-line, or ventilator fans because these types of air handlers are inadequate and inappropriate for this type of installation."
That last part is a bit of a gotcha ya.... "DO NOT use inline fans"
Also if you look at the specs for inline fans:
http://atmosphere.com/english/html/p...s/vtx/vtx.html
For a 12" inline fan at 388CFM you only have 1.5" static pressure.
(blue line in the graph shown)
That's not even close to the 6" SP requirement.
I'm sure other system have something close to that static pressure as well.
For me, it be easier to mount an inline fan on top of the filter, and find a 10" to 6" reducer (a 10" to 4" doesn't exist for all practical purposes), then run 6" duct to the laser, and then use a 6" to 4" reducer" (which is the recommended way in the manual due to airflow restrictions). I prefer to "blow" (positive pressure) on the longest run, rather than "suck" (negative pressure), but I could totally have that backwards for all I know in regards to performance/efficiency.
I do realize inline fans are quieter and probably why many are using them, but has anyone tested the SP (static pressure) or CFM on their system including any/all the duct work (end to end)?
For those using inline fans, have you had any issues?