Exhaust vs Dust Collector question

[William Vanderlaan]

So we're taking delivery of our Trotec Speedy 400 in February and we couldn't be more thrilled with the process! I'm a little confused on exhaust options though. We will be cutting and engraving mostly wood, with some acrylic work. The laser we currently use has an inline exhaust fan venting outside, is this the type of setup I should use for the Trotec? Or should I buy a dust collector (this is the one that was recommended to me: http://www.atlas-machinery.com/1-1-2...with-canister/) and exhaust into the bags? Any help would be much appreciated, we're in the country with no neighbours so exhausting outside is not going to be an issue. I'd like to keep the noise to a minimum in the shop. Thanks in advance!

[Rich Harman]

Do not exhaust into bags! You need to get the smoke and fumes outside. Dust collectors are recommended because they move a lot of air - but instead of exhausting into bags or other filters, you route them outside. Best case is to put the blower outside in a weatherproof enclosure. The reason is that it will be pulling air through all the indoor ducting. If there is a leak it will be pulling air into into.

[Tim Moy]

Would definitely use your current system straight outside. Emptying the bags and cleaning filters is extra work you don't need to do.

[Keith Downing]

A traditional dust collector is never really an option.

Are you perhaps confusing a fume extractor with a dust collector? Many people with the high end US lasers pony up the couple thousand dollars for fume extractors so that they can use their machines indoors with minimal odor. Or, you can simply use an inline fan or blower to vent your exhaust directly outside if that is possible in your case.

[Rich Harman]

A traditional dust collector is never really an option.

??? Many of us use a traditional dust collector - vented outdoors.

[Jerome Stanek]

??? Many of us use a traditional dust collector - vented outdoors.

But you take the filter off either bag or hard filter so you are turning into a fume extractor sa you are not collecting anything

[Keith Downing]

??? Many of us use a traditional dust collector - vented outdoors.

You use the motor/blower from the dust collector, and vent the exhaust directly outside. You DON'T use the dust collector as it was traditionally intended: with a bag "collecting the dust". Take a look at the dust collector he linked; I think you'll agree he misunderstood the goal. LOL

[Rich Harman]

This is a ridiculous thing to argue about. Many people use the cheaper Harbor Freight Dust Collector simply by attaching a hose instead of the bag. If you then want to call it a "fume extractor" then fine, but the thing a person needs to go out and buy is a "dust collector". They don't need to go searching for a fume extractor which Keith describes as costing thousands of dollars.

Are you perhaps confusing a fume extractor with a dust collector? Many people with the high end US lasers pony up the couple thousand dollars for fume extractors...

[Keith Downing]

This is a ridiculous thing to argue about. Many people use the cheaper Harbor Freight Dust Collector simply by attaching a hose instead of the bag. If you then want to call it a "fume extractor" then fine, but the thing a person needs to go out and buy is a "dust collector". They don't need to go searching for a fume extractor which Keith describes as costing thousands of dollars.

Now we're going in circles, but to be clear: I was assuming someone at Trotec had possibly mentioned a fume extractor exhaust system as an add on (they sell 5 or 6 different types of these and all are well over $1,000 last time I checked). And that he was possibly confused thinking a dust collector (with the bags in use) did the same thing as a fume extractor (which uses filters to clean the air).

Certainly many dust collectors can be used to vent exhaust outside by connecting a hose. But there wouldn't be any reason he would want a large double bag version like he linked to.

But we all agree: a motor/blower with a hose venting outside will be sufficient for his needs regardless of whether the motor was originally sold as part of a "dust collector". LOL

[William Vanderlaan]

Thanks everyone, and sorry for the confusion (I would have responded earlier but was away for a week)! I've done away with the bags, and will strictly be using the blower hard-piped to the laser with flex-pipe on both ends of the blower, exhausted outside. A couple more questions.
1. There will be about 12' of duct from the Speedy400 to the blower, and then another 6' from the blower to outside. Should I stick with 4" duct off the Speedy400 to the blower, and then carry on with 6" outside, or should I step up to 6" duct right off the Speedy400 all the way outside? I will probably have 2-3 90 degree elbows in the total run.

My next concern is replacement air in my shop. We're located in Ontario and I'm slightly concerned that I will be exhausting all the warm air in my shop every time I turn this thing on. Does anyone have any experience with this? It's radiant heat throughout. Could I get away with a larger electric heater to compensate, or am I looking at getting a HRV installed? Any input would be appreciated, especially if you've run into this issue. Cheers!

[John Lifer]

If there will be 12 feet to the blower, I'd change to a hard pipe for as much as possible. If the speedy has 4" I'd just stick to 4" way cheaper and better options with 4" I'd get two or three sections of 3' metal vent and use flex to connect on either end if you have compound curves. If not, use metal elbows. You lose a LOT of flow with flex hose. Just my opinion. I end up opening a window a crack if I'm exhausting a lot. Basement is already cold. There are some heat exchangers but I'm not sure how much they really help.

[John Lifer]

You know, I wonder if it would be possible to bring in a external air duct and duct it into one of these Trotec or Epilog machines. They seem to be fairly air 'tight' at least way more than my Chinese machine that has holes all over the panels. Would be kind of interesting to have an incoming duct that you open when you turn on your blower. I'd bet you could do it and reduce your heat loss.....

[Kev Williams]

Actually, that sounds like a good idea, but... Yesterday my BIL was Cermarking cowbells in the Triumph. There's very little smoke produced, and even with the blower running the smoke from the Cermark just drifts upward and out of the cabinet. So I've always assumed that while the blower gets some of the smoke, the remainder that leaves the cabinet just dissipates into the room.

Normally the blower is on, but I've Cermarked bells many times before without running the blower when there's only a few bells. But this is an order for 250 bells, so normally the blower would be on. Since moving the one blower outside last week, the shop light that normally acts as the blower "on" light (same powerstrip) I've plugged into a wall plug, so it's just on. So the BIL thought the blower was on since the light was on. But it wasn't...

About an hour in, and even with the front door wide open (winter? what winter?), the smoke alarm went off!

I went upstairs and I found the garage filled with a light cloud of Cermark smoke. It built up so slow the BIL didn't notice...

So the fix was to open both lasers and fire up both blowers, which cleared the room of smoke pretty quickly. Both of these events surprised me, that there was THAT much smoke in the first place, and how fast it seemed to clear out once the blowers were running...

With that in mind, I'm not sure I'd want a blower to extract air only from outdoors. While it does suck that warm air is blown outdoors in the pursuit of smoke extraction (and $$ ), I can say from yesterday's escapades that room ventilation is definitely necessary

[Rich Harman]

...There's very little smoke produced, and even with the blower running the smoke from the Cermark just drifts upward and out of the cabinet.

I have not had that problem, maybe because the total ducting distance is less than five feet or maybe because I have taped up many of the leak points on my machine. Smoke can rise up and collect near the lid, but not for long as it has no path to get out against the air that is coming in around the gaps in the lid.

As the machine was supplied there were many gaps that allowed fresh air to come into the machine that reduced it's smoke evacuating efficiency. After taping them all up (2" gaffer's tape) it got much better, and the compartment that my tube is in, and the tube itself now remain clean even after hours of cutting MDF. There is still room for improvement but it works well enough now that I am not motivated to make it any better.

[Ron Sleeman]

Hello William: I just got back from holidays. I see you where asking about the dust collector. I have a 3 hp in my shop & my machine is 20 feet from my dust collector. I have no problem moving smoke or anything else...lol I changed the outside venting, as I have a new neighbour living next door with a new born baby..lol So I made a box outside with insulation in it. It is built like a maze inside with the insulation in it.IMG_4604.JPGIMG_4603.JPG