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View Full Version : Vent to outside suggestions (UK)



Ivan Shuliak
05-09-2016, 2:40 PM
Hi there're a lot of threads like this but most of them are regarding using HF dust collectors which are not available in the UK.
Long story short:

We are going to lease a new unit and want to setup vent to outside and stop using Bofa units.
We have two machines, Fusion 32 and Zing 16 (at the moment).
Landlord let us make the vent hole(s) in the back wall where we plan to put the machines but they want us to supply the drawing and technical specs to attach them to the lease.
That's where the problem comes in.

We never used vent to outside and don't know what we might need. I've seen here some use inline blowers if mounted directly to the back of the machine. Some use dust extractors like green or red HF ones, also inside and outside.
What would you suggest or how would you set it up to get the best result with the least noise? I think we might be allowed to put a box with the extractor outside, but, again will need some drawing (and to be sure, that setup will work for us).

What inline blowers or dust collectors available in the UK would you recommend, also bearing in mind that we might have more machines in future and will need some flexibility.

Thank you!

Tony Lenkic
05-09-2016, 3:04 PM
Ivan,

If you are using Bofa extractor you don't need to vent outside.
Bofa will filter and eliminate odor that you can vent inside working area.

Dave Sheldrake
05-09-2016, 3:23 PM
External venting can come with problems but if you do want to do it try machine mart for their blowers, they are in effect the same as the HF stuff

Gary Hair
05-09-2016, 3:24 PM
I don't know what's available in the UK, but I can tell you that something like the HF dust collectors, installed outside, will give you the best results. Anything indoors will have the possibility of leaking inside your shop area but if it's outside then you have negative pressure on the parts inside your shop and no way to leak exhaust into your shop. Outside would also give you the least noise, short of building a sound-deadening enclosure anyway. In theory, you could hook up an inline blower outside but I don't think you can get enough airflow with them to handle one machine, let alone multiple machines. You could, however, connect multiple dust extractors in series and increase the airflow to whatever you need - maybe multiple inline blowers would work as well. I use two of the green HF for sandcarving and although it doesn't double the airflow, it's significantly more than using one. Also, I have three machines hooked up to one HF blower, each with a gate valve, and there is plenty of airflow even with it being 14 feet above the machines in the ceiling!

Ivan Shuliak
05-09-2016, 4:02 PM
Ivan,

If you are using Bofa extractor you don't need to vent outside.
Bofa will filter and eliminate odor that you can vent inside working area.

Hi Tony, we use Bofa's but we don't really want to spend extra money on filters, which are not cheap, if we can do it with a proper ventilation.
We had to use Bofa's just because there was no other option at old premises

Tony Lenkic
05-09-2016, 4:09 PM
Do you have a wood worker supply house locally? There you would find dust collector blowers that will do the job.
In my area there is a "Busy Bee Machinery" that you can check out for an idea of what will work.
I'm sure there is UK based suppliers you can find.

Ivan Shuliak
05-09-2016, 5:22 PM
Also, I have three machines hooked up to one HF blower, each with a gate valve, and there is plenty of airflow even with it being 14 feet above the machines in the ceiling!
Hi Gary, what is airflow rate of your HF blower? I found 1hp (450 cfm) online here, but not sure if it will be enough for two or more machines. Also what happens if you for example put a blower powerful enough for 3 machines but use only one? Won't it suck a cabinet window in? :)

David Somers
05-09-2016, 5:57 PM
Ivan,

If you can put the blower outside in a covered/protected enclosure for noise reduction and so as not to tie up space needlessly. Or, if it needs to be in your shop you might also put it in an enclosure to reduce noise. Main thing is to have the blower as far towards the end of the hose run as possible so that you are sucking through the hose as far as you possibly can. That eliminates the possibility of leaking back into the garage, at least along that part of the hose run. It will be negative pressure. In my case, I had the option in my house garage to run my hose under the house in the crawl space. I put the blower at the far end right before it exits the wall so the entire length of that run is negative pressure. And since it is under the house it is quiet, even inside the house. I also put a smoke detector down there with it in case of a fire. None of that probably applies in your case though? Anyway.....try to keep the blower as far towards the end of the run as possible to reduce the length of house that is positive pressure. I have a 1 HP 220V chinese monster that came with my laser. It rivals the Boeing Jet Engines made near me for noise.

In terms of "drawings and technical specs" that should be pretty simple. I assume he is concerned with what you run through the wall to the outside and not with the actual blower and hosing? So all you should need is the details on whatever you are going to use for a vent/hood on the outside and the pipe that comes from it into the building. Other than that what is there? I would suggest the vent and protective hood be screened for varmints and insects, and there be a set of louvered covers in the vent that will open when the blower is running and closed when it is not to eliminate as much heat loss in your space as possible. Beyond that what would he want for drawings and technical specs?

Gary Hair
05-09-2016, 7:05 PM
The specs say it is 660 CFM, not sure how accurate that is though... The thing with dust collectors is that they are most efficient, and actually take less power to run, at zero airflow. This means that you can use a gate to restrict the airflow to what you need for your machine and cause any damage.

Dave Stevens-Vegas
05-10-2016, 1:16 AM
Here's what we did...

The machine came with a blower similar to this one http://www.aliexpress.com/item/high-power-900w-Air-blower-exhaust-fan-for-co2-laser-engraving-and-cutting-machine/32533610604.html?spm=2114.40010308.4.2.jXQB15 With 8" hard duct I went up through the ceiling into the attic. Once in the attic I used flexible and vented to the outside to an existing vent. It cost about US$60 for the parts though if you haven't worked with ducting before there might be a slight learning curve.

I plugged the blower into a switched outlet I'd wired when we extended a circuit for the machine and chiller. With that I can turn the blower off (there is no switch on it) and leave the machine, chiller and computer powered.

I've made similar exhaust systems with the Harbor Freight style tube style blower with flex duct in the welding/plasma and powder coating areas.

Kim Vellore
05-10-2016, 2:57 AM
One problem is you will be sucking out the hot air from your shop, that will add up to high heater bills. If you are venting outside I would also recommend looking at ducted air inlet from the outside to your laser. The downside there is if the temperature is below dew point you will have condensation in your laser electronics.

Kim

Ivan Shuliak
05-10-2016, 4:47 AM
One problem is you will be sucking out the hot air from your shop, that will add up to high heater bills. If you are venting outside I would also recommend looking at ducted air inlet from the outside to your laser. The downside there is if the temperature is below dew point you will have condensation in your laser electronics.

Kim
Oh dear... so many points to keep in mind. Did anyone really feel the change in room temperature or noticed higher bills? The room will be about 800 square feet with 2.3m ceilings.
Don't want to risk with the condensation so air intake from outside won't be an option I think.

Jiten Patel
05-10-2016, 7:15 AM
Ivan,

We used to vent outside and unless you have serious heating, it will get very cold in there in the winter. The cost of filters is very high on our Trotec, but something we just build into the cost of sales as working environments for staff and us matter more than a few quid.

David Somers
05-10-2016, 2:08 PM
Ivan,

Those fans do move a fair amount of air so yes, you will notice a chance in temp in the winter. Since my "shop" is my attached two car garage (Roughly 20x20ft with 10 foot ceilings) and the furnace for the house is located there I added a vent onto the main line feeding the house so I have a source of heat out there. The furnace is controlled solely by the house thermostat, not by anything in the garage so having the garage drop in temp doesnt impact my normal heating bill. My temp in the garage will drop to outside temps if I leave the blower running for a long time. A few hours will easily do it mid winter. So I kill the blower when I am not actively cutting/engraving. Otherwise the vent on my main furnace supply to the house can keep the garage 50 or better during the coldest days here. I am in Seattle, WA by the way. Winter day time temps run around 40 to 45 and nighttime runs low to high 30's most of the time.

Michael Hunter
05-10-2016, 3:59 PM
I use an 8" in-line ventilation type blower.

Even on cold winter days, a 3kW fan fire (plus the heat from the laser itself) is enough to maintain the temperature in my 5m square poorly insulated workshop.
At about 45p per hour it's not adding much to my overheads and I don't have to worry about fumes or replacing filters.

Ivan Shuliak
05-11-2016, 5:21 AM
I use an 8" in-line ventilation type blower.

Even on cold winter days, a 3kW fan fire (plus the heat from the laser itself) is enough to maintain the temperature in my 5m square poorly insulated workshop.
At about 45p per hour it's not adding much to my overheads and I don't have to worry about fumes or replacing filters.

Hi Michael, do you use any duct at all or is it attached straight to the machine. I'm just warring about in-line blower efficiency if we put, let's say 8" blower and then a reducer with Y connection as the Fusion have 2 x 4" outlets on the back.

Also, interesting how different it is with a large and small room terms of temperature loses.

Keith Outten
05-11-2016, 5:48 AM
In moderate Winter temperatures exhausting outside will have minimal impact on your shop temperatures and electric consumpton. I have been using an exterior chip box for well over 20 years in Eastern Virginia and extended runs are the normal condition because I use my DC for my laser engraver, CNC router and most of my standard woodworking machines.

David Somers
05-11-2016, 1:39 PM
Keith....am curious. Do you actively heat your garage directly, or are you like me, heating it incidentally off the house feed from the furnace?

I fully admit my approach to heat in the garage is not that sensible. Although the Pacific Northwest has some of the cheapest energy prices in the nation it still irks me to take heated air and actively pump it outside and I base my approach on that rather on some sensible calculation. The only time I actively heat in there is if I am doing something delicate on the wood lathe. I will aim a parabolic heater at me while I work since I am standing still for considerable periods. Otherwise temps of 45 and above out there don't phase me at all. That might change as I get older of course. But for now.....

Jim Finn
05-11-2016, 5:53 PM
I am in west Texas and it does get well below freezing here but cooling is more important because of the 100f weather we often have in the summer. I have my two HP 240volt dust collector outside my shop in an insulated (for sound) closet I built for it. I ran all six inch metal duct and my system works well and is pretty quiet.
I heat my shop with one of those oil filled electric heaters in the winter and the dust collection running does not effect the temperature much in the winter but in the summer my two window units used to cool my shop have to work a lot to keep up with the exhaust of the dust collector. I spend 35 hours a week in my shop so cooling is important to me. Short answer is: Dust collector outside is a good idea for me.

Keith Outten
05-11-2016, 9:54 PM
David,

My shop is located behind my house. I have two separate mini-split heat pumps that provide air conditioning and heat, one for the shop and one for my office on the second floor.

Michael Hunter
05-12-2016, 6:27 PM
I'm just warring about in-line blower efficiency if we put, let's say 8" blower and then a reducer with Y connection as the Fusion have 2 x 4" outlets on the back.

The in-line blower is just fine for my single machine - it gives a good airflow and there's some suction resistance when you go to lift the lid.
It runs with about 3m of flexible hose in total - 2m from machine to fan and 1m out through the window.
(I worry about the flexible hose, but there is a fire extinguisher right next to the machine).

I'm sure that it would NOT be enough for two machines, but since these blowers are quiet and fairly inexpensive I'd just get another blower if I got a second machine.

Bill George
05-12-2016, 6:52 PM
CFM out CFM in. The out takes your Cubic Feet per Minute and pushes it outside. Whatever you take out must be replaced and either heated or cooled your choice. There is something called a heat wheel which will let you recover some of the lost conditioned air. Don't fool yourself the make up air comes from someplace, usually infiltration in cracks around doors and windows. Or if you have a really tight house or building it reverse drafts your water heater or furnace. After a few hours of CO poisoning your body will not care if its warm or cold.

I remember discussing the subject on here a few times in the past.