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Safety -- Make sure you are safe!

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  #1  
Old 2005-06-11, 1:11pm
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Does a range hood provide good enough ventilation for a Pirhana torch? That probably depends on the room size and the source of intake air... I have a pretty big workspace, about 10 feet by 20 feet, in the basement. But that will change - we're going to remodel and I'll have a smaller work area (which suits me fine). Any advice/info is appreciated.
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  #2  
Old 2005-06-11, 2:58pm
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It will depend on what the TRUE cfm (cubic feet per minute) of the fan is.

Generally speaking, you are going to want a minimum of about 300 CFM of air movement.

Be sure to use smooth sided duct work, and provide a fresh air source.
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Old 2005-06-11, 11:46pm
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Thanks, Mike!
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Old 2005-06-14, 3:57pm
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I thought posting this image Dale M. so wonderfully made here in Ventilation would be great...its VERY VERY good
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  #5  
Old 2005-06-14, 6:48pm
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Edit to nothing.

Dale

Last edited by Dale M.; 2005-06-16 at 7:31pm.
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  #6  
Old 2005-06-15, 6:04am
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I'm running over 400 CFM on a fan that is 2' behind my torch, DIRECTLY exhausting outdoors and it is NOT ENOUGH. I occasionaly can smell "torch byproducts" while making a bead.

Unfortunately, lampworking torches don't squirt out fumes like a water hose squirts water. Because of the rapid expansion of these fumes into the air, you must move way more air than you think, or contain the byproducts in something called a fume hood.

And I agree with Dale, I don't believe there is a "range hood" on the market that will move enough air to make it safe. And, when you add ducting to the hood to get the fumes outdoors, you cut the air movement down drastically. Thats why you have to "supersize" the air flow in the first place.
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Old 2005-06-15, 6:24am
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Hoods are funky things. The wrong design or layout and you don't get full removal of all the fumes and by-products.

There are a couple of issues that you need to take into account when designing a ventilation system - yes, DESIGNING. You cannot take an off-the-shelf kitchen vent hood and expect that it will remove all the 'bad stuff'.

1. You need a certain CFM (cubic feet per minute) of air removal (and replacement by incoming make up air), based on the size of the hood.

and

2. You need a certain flow rate, or velocity of air movement.

Then, you need to take into account the "plumbing" issues - diameter of ducting, length of said ducting, number of bends etc.

In this document I wrote for the Art Glass Forum http://www.artglassforum.com/forums/...ead.php?t=1357 , called Ventilation 101, I discuss all the variables, and show several examples of how to design your own system. I tried as much as possible to write it in everyday English, and tried to keep the amount of jargon to a minimum.

You will need a calculator, and pencil and paper, but the time you spend doing the design work will be worth it in the long run. A properly designed ventilation system will save your health, and without your health, you have nothing.

Last edited by MikeAurelius; 2005-06-16 at 6:12am. Reason: oops: movement instead of minute
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  #8  
Old 2005-06-16, 4:03am
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Oki I have a question for you guys..
CFM = cubic feet per movement
How long is a movement? A minute? An hour? ....

I'm asking this, cause when I get the money, I want to move my little studio into a little garden shed type building and the measurements for things like that are different here in Holland. It will cost me more than I care to spend on anything other than this, to get the shed (wooden shed), insulate it, ventilate it, floor it and decorate it.


Hugs,
Sarah
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Last edited by Jacinthe; 2005-06-16 at 4:05am.
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  #9  
Old 2005-06-16, 4:19am
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Sarah,

Its actually Cubic Feet per Minute. It is a very standard measure of air movement, obviously the VOLUME of air that can be moved in a given amount of time.

If you can eliminate any duct work between the fan and the wall of your new shed, then that is a good thing. People just don't realize that adding duct work (round, square, rough, smooth, etc) REDUCES the fans CFM significantly. This is called "duct losses".

It can easily reduce the flow to HALF or less with just a few feet length of the wrong duct. This is why you want lots of extra capacity in the fan, to make up for duct losses.

Bill
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  #10  
Old 2005-06-16, 12:44pm
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Most kitchen range exhaust systems are not adequate for lampwork.

I did some homework and I finally settled on a 700 CFM exhaust fan that I got from Granger for $240. Granger is wholesale only, but if you have a resale number they will do business with you. The ducts and the louvers were extra, but the whole thing, with installation was under $600. I can burn incense right in front of the torch, and as long as I have the exhaust fan going, I can't smell it across the room.

Please consider getting adequate ventilation for your studio. The torch produces carbon monoxide and nitrous oxide gases that are toxic, you don't want to be breathing these fumes. I have asthma, and I can tell you that working with just the window open before I installed the exhaust fan would cause breathing difficulties for me. Now that I have installed the exhaust fan I don't have any lampworking related breathing problems. Your health is more important than making beads.
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  #11  
Old 2005-06-23, 7:38pm
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I'll be doing my torching in a 1000 sq ft area (my basement). I'm going to be working with a hothead and will have a fan for air circulation. Will I need a vent hood or will I be ok with such a large room to work in?

Thank you,
Heather
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  #12  
Old 2005-06-23, 7:49pm
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Quote:
Originally Posted by SquareOneBeads
I'll be doing my torching in a 1000 sq ft area (my basement). I'm going to be working with a hothead and will have a fan for air circulation. Will I need a vent hood or will I be ok with such a large room to work in?

Thank you,
Heather
Simply.... No.... Just circulation it around room will just cause to eventually build up to a point where you are in danger.... The only protection is by evacuation of contaminated air from room and replacing it with fresh air. There is on other solution than positive venting contaminated air outside, which ususally indicates you need a hood with fan of some sort and a source of makeup air. Window or door open to outside.

Dale
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  #13  
Old 2005-06-24, 1:15am
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Here are a couple more ventilation resource links:

Glasscraft, Inc. makes a really nice vent hood that pulls @ 650 cfm:

http://www.glasscraftinc.com/produc...fm?part_id=1342

For even more cfm, you can add an in-line booster fan in your duct work or where your duct work leaves your space, or both. This will also help a regular kitchen range-hood move way more cfm. Here's an example:

http://www.grainger.com/Grainger/pr...1631324&ccitem=

Grainger has tons of other ventilation equipment, including squirrel-cage blowers, that will move a substantial amount of air. Here is one example:

http://www.grainger.com/Grainger/pro...756008&ccitem=

The one drawback of Grainger (as Alex mentioned) is that they are wholesale only. If you cannot order from them, Home Depot and Lowe's carry many similar products.

You can also get your local heating/cooling (HVAC) company to set you up with a ventilation system, often for much less $ than you might expect. Just make sure that you explain to them that the ducting must be straight-sided, have as few elbows as possible, be as short as possible, must vent to the outside, and must move whatever cfm you determine to be safe in your particular studio arrangement. Showing them Dale's diagram will help them out a lot to figure out what you are talking about.
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  #14  
Old 2005-07-08, 9:49am
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jsut a grainger note: I ordered the 10" wall vent from them to go thru the wall of the house to the outside. I don't have resale, but I just had them deliver it to the local Ace Hardware, and "bought" it there. Easy peasy.
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  #15  
Old 2005-07-08, 11:54am
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Quote:
Originally Posted by IF-Designs
I thought posting this image Dale M. so wonderfully made here in Ventilation would be great...its VERY VERY good
There is an issue of ventilation that does not seem to have been addressed yet.

If you have make-up air coming from behind you, there can be a significant "dead spot" or eddy in the air directly in front of you. Think of a boulder (you) in a river (airflow) and the eddies behind it. Currents can actually be going upstream (towards your face), as any river kayaker can tell you.

This is more likely to be the case with box fan/window exhaust systems than overhead systems, but airflow patterns should be checked with the torch on and someone sitting in normal working position in front of it. Check the air movement between you and the torch.
I have addressed this problem with a small fan in dryer duct introducing fresh air crosswise between me and my torch.

-Don-
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Old 2005-07-10, 12:37am
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Quote:
Originally Posted by lunesse
jsut a grainger note: I ordered the 10" wall vent from them to go thru the wall of the house to the outside. I don't have resale, but I just had them deliver it to the local Ace Hardware, and "bought" it there. Easy peasy.

Good thinkin', Lincoln!!!

Tips for ordering from Grainger if you cannot set up a wholesale account:

If you know any general contractors, they can order all of this stuff for you.

Know anybody that works on houses at all? They can probably do it, too.

Or, call a local HVAC company, tell them the part #'s you want them to order, and see if they can get them for you. They might charge you a nominal fee, but it will be worth it. If you don't know how to install all of this stuff, they can do that for you, too. These guys are used to dealing with contractors, which are usually pretty serious get-it-done-on-time kinda guys. If you explain to them that you are just a homeowner trying to do something kind-of weird, it might peak their curiosity and you might be able to work out a deal with them. Tell them your time schedule is somewhat flexible, and they will be happy to make it work within their schedule, usually.
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  #17  
Old 2010-04-29, 5:13pm
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Default lampworking ventilation in basements Q&A

im in an "L" shaped basement about 825+ SqF. The basement is big and open and has 3 windows in it. I will be using the Nortel RedMax torch and am wondering if this air purifier will do the trick in properly ventilating my workspace and basement?

* link to air purifier *

http://www.air-purifiers-usa.biz/air...irpurifier.php

Last edited by Meta Glass; 2010-04-30 at 3:32pm.
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  #18  
Old 2010-04-29, 5:17pm
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Quote:
Originally Posted by Dale M. View Post
Simply.... No.... Just circulation it around room will just cause to eventually build up to a point where you are in danger.... The only protection is by evacuation of contaminated air from room and replacing it with fresh air. There is on other solution than positive venting contaminated air outside, which ususally indicates you need a hood with fan of some sort and a source of makeup air. Window or door open to outside.

Dale
what about air purifiers?
will they be sufficient enough for a basement?
like this one
http://www.air-purifiers-usa.biz/air...irpurifier.php
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Old 2010-04-29, 5:20pm
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Quote:
Originally Posted by IF-Designs View Post
I thought posting this image Dale M. so wonderfully made here in Ventilation would be great...its VERY VERY good
where can i get the proper ventilation system like this?
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  #20  
Old 2010-04-29, 5:47pm
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As far as I know you cannot buy a complete system. It would be too costly and systems are made to fit your workspace and workspaces vary alot.

Most people build the workspace and then figure out the CFMs needed according to the opening of the front of the hood they are planning to build, and then they buy the appropiate exhaust fan, ducting etc.

Or you can do the ducting to be on the bench almost to grab the fumes and not use a boxed working area. Like this one at Andrea's studio.

http://www.andreaguarino.com/ventilation/

Basement ventilation systems come with a completely different set of issues that have to be addressed. Type in basement studio in the search box and you will have lots of information.

Lorraine
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  #21  
Old 2010-04-29, 7:23pm
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Quote:
Originally Posted by Meta Glass View Post
what about air purifiers?
will they be sufficient enough for a basement?
like this one
http://www.air-purifiers-usa.biz/air...irpurifier.php
NO....... Air purifiers are not designed to remove the toxic components of combustion like Nitrous oxides and carbon monoxides....

You may want to read this paper on basement ventilation...

http://www.artglassanswers.com/forum...php?f=12&t=430

Dale
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Last edited by Dale M.; 2010-04-29 at 7:26pm.
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  #22  
Old 2010-04-29, 8:50pm
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Dale,

Here is layout of my basement... roughly 825 sq ft.

my basement is not dark dingy nor is it cluttered and dirty... Air circulates pretty fluidly throughout the basement. Im just curious what you would recommend for an area like this. There are so many different ventilation systems i want to be sure my is adequately doing it's job.

Would you recommend an overhead duct that leads straight out the window in front of my work station?

* or *

would something like this work + the added flow of massive fans at each window?
http://www.andreaguarino.com/ventilation/

thanks for the quick reply!

Kelso, Denver
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Last edited by Meta Glass; 2010-04-29 at 9:28pm.
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  #23  
Old 2010-04-29, 9:40pm
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The fans at each window are for students. The CFM is the same for each fan unit in front of a students torch.

Unless you are going to teach or want friends over to torch you would only need one of these.
Lorraine
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  #24  
Old 2010-04-29, 10:52pm
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Quote:
Originally Posted by Lorraine Chandler View Post
The fans at each window are for students. The CFM is the same for each fan unit in front of a students torch.

Unless you are going to teach or want friends over to torch you would only need one of these.
Lorraine
will using one these fans you posted sufficiently keep my basement clear? I understand it will suck out the bulk but what about any remainders? do you think running one of these fans you posted - http://www.andreaguarino.com/ventilation/ - AND having regular large fans at each make up air entry point will be enough ?

thanks
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Old 2010-04-30, 6:59am
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If you are running a single vent with proper fan (hood), and if you have a decent make up air source there should NOT be any remainders.......

THE whole basement becomes essentially one very large duct and air should flow freely through the total space... Only caveat here is items like gas furnace, gas water heater, gas clothes dryer and maybe floor drains.... The furnace ( older not closed loop vent) and water heater produce same gasses as your torch, carbon monoxide and nitric oxide.... If these units do not have a enclosure and their own air source independent of studio, you can get a condition called a FLUE REVERSAL where the glass studio ventilation pulls the toxic gasses out of water heater and furnace flues and spreads it around your studio just the same as the "make up air" and contaminates make up air with the same gasses you are trying to prevent filling studio....

Remember nature abhors a vacuum and will push air in any place it can to reduce vacuum. Putting a fan in a window or having proper hood and fan for glass bench creates a vacuum , nature pushes in make up air through any open window or door AND FLUES for gas appliances..... This is why a basement is harder to get proper ventilation in, also applies to spaces like garages that have gas appliances in them and are rather "sealed" with doors and windows are closed.....

Its not the size of the basement, or how well its decorated or not, it is WHAT is in basement, your torch, gas water heater, gas furnace, gas clothes dryer, floor drains that have to be dealt with.....

Any good fan that has CFM rating in proportion to you glass work hood or fume cabinet will work.....Does not matter what room size is or how its decorated, it does not really matter how duct work runs (as long as its not restrictive) its all about air flow and how replacement air enters "space"....

By the way really good sketch..... But how big is your hood/fume cabinet on glass bench?

Dale
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Old 2010-04-30, 9:27am
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Thank-you Dale...Whew!

You see what Dale is saying about a basement having it's own set of safety issues? They are so very important to deal with and get them resolved. I am so glad you are really trying to get it done right the first time.

Lorraine
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Old 2010-04-30, 9:13pm
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Quote:
Originally Posted by Lorraine Chandler View Post
Thank-you Dale...Whew!

You see what Dale is saying about a basement having it's own set of safety issues? They are so very important to deal with and get them resolved. I am so glad you are really trying to get it done right the first time.

Lorraine
thanks for the kudos...
so the plans have changed, and making a basement is now out of the question... too much work and risk and I dont like the paranoid feeling I would get being down there with all this... i am now trying to move in to my 10'-10' shed out back or in a corner of my garage...
really hoping i can move some shit around and get into the shed. more practical work environment and ventilating wont be AS much an issue. Either way the basement is out.

I am very excited to get underway, and finally start playing with fire!!!
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Old 2010-04-30, 9:22pm
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EXCELLENT CHOICE!!!!

Lorraine
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  #29  
Old 2011-09-06, 7:12pm
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I have an approximately 80 sq ft shed that is near being complete in my back yard. It is far from air tight in that the door and 2 of the 4 ceiling/wall corners (in the front and back of the shed due to the way the roof's boards rest) have gaps and such. I have a 1600 cfm fan: http://www.gaf.com/Roofing/Residenti...able-Vent.aspx

If the fan is between 3 to 4 feet to the left of my torch attached to/through the wall, venting directly to the outside so that there is no reduction in cfm from duct etc, would this be enough ventilation so that I would not require to put something over the top area of my bench?

I was thinking the 1600cfm fan would create quite the vacume, and as a result air would be sucked in through all the open crevices of the door and 2 roof/wall corners to replace the air leaving. I could always open the door which would be directly behind me, but I would wonder if this is even neccesary.

Would it be correct that the fans true cfm would only match the air flow that is able to come in through these spaces? My main concern is that I live in a city, and lets face it... there are tons of junkies and tweakers who would love to steal a whole glass shops worth of equipment. I don't want people walking by to become curious and draw unwanted potentially sketchy attention to the shop (I put way too much love, energy and money into it to have someone steal everything) as you can see into the backyard via the gap between neighboring houses when walking by on the sidewalk out front.

So I would prefer not to have my door wide open for air replacement if I can help it, nor do I really want to have to install a second fan for intake in a location less visible. I was kind of hoping the brute power of 1600 cfm would work out since id be sucking in air from outside anyways due to the vacume.

There is a window I plan to set up in front of, but the shed was old and the window does not move, it was installed in a way that makes it for looking through only. If I had it my way I would remove the window and set my fan directly in front of my torch and use the side area where I am putting it now as my intake "window". However I am renting the house I am at and the landlord was kind enough to provide and help me put up the shed for my studio (he didn't want anything going into the basement which I thought was perfect because it had a dirt floor and cement foundation up to my waist/chest, but oh well) and when I asked to remove the window so I could use it for venting he didn't seem to go along with the idea.

He actually thought the spaces along the roof and walls would be enough until I stressed I needed to put up a fan somewhere which was resolved with the corner of the wall to my left (and left of the planned bench).

Another option for the bench is to set it up facing the corner so that the torch is really almost nearly pointing directly at the fan anyway. Sorry to rant, I guess my main concerns are if I really need to worry about an intake with the amount of air that I hope the 1600cfm will move for me anyway, and if I do indeed make a "window" section open up for intake, if I really need a hood to trap gas with when considering the 1600cfm and 80sq ft space I will be working in.


edit: after some thought, I figure the hood should go up regardless, as it never hurts to be extra sure and it requires very little effort for me to box in the workbench anyway. So the question is more do I still need a door or window open or should the gaps be good enough?

Last edited by caogomi; 2011-09-07 at 12:11am.
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Old 2011-09-07, 9:45am
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cheng076 cheng076 is offline
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You are almost correct. The fan, no matter what its rating will only move as much air as will go out an opening or will come in an opening. However, a lot of factors enter into this; fan power, air speed, tolerable air noise, turbulence that moves the flame around, etc. All these factors and others balance to form the vent system. Idealy the air opening comming in should be equal to or larger than the exhaust opening. The fan should be powerful enough to move that air at a speed that is fast enough to keep your head and shoulder area free from contaminants but not so fast that the torch flame is moved around too much nor causes too much noise. That will depend on duct or opening size.

As for privacy a screen door would provide a visual barrier that would preclude looking inside when it was/is lighter outside than inside. A louver setup might work well also. Something like those old fashioned venetian blinds.

Also the air flow should be from behind you so the air flows around your head and shoulders and parallel to the flame so the option of having the fan in front of you is the best option. The hood would mitigate that as it would tend to collect the contaminants from directly in front of you and forcing the air to flow from behinnd you then the exhaust direction out of the hood is less inportant.

last comment re the 'gaps'. As montioned with a hood in place and the work area 'boxed' in the air flow is set by the opening in the 'box' so the gaps will more than likely be adequate.

just some free thought from your discription of the setup. Hope it helps.

Last edited by cheng076; 2011-09-07 at 9:48am.
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