Ventilation

[loulou3012]

Hi Everyone ,
As a newbie I am becoming conserned about the ventilation i have in the room when I am working . I have read the threads I can find about it but must say I am now confused !
I work an a room the size of a normal garage as we have had it converted and is now part of the house .  I work down the far end with the windows being at the other end where the door used to be . At present I just opan all the windows when I am working which I must say with the windy weather is not idle .
So am I better off getting one of the hydroponic fans or a cooker hood . The problem I have is whichever option I go for do I need the silver tubing to go out the window because if I do  that is going to mean getting the tubing to go from one end of the room to the other ! Or if I get a cooker hood can I just get one that dosent have a tube ? (like the one in my kitchen ) ?
Any advice would be gratefully received .
Many Thanks
Louise 

[Mary]

You do need to get rid of the fumes and let clean air in. Even with the window open, if I forget to switch my fan on I notice the difference.
I don't know whether hydroponics or cooker hood would be better for you, but I do know you need ducting. Recirculating hoods use a carbon filter to take out the grease and smell, but I wouldn't trust it to remove fumes and nasties. Could you move nearer to the window? Long ducting is a lot less effective so you'd need a more powerful fan.
It's all very complicated, but worth getting it right!

[Katiequiggle]

At the moment I have two windows open behind me and the double doors of the shed open and the air whistles around me so I am hoping that the fumes are going out of one of the exits.  I am actively looking for an extractor fan though and as soon as I find a very cheap or free on freecycle its going in.

[dinah46]

I thought opening door and windows in my garage was enough until I took Claire's (Rowanberry) advice and put an incense stick by my torch. Although a fair bit headed for the window a lot of the smoke just hung around so I am now looking into fans and ducting

Diane 

[♥♥Tan♥♥]

To simpify this for you in Corina Tettinger spotlight on silver book the minium extraction rate for a fan should be 300cfm, this is a good ball park number to work with, but whatever you use your ducting needs to be as short as possible otherwise the fan doesnt have the power to suck it right out.

And you need window open for replacement air

[Sal]

I have spent the past week trawling through LE and here looking for advice (literally hours!). It is all incredibly confusing. I have finally ordered a hydroponics fan from ebay. All I can say is decide whether you want to use a hood or more of a funnel type set up with a hydroponics fan and then look for the details of what you need on LE. If you decide to go for hydroponics give me a shout and I'll point you in the direction of the info I found and tell you what I'm planning on doing (not set in stone until I've got my fan and had a play with it!)

[sparrow]

Sal, I'm shouting - could you point to that link, please? 

[Sal]

This is the only real thread I could find about using a funnel rather than a hood on LE (it tells you the size fan you should be using (Dale M, 2nd post)and has pictures of some great looking set-ups):
http://www.lampworketc.com/forums/showthread.php?t=71995

This one is by someone who has set up a pretty cool looking system for their classes. The fan they recommend is smaller than Dale M recommends so I went with the bigger recommended sizes, the set up is quite funky though (I know, I have spent far too much time looking into this ans fans start to be kinda groovy after a while  ):
http://www.southernflames.org/Tips%20and%20Techniques/Tips%20and%20Techniques%20Ventilation.htm

Don't forget it's all American though and the stuff on LE terrified me-I think they are far more paranoid about health and safety stuff and IMHO take things a bit far sometimes-some of what they write seems rather inflammatory and unnecessary (don't get me wrong it's very important to get ventilation right but I think they go too far sometimes).

I hope beadysam doesn't mind me doing this but I found this post by her really useful. Americans state fan powers in terms of cfm's where as we do it by m³/hr and she has written how to convert it in this post:

"Mines actually bigger than that!   I think I went a bit OTT really, but when I did the calculations for my studio size etc I couldn't find a fan that was spot on so I went for bigger and put it on a variable switch so I could alter it depending on what materials I was using.

This is the calculation I used.  I'll type it exactly as I have it in my notebook.  I got this from LE and had it checked by the safety `guru's' over there for accuracy.  Its ages since I did it so please don't ask too many questions - I have a goldfish memory!  Your best bet is the LE safety forums - someone is ALWAYS willing to help with safety issues.

Firstly you see fans rates written as CFM or M3/hour - this is how you work out the conversion.

1 cfm = 1.7 m3 /hr
1 m3/hr = 0.6 cfm


80-125 is the optimum cfm for each cubic foot of coverage of a hood/enclosure. The higher figure is suitable for an `open set up' while the lower is suitable for a more enclosed `Barley Box' style set up.

I was looking at putting in a hood that had an opening of 4' x 2'
So;
4x2 =8
8x80 (min cfm) = 640
640x 1.7 (convert to m3) = 1088m3

I can't remember exactly what my fan speed is but its about double that, so because of the weird shape of my shed I did away with the enclosure and left it open as I had enough fan power to more than cope.  The fan is in an acoustic box so its difficult to get into to check too. I think if I remember rightly, the fan will pull around 1500m3 on its very lowest speed.  We did work it all out at the time but like I say my memory is a bit duff so I can't give you specifics....
Another reason I got my fan is it has a second inlet so I can run another torch if I want too. "

It was in this thread, page 3 if anyone wants to see the original http://www.frit-happens.co.uk/forum/index.php?topic=4852.0

I eventually got (after hours of indecision!) an 8" systemair hydroponics fan which is 950m³/hr (an RVK 200 E2-L1 if anyone is interested!). I am hoping that this will do the trick-I've got a 2nd hand one with speed controller on it just incase it is too powerful (but will mean I could turn it up, hopefully, when I use more nasty things in the future).

Going by Dale M's recommendations in the 1st link you need a fan 350-500cfm which using Sam's calculations works out at 595-850 m³/hr. Going on this basis I think my fan should be strong enough (I hope).

Please check all the sums yourself though (I am pretty sure they are right but I'd hate to be responsible for you hurting yourselves if I've got something wrong). There is loads of other info on LE if you are planning on using a hood instead which I didn't really look at too much as I knew I didn't want to.

Another couple of bits you may want to look at (I haven't really-I was all ventilationed out but they seem to cover a lot of the basics, some again written by Dale M):
http://www.isgb.org/forum/showthread.php?t=10562
http://www.isgb.org/forum/showthread.php?t=10563
http://www.artglassanswers.com/forum/viewtopic.php?t=273

Sorry that was so long, hope it help cut through a little of the c**p I waded through! If you've got any other questions shout again and I'll do my best to help find the answer! Will hopefully have a little more of an idea when my fan arrives and I have a play and decide how to set it up. As I said I'm hardly an expert but there are people out there who really know what they are talking about. You can always ask for help on LE too (I didn't to be honest-they scared me a little!).

Sal xx

[sparrow]

WOW!!!! Thank you - that must have taken you forever to type out! I will treat it with the utmost respect, print it off, and it shall be my bible for ventilation-exploration!!!

[Katiequiggle]

Thanks for that Sal.  So is it ok if I just put an ordinary cooker hood above my work area with a thing going out the wall.  I know that when I am burning the dinner and turn the hood you can see it sucking the smoke out.

[loulou3012]

Thanks for all the info .
I did ring a company on the internet that sold fans and they suggested putting the fan near the window so the ducting wont be that long but I am dubious as to whether that will actually get rid of the fumes where I am working .
If I went for the cooker hood then does that mean that I will have to have one with ducting right along the wall to the window for it to be effective ? Unfortunately I cannot move nearer to the window because of the room set up .
Has anyone got a fan from Ebay as they do seem alot cheaper on there ?
Louise 

[Sal]

I got my fan second hand from ebay-£36 plus £15 p&p for the fan and 10m ducting. Arrived today and we've got it all set up now  Did a little smoke test earlier and it seemed to work but need to do it properly tomorrow with my torch running etc. You need the hood/opening of the fan/ducting as near to you as possible-it's useless otherwise as I understand it - all the fumes will float around and you'll breathe them in before they get extracted from the room. What ever you decide to use fan wise you basically need to have the opening of fan/ducting near to you, then a way of geting the fumes outside. It sounds as though you will need to get a good, strong fan to be powerful enough to extract efficiently over a long distance of ducting. The best option would be for you to move nearer to the window if you possibly can, or to drill a hole through an outside wall to duct to outside. I know this isn't exactly an easy option though.

[Mary]

I know what you mean Louise, I think the fan is more efficient pulling air through the ducting, rather than pushing it along, but neither is great with ducting yards long. You'd need a humungous noisy fan and wide bore smooth ducting (not the collapsible ribbed stuff) to do any good.

Your hood needs to be where you are working, linked to your fan then outside without gaps, not the other side of the room like a bathroom extractor - you are trying to catch the fumes before they reach your breathing space.

[♥♥Tan♥♥]

would it be a good idea for people to list the make and model of their fans so people know what sort of thing to look out for? I always find it especially helpful if someone who has been using a product recommends it.

[beadysam]

I can't get into mine, its in a big acoustic box!