How far from torch does ventilation hood need to be?

princess pink · May 18, 2011, 06:25:22 PM

I bought the tuffnells ventilation at flame off and me and the brother in law are finishing off my shedio on Friday and putting in the ventilation. Wasnt planning on having it directly over torch as have stuff on wall there I want view of. Was just going to have it vaguely near so that it'll suck up fumes but not get in the way.

Also if I'm running the ventilator do I still need to keep the door open?

Blue Box Studio · May 18, 2011, 07:35:30 PM

I haven't the Tuffnell's kit but my torch was about about 15" from the fan and it was getting too hot. I've moved it onto a shelf and that seems better although it still gets hot. I think at FO the end of the hood was only the same from the end of the flame? Martin presumably has don some testing on this so mikght have an answer. As for doors - might be OK this time of year but that's be awful in winter; my shedio's draughty anyway but I have a window open on the first hole of the stay when it's cold and that's enough to keep a throughflow of air. If it's lovely weather then 2 windows and the top of a stable door are open anyway.

Lush! · May 18, 2011, 08:42:39 PM

You really shouldn't need the door open, especially if the end of the pipe is poked through an open window - you do need some way of fresh air entering or you might turn inside out

awrylemming · May 18, 2011, 10:18:26 PM

Quote from: Lush! on May 18, 2011, 08:42:39 PM
You really shouldn't need the door open, especially if the end of the pipe is poked through an open window - you do need some way of fresh air entering or you might turn inside out

Madam Steph · May 18, 2011, 10:28:51 PM

I bought it 3 weeks ago, Princess. I believe it's made to be quite near to the work area, not above.
I keep mine in a box under my table when I'm not torching, and the vent pipe is fed into the kitchen and out the window

Margram · May 19, 2011, 09:46:15 AM

There's loads of ventilation discussion on Lampwork etc - the ideal seems to be an extractor placed in a Barley box. Hot air rises, so unless your fan is incredibly powerful, fumes are going to rise - so it's necessary to place the fan higher than the flame. Check it all out with a joss stick...

princess pink · May 19, 2011, 09:57:27 AM

ok was planning on mounting vent funnel above working area but slightly to the right so it'll be pointing towards the torch at an angle. We are going to mount it to the wall/roof of the shed and put the tubing through the wall in a sealed vent thing so like an extractor fan. does that sound ok?

I will probably have the doors open in this weather but am getting a fly screen as i do not want wasps coming in as i'm petrified of them! probably won't open the door much in the winter and windows don't open. might have to put on a lock thing which keeps door open a crack without it banging and flying open.

Couldn't find specific topics on lampwork etc, but thanks for pointing me there.

Hotglass28 · May 19, 2011, 10:01:54 AM

If it were me. I would place the funnel as close to the end of the flame tip as poss to catch the plume. Putting the funnel to the side is pointless IMO as its not catching the rubbish air, which needs to be taken away asap.

You need a intake of air ideally from behind you so you get a fresh flow of air. And your intake and out of air needs to be spaced apart too. (so you not breathing dirty air)

I work in a room with the hose running all the way down the garden (10ft of hose) with the back doors open and the front door open for a flow of air.

Now, MY setup is to provide me with lots of fresh air cos I need it. Not saying it would suit everyone but I'm very cautious for a reason.

And yes, LE is a great place to research on ventilation issues.

HTH

Madam Steph · May 19, 2011, 12:37:39 PM

Quote from: Margram on May 19, 2011, 09:46:15 AM
There's loads of ventilation discussion on Lampwork etc - the ideal seems to be an extractor placed in a Barley box. Hot air rises, so unless your fan is incredibly powerful, fumes are going to rise - so it's necessary to place the fan higher than the flame. Check it all out with a joss stick...

I have a HH at the moment, with a 13kg propane tank.
Propane is a heavy gas, so I'm guessing that it's ok where mine is till I can upgrade to a better torch and oxycon.
Martin Tuffnell went through it all on the phone with me prior to my purchase, so I think it was good advice.

Hotglass28 · May 19, 2011, 02:14:21 PM

Is propane a heavy gas even when it is used/burnt though? TBH, the only way to see where the plume is going is if you used a heat camera. Anyone got one?

Personally, I don't trust joss sticks, smoke bombs are the way to go.

My third and final setup will be a barley box again, I had no problem with that setup and honestly think its the best way to shift bad air out of the way from your breathing area.

Margram · May 19, 2011, 11:31:49 PM

I found this helpful when I was setting up: http://www.artglassanswers.com/forum/viewtopic.php?f=22&t=150

ARBeads · May 20, 2011, 12:28:07 AM

Here's a link to a Franz newsletter on ventilation http://frantznewsletter.com/?p=1617 may be of use x

Blue Box Studio · May 20, 2011, 07:37:14 AM

Quote from: ARBeads on May 20, 2011, 12:28:07 AM
Here's a link to a Franz newsletter on ventilation http://frantznewsletter.com/?p=1617 may be of use x

The link to the tutorial in this one isn't working.

Now I've moved my fan onto a shelf, with a trunk down to the flame I agree, joss sticks aren't enough. What kind of smoke bombs do you use? Are they the kind you test chimneys with, and where do you get them? I've visions of them burning for ages and my shedio being filled with smoke if the fan's not set up correctly!

Hotglass28 · May 20, 2011, 12:29:28 PM

They only burn for about 15 secs. I was worried about filling the house with smoke too when I used them but I read the intructions first (something I rarely do)

I got mine from a mate who is a plumber but I bet you could get them on ebay. I would send one to you if I could find ANYTHING in this tip that is called a house

utube has a cool vid of a Boro setup using coloured smoke bombs http://www.youtube.com/watch?v=XNs08fYnIqg pretty good semi barley box too.

hth?

Blue Box Studio · May 20, 2011, 01:15:47 PM

Darn, the plumber has just gone - he came to get the hose of my HH and onto my new torch, I could have asked him if he had one I could have. Found some on eBay, £8 for 10 or thereabouts but they burn for 60 seconds. Might try the local plumbing and heating store when I get some more drainpipe for glass storage.