Ventilation problem
 

Hello from Prague, I am new to lampworking but I have been reading here for quite a long time. I would like to thank everyone for the precious info and help that you provide and I wonder if you have any opinion about my ventilation problem. I set up a small home studio in a spare room on the first and floor of my house. Regarding the ventilation I got inspired here:

http://www.andreaguarino.com/VENTILATION.html
http://www.aspenhotglass.com/ventilation.html
I´ve purchased a max. 705 m3/hour= 412 CFM fan /German Ruck Ventilatoren/, an aluminium "6" flex tubing 2 metres long, and a "6" to "10" metal adapter at the end. The adapter is about 30 cm from my GTT Cricket torch, facing it. Because of the fan and the open window behind me, that should bring the fresh air in, the room is a sort of windy. I did the test with a "smoking" stick and everything seemed to be ok, the smoke goes from the torch to the entrance of the tubing /round "10"/ only.

The problem is that after about 2-3 hours of work I clearly start feeling sick. Bitterness in my mouth, a sore throat, a sort of alergic reaction in my nose...and it lasts for a couple of days!!! Having followed the rules that seem to be ok even for some professional studios I can´t figure out where is my problem and what I do wrong... Is it possible that I am super sensitive? Did anyone have a similar problem? Thanks a lot for any suggestion, Miscia

I'd like to help you, but I'm sure the usual suspects will come around soon and tell me they think I'm wrong...even though my last job was modelling hydraulic flow of gas. So I'd rather not say anything. There's a lot to look into that isn't listed here, so it will require some discussion.

The clean air supply and the exhaust must also be separated. That could be different in various parts of the world. Generally 3 meters if within your local buildings codes regulations. More is often better!

Many folks use 750 CFM fans with duct work that is 25 cm to 30 cm in OD. IMO 15 cm is too small.

Maybe your fan is to "strong" and leads to a negative pressure near to your torch. This makes the fumes coming to your face before they are sucked off.

I have had that issues too and skimmed the whole LE threads about ventilation.
There are some very good explanations on how the set up should be to prevent this.
If I can find the threads I will post the links in here later.

What brings a lot of easing was building a Barley box.

Thanks to everyone for your time, I feel quite desperate... the only thing I am sure about is the clean air supply as it comes from a different side of the house... I go to study the Barley box now, have a nice day

Welcome to LE.

LE has a wonderful search tool that is at the top of your screen. On my monitor, the background is red. Look at the line that says "UserCP FAQ Members List/RAOGK... to the far right is "Search." Just click on Search and a drop down box will appear for you to type the topic in that you want to search. For example, "ventillation" and then LE will search for any threads that have the word ventillation in it. For words with 4 or less letters, you have to use the * as a wild card. For example: red*

This can really help because it will bring up threads that may have already discussed your exact problem and the answer may already be here somewhere.

EDITED TO ADD: This is just one thread that I found. I haven't read all the way through but it's a start... perhaps something here will lead you to an answer.

http://lampworketc.com/forums/showth...t=ventillation

Best of luck,

Sue

Thank you Sue. I always wondered where that search field was. LOL!

Copied from this site, not my words, but maybe this is the issue. Also pasted the link to the site, seems to have some good information.

“A source of fresh air to replace the exhausted air.” Replacement fresh air is often overlooked by the do-it-yourselfer. The rule of thumb for replacement air is to provide fresh air at the same rate that combustion air is being exhausted. This means that if you are exhausting 400 CFM (cubic feet per minute) of combustion contaminated air, you also have to provide incoming fresh air at the rate of 400 CFM.

http://mikeaurelius.wordpress.com/20...basics-part-1/

Can you post a photo of your setup? I'm a bit confused about where you're venting.

Post a picture
 

Yes a picture might be helpful.

The most important thing is to ideally suck the "used" air away from the torch.

Please have a look at the pictures of our German Bead Maker Forums (http://www.perlenwiki.de/index.php/L%C3%BCftung). Or here at my fb account:
https://www.facebook.com/Glasperlenw...tImGlockenbach

For fresh air it usually is sufficient that you don't open the window etc. next to the exhaust.

One thing that you always should not forget (all people in my classes learn it). Don't forget to drink, because the air is dry and you are working very concentrated, you might forget to swallow (some even forget to breath). :badgrin:

Cheers,
PerlenFlo

Thanks everyone for advice. I´ve obviously read the LE threads about ventilation using the "Search" O:) and among various suggestion I have choosen this one, which seemed pretty simple and working for some of you...it didn´t work for me, that´s why I´m asking... here is the picture...

Thanks for the suggestion about drinking and breathing - it is true, one is so concentrated...and it may also be my case

My troubles are definitely not caused by lack of fresh air as I have a window on the opposite side of the room, serveral metres from the exhaust...

Your Picture
 

Hi Miscia

I had a look at your picture.

The setup is not ideal, but it should not cause any issues.

My main question is: Why do you use that funnel?

You might have seen the pictures of my installation. The end of the tube should suck the "used" air but if possible not much more of unused air. This means you should try to find the best set up for that.

Before installing I used my hands to identify the stream of hot air. Hot means it's coming from the torch and contains all the gases you want to get rid of. In my case I built a circle with my hands around the flame where it comes from the torch surface. I move the hands along the flame always making sure it would not be too hot for my hands.

This way I found that the hot part past the flame is slightly going up. Next step I installed one of those flex tubes with the opening to the torch. I made it a bit lower than the hot airstream was that I detected.

I try to show a picture in my gallery (setup of exhaust tube in relation to the torch / flame), hope it works.

If the ending is bigger then the hot airstream it will suck "fresh" air which is unnecessary and perhaps more noisy and windy. And colder in winter.

If you can't see the image, please visit my FB account
https://www.facebook.com/Glasperlenw...tImGlockenbach

PerlenFlo
from Munich which is close to Prague, compaired to most of the other users,

Hi PerlenFlo, right, compare to others you´are round the corner...

...thanks for your advice, had a look at your FB pictures, seems that your tube finishes a bit above the torches...will give it a try...

One more question: what diamenter have your tube...15/16 or 20cm and in your experience my fan RUCK 160L CFM cca 400 should be enough for this type of set up? Thanks for yr help, Miscia

Hi Miscia,


Just the size of the fan tells me that it must be enough for one tube / torch only.

My flextubes do have 16 cm, but I'm sure 15 or 20 would be fine as well. Yes it finishes above, since hot air goes there. Without a fan it would make a curve and go up vertical. But the suction get's it straight in the direction of my tubes.

As described, I tested this with my hands. Starting the ventilation I can build a ring with both hands (15 cm diameter) and try to keep the hot air stream in the middle. This way I can place the end of the tube exactly. But this works without funnel only.

For me this works perfectly and I never had any smell (like a swimming pool) any more. Or throught and breathing issues that I had before. Even when I give classes and have 6 torches firing I don't need to run my fan full power (200 Watt / 1200 m³/h).

Yes Munich to Prague is less than 4 hours by car.

Good luck with your studio,
Florian

The problem with inline fans is that they are designed to transport air from one place to another through a smooth duct not to create high suction at an opening. These fans work better at removing exhaust for lampworking when they are hooked up to a large overhead exhaust hood where the fumes can naturally rise up and be forced into the exhaust tube by the shape of the hood. The length of the exhaust tube and the position of the fan, as well as the fact that the tube is corrugated vs. smooth all have impacts on the amount of air you're actually moving. If the free rating of the fan is around 400 CFM, I would guess that you're getting something around 250 CFM once it's hooked up.

Because the fan is far from the funnel opening there's likely to be very little suction at the opening of the funnel, and what suction there is drops off very quickly to nothing as you move away from the face of the funnel. So for the fumes to go through the exhaust tube they have be pushed in by the force of the torch flame. Heat and exhaust products are rising up in column from the top of the entire flame, not just the tip, and those probably don't get captured by your exhaust. Also when mandrels and glass rods are placed in the flame they cause turbulence so the fumes are scattered around and mixed with air that rises up and fills the room polluting your breathing air.

Assuming there's enough makeup air and that the makeup air source isn't being polluted by the exhaust, either using an overhead exhaust hood or placing another exhaust fan up higher toward the ceiling could help.

Does it pass the smoke test?

I've found a smoke test to be a poor indicator of the quality of the ventilation because smoke from say a burning piece of paper or incense is very lazy, any amount of air flow will capture it and move it along.

If however, the smoke has velocity such that it can escape the suction of the fan it's going to collect in the head space of the room. When that happens it's like filling a pool upside down where the fumes gather and move downward. They will eventually reach the exhaust, but if it's lower than head height you'll be inhaling them at the same time.

This is the thread I was searching for. There are a lot of links in it which helped me a lot.

http://www.lampworketc.com/forums/sh...ht=ventilation

A fume hood or Barley box is really the best option for capturing the fumes. And with that, I'm out.

Thanks everyone, you are great support...

I´ve done smoke test many times, it works perfectly, but probably the smoke from the torch moves differently - exactly what Talonst mentioned

On the other hand the movement of air around the funnel causes that my flame moves quite a bit which causes troubles when applying stringers etc. I dont think it is normal... the movement of air is not caused by the air coming from the window, even if I shut it...

No problem to purchase a Barley box, move the table, make unother hole in unother wall... do you thing that this type of fan, inline, will work when attached to the back side of the box, exactly between the hole in the back of box and the hole in the wall...so no tubing would be there...I would obviously put it in the centre just bellow the ceiling of the box... I would probably have problems to put the fan above the box and make the hole somewhere there...

Thanks and have great day, Miscia

When I work without ventilation my chest feels really awful and I might eventually get a headache all of which will go away within an hour or two away from the torch. I have had no symptoms whatsoever from torching without ventilation like a sore throat like you described. That however is exactly how I feel around dust or mold. Is it possible you are having allergies to something in the spare room and the problem is not the ventilation or lampworking?

There is much good advice above, but I was wondering if you sit very close to the torch? the closer you are, the more likely you are to be inhaling fumes.

Thanks for your opinion, interesting, you work without ventilation and do not have breathing problems? i have it with wentilation and it lasts for some days... there is no dust in the room, it used to be my daughters room, absolutelly clean ...it has to do with torching only...but maybe an alergy to something in the glass...more than a headache I have the problem it in my breathing system...well, not nice, but can be it!

miscia

I read this comments about the Barley box and honestly I have never used it.

But my understanding is: The sooner you suck the used air into any tubes the better. As you can see on my pictures my system is leading the air upwards, where the temperature would bring it anyway.

As I said I haven't tested a Barley box, but this means the air has to go up to the hood and get's sucked in from full width. This way it get's unused air and the used one has time to mix with the unused one. Not sure if that is as efficient as a exactly positioned tube.

As I described, I use my hands to feel the temperature. And in that case the temperature is identical with the used air. Meaning, if the hot air stream is sucked into the tube and you can move your hands around the opening of the tube, this is the maximum you can reach. I tested this even with holding a large bead into the flame and it get's all sucked in.

Barley box is a big advantage if you use different positions or torches, so you don't need to change the tube angle all the time to have the best position.

But I still don't have any idea why you have the symptoms with the exhaust.

I know a bead maker who presses the body against the torch, so that the nose is very close to the flame. She always had to drink a lot to reduce the effects caused by the radiant heat (very different with different torches).

Hope you find a good solution soon.

Thanks for your support. I have tried your method with hands, removed the funnel, no way... What I am doing is moving the torch/table to opposite external wall and so will have no tubing...will try Barley box with the fan attached to the back side and exhaust directly out... something between your solution and standart B box. I have an impression that the air is moving around the end of my current tubing, maybe because of the type of tubing and its way, even the flame is moving ...and yes I´m sitting very near, my head above the torch... Asap I will post a picture... thanks again... have a great day...if and when I resolve the problem I was thinking about your bottle glass lessons...do you do any in english? I speak very basic german only...

Miscia,

the next two bottle classes are fully booked, but I'm sure there will be more in future. If you want to get informed, just send me a private message with your email address. This way I can notify you about upcoming courses. I could do it bilingual.

Florian

I generally work with excellent ventilation as I make beads full time. I have had to finish beads during power outages and have worked in other studios without proper ventilation so I know how it affects me with just a really uncomfortable feeling in my lungs. Allergies affect me the same way only with a sore throat and the feeling that my throat is closing off. I just developed a severe dust mite allergy so the culprit can be anything, bedding, carpets, coats, etc.

After looking at your photo I'm fairly confident that this is your problem... you are trying to pump HOT air down toward the floor. Hot air rises along with your fumes so it's easy to pump those fumes up and out. You might possibly get away with pumping them down only if you had a very powerful fan located before the ducting starts to get directed down. Instead your fan is located on the floor after a long run of curved flexible tubing. Every curve, turn or elbow joint really hurts the efficiency of your system further. Unfortunately most of the fumes aren't even reaching that fan.

Could you possibly rework the system putting the fan or preferably a more powerful fan at the highest point in the ducting, where you have it attached to the wall?

The funnel does help the system draw in much the same way a pyramid shaped hood does. All of the commercially available ventilators like this have these. I believe the issue is that the fan is undersized and there is flexible ducting used. Based on what I see in the picture you should have a fan that will move twice this amount of air or 800-900 CFM. Part of the problem is also the flexible ducting you used. It creates turbulence and adversely effects the efficiency of the system. Based on my experience this system will be underpowered.