Sciencemadness Discussion Board

Fume hood substitute

thesmug - 16-2-2014 at 11:09

It's very cold where I live so doing reactions outside is not an option, and there are several reactions I would like to do that require good ventilation. I don't have the space or budget for a fume hood, so what are some good substitutes that will provide good ventilation?

[Edited on 2/16/14 by thesmug]

Brain&Force - 16-2-2014 at 11:17

Do you have any particular reactions in mind? It might be a good idea to do certain experiments out in the cold in case you need cooling. See this thread: http://www.sciencemadness.org/talk/viewthread.php?tid=28777

You could always build one if you had the time and money. But sometimes a range hood will suffice if the gas is not particularly toxic, just a nuisance.

thesmug - 16-2-2014 at 11:18

Quote: Originally posted by Brain&Force  
Do you have any particular reactions in mind? It might be a good idea to do certain experiments out in the cold in case you need cooling. See this thread: http://www.sciencemadness.org/talk/viewthread.php?tid=28777

You could always build one if you had the time and money. But sometimes a range hood will suffice if the gas is not particularly toxic, just a nuisance.


I was going to make iodine or maybe even bromine. Also, do the fumes from HCl and H2SO4 make them too dangerous to work with indoors?

Brain&Force - 16-2-2014 at 11:28

Depends on what you're doing - making iodine shouldn't be any trouble fumewise (but it will make a mess). It's a good idea to make bromine in the cold. It saves you from nasty fumes, and depending on the temperature, will allow you to crystallize the product.

As long as you're not making chlorine gas or sulfur oxides with the acids listed, there should be no problem. Just don't inhale them intentionally. (37% HCl does fume a lot, so it's advisable to work with it in a fume hood or outside.)

thesmug - 16-2-2014 at 11:34

Quote: Originally posted by Brain&Force  
Depends on what you're doing - making iodine shouldn't be any trouble fumewise (but it will make a mess). It's a good idea to make bromine in the cold. It saves you from nasty fumes, and depending on the temperature, will allow you to crystallize the product.

As long as you're not making chlorine gas or sulfur oxides with the acids listed, there should be no problem. Just don't inhale them intentionally. (37% HCl does fume a lot, so it's advisable to work with it in a fume hood or outside.)


I work in the basement, but the room I work in has an exhaust fan in the ceiling and a window. Would working with the fan on and the window open provide good ventilation?

blogfast25 - 16-2-2014 at 12:58

Quote: Originally posted by thesmug  

I work in the basement, but the room I work in has an exhaust fan in the ceiling and a window. Would working with the fan on and the window open provide good ventilation?


It's a lot better than nothing of course. An improvement could be to invest in one of these wide, flexible tubes, about the with of your exhaust fan. Then you can move the open end of the tube over the reaction area when you're working. With the fan on full, you're basically vacuuming off the reaction gases. I've been meaning to get such a system but haven't gotten round to it.

But nothing beats a functioning fume hood.

organicchemist25 - 17-2-2014 at 10:28

Here is one I built for under 100.00$. I did install a organic vapor inline filter, but that is not always necessary. So, if you can swing about 90.00$ it would be a long lasting, convenient investment.

ddd.jpg - 42kB

organicchemist25 - 17-2-2014 at 10:30

oh, and if you would like my exact measurements and links to the fan and all the specs etc, I can provide that too to save a little time. Its worth building imo. and there is a plexiglass shield in the front, it might not be visible in the pic.

[Edited on 17-2-2014 by organicchemist25]

blogfast25 - 17-2-2014 at 11:56

Quote: Originally posted by organicchemist25  
oh, and if you would like my exact measurements and links to the fan and all the specs etc, I can provide that too to save a little time. Its worth building imo. and there is a plexiglass shield in the front, it might not be visible in the pic.

[Edited on 17-2-2014 by organicchemist25]


And you've built this inside your nuclear shelter? ;)

MrHomeScientist - 18-2-2014 at 08:21

Either that or he lives inside a baked potato :o

@thesmug: What quantities are you using? If you're doing test-tube scale reactions, a bit of acid/halogen fumes shouldn't harm anything. If you're producing lots of bromine or throwing gallons of acid around, a fume hood would be advisable. Sulfuric acid does not fume.

As an alternative to the traditional method of distilling bromine, consider the electrolytic route. Really minimizes fumes, at the cost of taking a long time. I got the procedure from woelen, and made two videos on the process: http://www.youtube.com/watch?v=NKjyM2AkZSY
It's one of my favorite experiments I've ever done. Tons of fun, and bromine is probably my favorite element. I'd still recommend doing everything after the electrolysis portion outside, though.

blogfast25 - 18-2-2014 at 11:03

Quote: Originally posted by MrHomeScientist  
Either that or he lives inside a baked potato :o



Lol. It has a bit of a 'Dr Frankenstein, I presume?' feel to it. Mwhahaha...

Still, one must seriously admire the dedication to his trade!

Zyklon-A - 18-2-2014 at 11:16

Yeah, it's a very nice lab, looks like it's in a shed, with Al sheets for insulation. If your lab's in a shed, you certainly need a fume hood.

[Edited on 18-2-2014 by Zyklonb]

thesmug - 18-2-2014 at 21:08

Quote: Originally posted by MrHomeScientist  
@thesmug: What quantities are you using? If you're doing test-tube scale reactions, a bit of acid/halogen fumes shouldn't harm anything. If you're producing lots of bromine or throwing gallons of acid around, a fume hood would be advisable. Sulfuric acid does not fume.

As an alternative to the traditional method of distilling bromine, consider the electrolytic route. Really minimizes fumes, at the cost of taking a long time. I got the procedure from woelen, and made two videos on the process: http://www.youtube.com/watch?v=NKjyM2AkZSY
It's one of my favorite experiments I've ever done. Tons of fun, and bromine is probably my favorite element. I'd still recommend doing everything after the electrolysis portion outside, though.


I expect to work on test tube to medium (around 50 ml) scale. I haven't seen that procedure before. Maybe I'll try it!