Sciencemadness Discussion Board

Exhaust fumes through the kitchen fan?

nannah - 20-9-2014 at 06:03

Hi, i will soon try my first ever experiments. I have decided to start with some simple electrochem reactions, like making NaOH and metal salts.
I will also make some mash with the intention to purify it to at least 96%. This through distillation and later drying with CaO. This one scares me the most.
I have been putting this off for a long time for several different reasons, but next week i will get the wires thats last needed for the electro stuff, and i'll be ready for some science. :)

Anyway, the thing is that i dont have a way to extract fumes to outside and was wondering if the kitchen fan can be used if i hang some sort of plastic sheeting, or if a cardboard box thats modified so it attach to the hood. I dont know.

Anybody done this and can share their experience?

Thanks guys. :)

/nannah.

Bert - 20-9-2014 at 06:35

I suggest NOT doing chemistry in the kitchen, or keeping chemicals in the kitchen refrigerator... Against the day you work with something toxic or noxious. Work outside, or build a hood.

If you are doing chemistry in the kitchen and living with others, you will end up either severely pissing them off or possibly killing them.

nannah - 20-9-2014 at 07:20

Yeah, you are right. I dont want to harm my family just becouse of a hobby project sake. And i would never keep toxic chemicals in the fridge. No way.
Even if you would recommend me to usecthe kitchen fan, i dont think that i would have done it.

I have to make a hood then. If i do it outside that i really want to do i am afraid the neigbors will call the police and i will get busted for making moonshine. :(

forgottenpassword - 20-9-2014 at 07:43

Firstly you should plan to create as few fumes as possible. When distilling you can have a length of PVC tubing leading from the vent of the receiving adapter out to a window. When refluxing you can attach a length of tubing from the top of the condenser out to a window -- and so on.
You will need to work out a place in your house/garage/shed where you can work -- and where there is a window to vent any volatile solvents.

Oxirane - 20-9-2014 at 09:33

In general it's not a good idea to do chemistry in kitchen, unless you live alone, do only chemistry that involves low toxicity chemicals and can contain the reactions and exhaust the fumes. Many houses do have exhaust up to the roof, and technically you could make a hood. But if you have any possibility, make a separate hood from cheap wood, coat it with inert plastic and get a duct fan, and if you live near other people, get an activated carbon filter and attach it to the fan, this will neutralize moderate concentrations of even the more toxic fumes. Do not perform toxic experiments (like cyanides) in living quarters.

If you are making alcohol, get yourself an active carbon filter. I have used these to make as large as 200 liters drum batches of alcohol in my small apartment with zero smell. The distillation process itself doesn't smell, just remember to pour the yeast mixture through a sand filter to clarify it, otherwise it may burn.

[Edited on 20-9-2014 by Oxirane]

Microtek - 22-9-2014 at 04:30

There are many similarities between a lab and a kitchen, and I have frequently used one for my experiments. At the time, it was not used for cooking though, which reduced the potential for mishap.
I agree with the posters above, that generally you should use a dedicated lab and fume hood, but having said that, I will say that a kitchen fan (if yours looks like mine) is just fine for venting fumes.

Bert - 22-9-2014 at 08:34

One aspect of kitchen stove hoods- I have seen installs where the hood merely filters the air of grease with metal mesh panels, then discharge air directly back into the kitchen! Not a happy thing if you REALLY needed a fume hood...

Dr.Bob - 22-9-2014 at 11:25

Plus, most stoves and their hoods have switches and/or motors that create sparks, so working with any flammable liquids there is really asking for a fire to start. They are designed to work well with water and steam, which are not typically fire hazards. Any organic experiments with flammable solvents are best done in a garage, shed, outside, or in some place which, where there is not food or spark sources. There are some experiments which are suitable for indoors, but you should think about them before doing indoors. Ask yourself what would happen if the flask broke, the reaction caught fire, or someone were to inject some of it before doing work inside.

Even brewing beer can create some powerful smells, sticky goos, and burns/ fires when boiling the mash. My friends who brew have learned not to do it in the kitchen, better working on a deck or in the garage, where the floor can be washed with a hose. If beer can make a mess, just imagine what your nitric acid can do.

Oxirane - 22-9-2014 at 19:27

Ex proof fans are mandatory while handling large amounts of continuous aerosols or vapors. Occasional amounts of contained flammables are not an issue. This means you can do experiments with few hundreds of ml's of ethanol and acetone and other stuff that's mostly in flasks and bottles, NOT pouring a liter of ether on an open pan. The lower explosion level is different on every vapor, but in general one will need to create several grams of vapors to cause ignition. This is another of those "common sense" things we face in this hobby.

aga - 23-9-2014 at 13:27

Lab is for chemistry, and can be anywhere.

Kitchen is where Food happens.

Always keep the two in separate locations.

chemrox - 24-9-2014 at 15:25

I've never run the expense of explosion proof fans. I don't generate enough H2 at one time to warrant the cost. Kitchen exhaust fans, even when they discharge to outside air, are usually way to weak to evacuate a suitable volume. A hood must have a fan capable of clearing the lab air every two minutes. A box fan over a windows is better than a kitchen exhaust.

Dr.Bob - 24-9-2014 at 15:59

The first place I worked part time at had a hood consisting of a plywood box around a window with a box fan in it. But since of the chemicals there were more toxic than flammable, that worked pretty well. As stated above, the quantities and types of chemicals dictate the concern needed. But if you work with corrosives or lots of flammables, then ventilation is key.

nannah - 25-9-2014 at 00:55

After reading all your tips. I got one "aha" moment there with attaching tubing to the apparatus and lead it out the window.
I have to say that i have always hesitated using the kitchen, but its the only place i can hook up a aspirator if i needed it. I forgot to mention that in the first post. It was good hearing your opinions and what you got to say.

So i am thinking about buying a vacuum pump so i can use the garden shed instead. I just have to put a vent in the wall so i can lead fumes outside.

What kind of pump would you buy if you were on a budget? I have about 100-200 usd to spend.

Thanks guys.

aga - 25-9-2014 at 11:49

Quote: Originally posted by nannah  
What kind of pump would you buy if you were on a budget? I have about 100-200 usd to spend.

You mean for the water circulation in the condenser ?

I use a 'Whale Subby' pump in a bucket with a 12v car battery

http://www.ebay.co.uk/itm/Genuine-Whale-Caravan-Water-Pump-S...

Need colder water ? Change Bucket and/or add ice to bucket.

CuReUS - 26-9-2014 at 00:04

Quote: Originally posted by nannah  


So i am thinking about buying a vacuum pump so i can use the garden shed instead. I just have to put a vent in the wall so i can lead fumes outside.

What kind of pump would you buy if you were on a budget? I have about 100-200 usd to spend.

Thanks guys.


you can make a fume hood from a leaf blower

read this book- it tells you how to modify a leaf blower to function as a fume hood exhaust (see page 22-23)

this is not a pdf so you will need djvu reader
so first install this-http://windjview.sourceforge.net/
all the best for your experiments:)

Attachment: Total Synthesis II (Strike).djvu (2MB)
This file has been downloaded 391 times

[Edited on 26-9-2014 by CuReUS]

nannah - 26-9-2014 at 05:37

Aga: I have read about those, and i would very much to make one of my own. I love to have small projects in my free time, but thats in the future.

I have started thinking about using my storage shed for my various projects. I just have to isolate the walls and the ceiling. Its super cold in the winter, and hot as hell during the summer.
Anybody done this? Isolation i mean. :)

Cureus: I will download it. Any particular pages? I actually have a leafblower. :)

Thanks guys. :)

Ps. Would a single stage rotary vane pump (1,8 cfm) be a good choice for me?

[Edited on 26-9-2014 by nannah]

CuReUS - 27-9-2014 at 04:15

Quote: Originally posted by nannah  


Cureus: I will download it. Any particular pages? I actually have a leafblower. :)



see page 22-23

nannah - 28-9-2014 at 09:13

Thanks cureus. I'll check it out. :)