Homemade HEPA Solder Fume Extractor

[ECEdesign]

So I was thinking about getting one of the Hakko fume extractors but they seem pretty expensive for just a fan and charcoal filter in a box.  I am using a box fan on my desk to blow the fumes away which works great but I am moving to a much smaller location for my lab and having the fumes circulating in the room is probably not going to be good. 

The 'big boy' fume extractors are extremely expensive for a bigger filter in a box so I was thinking about getting a HEPA and charcoal filter and fitting them to a booster fan http://www.amazon.com/TerraBloom-Booster-Inline-Ventilation-Exhaust/dp/B00WW4H8XY/ref=sr_1_3?ie=UTF8&qid=1462136665&sr=8-3&keywords=booster+fan.  Does this sound like it would work?  What have other people done for fume control?

[uncle_bob]

Hi

The HEPA filter will do particles. If you get a real one (like for a clean room) they aren't cheap. A furnace filter with "HEPA" on the label is a *lot* cheaper (and much less effective). Some things bother one person and not another. The only perfect answer is to blow everything outside and bring in new / clean air. (A hole in the wall beats any filter). If an outside vent is not possible, you are into a try it and see sort of thing.

Bob

[ECEdesign]

Yeah I was looking at a "true HEPA" replacement filter from honeywell. A small one was around $20.  I am sure the clean room ones work good but definitely out of my price range. The more I think about it though the better the little Hakko sounds.  No fiddling with cutting filters and such just a nice small device.

[uncle_bob]

Hi

If you are going to use furnace filters, make the box big enough to use one without cutting. You simply will not put up with chopping things for very long ....

Bob

[IconicPCB]

There is a DIY electronic air filter which has some incredible performance specs.

It consists of a high voltage DC source ( perhaps 1KV DC) and a three layers of coarse metallic fly wire screens with two layers of very coarse glass fibre filter media.

So we are talking interleaving the media between wire mesh.
The outside layers of wire mesh are joined together and connected to one side of the HV supply.
The midle wire mesh is connected to the other side of the HV supply.

When energised the effective filter density goes up trapping particles and causing them to adhere to the media fibres ( electrostatics).

The demonstration I have seen is a filter box about the size of a shoe box getting filled with cigarette smoke, the volume is recirculated through the filter usinf a small ( computer size fan) and within 10 to 20 seconds the air is clear and the media reeks of tobacco smoke.

No reason it oughtn't work on solder fumes.

HV derived from an oscillator running on 24V ( + ferrite core tranny and rectifier ).

[uncle_bob]

Hi

The problem with an electrostatic precipitator on solder fumes is that they may have a lot of non-polar organic "stuff" in them. A conventional filter could not care less if the particle is charged or not. Also a conventional filter will work to some very limited degree on the tar like fumes that aren't quite particles, but are not quite a normal gas either.

Bob

[timb]

There is a DIY electronic air filter which has some incredible performance specs.

It consists of a high voltage DC source ( perhaps 1KV DC) and a three layers of coarse metallic fly wire screens with two layers of very coarse glass fibre filter media.

So we are talking interleaving the media between wire mesh.
The outside layers of wire mesh are joined together and connected to one side of the HV supply.
The midle wire mesh is connected to the other side of the HV supply.

When energised the effective filter density goes up trapping particles and causing them to adhere to the media fibres ( electrostatics).

The demonstration I have seen is a filter box about the size of a shoe box getting filled with cigarette smoke, the volume is recirculated through the filter usinf a small ( computer size fan) and within 10 to 20 seconds the air is clear and the media reeks of tobacco smoke.

No reason it oughtn't work on solder fumes.

HV derived from an oscillator running on 24V ( + ferrite core tranny and rectifier ).

Got a link? I wonder if it would work better with something like fine SS316 mesh? (#500 is ultra fine, feels like silk!)

[sarepairman2]

i suggest you build it by a window and blow the shit outside instead

[IconicPCB]

Uncle Bob

It is not an electrostatic precip.. it uses a media .



Timb,

http://www.cimatec.com/Cimatec-Air-Filter-AirScreen1000.aspx

[uncle_bob]

Hi

If you have a great big (relatively speaking) furnace filter, it's not going to have a whole lot of back pressure at low air volumes. You don't *need* the same amount of airflow in a small room you need to ventilate a whole house. Grab a random computer fan and see how it does with your target filter. All it takes is a cardboard box and some tape. You will know mighty fast if that's enough air or not. If you need to go to a blower, there are DC blowers out there that will do the job. eBay will give you a bazillion listings for them.

Bob

[ECEdesign]

I think I'm just going to get a Tenma fume extractor and not worry about it.  Too much messing around with the DIY version...  http://www.newark.com/tenma/21-7960/solder-fume-extractor/dp/37J0035

[uncle_bob]

I think I'm just going to get a Tenma fume extractor and not worry about it.  Too much messing around with the DIY version...  http://www.newark.com/tenma/21-7960/solder-fume-extractor/dp/37J0035

Hi

Check the price / availability of replacement filters. I have absolutely no idea how much they cost or if they are available. I'm not suggesting they are over priced, only that it's worth checking.

Bob