This instructable shows you how to make an air purifier to filter pollutants such as tobacco smoke, solder fumes and many other organic materials out of the air that you breathe.

Step 1: Needed materials and Basic Idea

Computer fan
Activated Carbon
Window screen
Modeler's plywood
Basswood or balsa
12 volt AC/DC converter

If you have enough modeler's plywood, then you can make the frame out of that, but to save money, I chose to glue my frame together with some balsa wood I had. I had everything but the activated carbon, which you can purchase at pet stores, already at my house.

The purifier works by drawing air through the carbon and forcing it out through the top. The picture below is a cutaway view. The carbon surrounds the purifier on four walls with the fan on the top. The large surface area allows the air to pass through slowly which cleans the air much better.


<p>how much it will cost</p>
cant you make carbon??? i saw in a science book you add something to sulfic acid and carbon is made :-\?
<p>charcoal is a fairly concentrated form of carbon, activated charcoal is the filter media... and yes you cam make it.</p>
I dont think you can make carbon, unless you do some nuclear fission or fusion of lighter or heavier atomic nuclei. Carbon is an element.
oh i remember, if you put sugar into a thing of sulfuric acid, you can make carbon! thats all :-)
Or you could just burn some wood...
You can activate normal carbon, I have done it. You just heat it. you can also reactivate spent activated carbon the same way, it drives off the impurities it has collected.<br />
that was qutie funny
Actually, the carbon is already there; the chemical reaction just separates it and takes it out of the sugar. However, you'd end up with a big, black blob of metal. . . Not much you can or would want to do with that.
Um...you can make <em>carbon ash</em> (charcoal) by burning wood, but in this case you need activated charcoal.<br />
This device is exactly what I am looking for, but one question: How do you attach the 12 volt AC/DC converter to the fan wires?
There is just a positive and negative wire coming out of the fan and I hook that up to the positive and negative output of the power supply. Its as simple at that.
ah yes but be careful when doing so i would recomend getting all of your connections together and semi-permanently fastened BEFORE even plugging it in and i mean i know it is dc but what if the transformer where to break just then? ill tell you what you would have a positivie and a negative end of AC power going from one hand through your chest and heart, to the other
12 volts isn't really enough to break the skin and get into the body, so there really isn't much danger. But anytime you work with electricity you need to take precautions.
Well, you won't feel 12V. But if the amperage is high enough, it'll kill you if you let it arc across your heart.
12v cant arc across your body. The resistance of skin is too much. In any normal case, when working with 12v and under it is impossible to shock yourself unless you soak yourself in water for a few days.
If you actually READ what I wrote you will realize that I said &quot;If the AMPERAGE is high enough, it'll kill you if you let it arc across your heart&quot;. Bad read^. AMPERAGE IS THE KEY WORD HERE. Google it if you don't know what that means.
<p>Ohm's law will tell you that the amperage flowing through you from skin contact is limited by the resistance of your skin. It doesn't matter how much amperage is available, at 12v with a typical skin resistance of 100k ohm you have a current limit of .00012 amps. It takes at least .01 amps to kill you. So you need at least 120 volts to kill a human through typical skin contact. And the current has to be sustained for some time to do the job, many people get electrocuted by 120v across the heart without dying, but it is because the exposure was short. As the voltage goes up, your ability to pull away from contact goes down AND the potential lethal danger goes up. 120v gives you a good jolt, but 400v tends to just kill right away.... but not always.</p><p>HOWEVER, if you break the skin on both sides of the circuit, resistance falls to 500 to 1000 ohms. But you have to beak the skin /twice/, on opposite sides of the heart. If you break the skin on only one contact, you still have a 50k ohm resistance to deal with.</p><p>This is why people don't die when installing car batteries, where you might have 600 to 1000 amps or more of 13.8vDC available, and plenty of scraped knuckles (broken skin).</p><p>But I have heard of someone killing themselves with a ohm meter powered by a 9v battery because they tested the resistance of their body using very sharp probes that pierced the skin. I don't know if that story was true, but at 900 ohms, a 9v battery can produce the deadly .01 amps.</p><p>You are right that it's not the volts, but the amps that kill you, but ohm's law predicts you are unlikely to ever see lethal amps from 12v. Breaking the skin not once but twice on both hands is required to make 12v dangerous. But even the smallest 12v power source I can think of can do .01 amp.</p><p>An old electrician's trick, work with one hand in your pocket when touching a live circuit with a tool (any tool, even insulated tools designed for this), and wear clothes and shoes to provide enough resistance for whatever voltage you are working near. Better electricians use gloves that they test frequently.</p>
You need voltage for amperage to kill!!!<br>I have put my fingers across a 12v 5a source and i didnt feel anything. You need at least 40 volts with moist skin to even feel anything.
Think of electricity like water. If you put your finger at the end of the faucet no water flows. This is like low voltage (pressure of water is low) and no amperage (there is no water coming out.) If you are using a hose, there is some water leakage because the pressure is higher so it means that amps are flowing. Basically you need some voltage to make amperage effective enough to kill.
30mA kills a person at 230v,<br>Ampere = Volts/Resistance, in this case 12v / 1000r (resistance of the skin)<br>Therefore Wally_Z's arguments are invalid.
Yeah yuo are rigth! V=R*I (V=Voltage in volts , R=resistance in omhs and I is current in amperes),WELL this is the OHM Law,and on the other side any DIELECTRIC have a constant, a point that change from not conductor to a conductor(For example the dialectric constant of the air is about 3 Kilovots(3000 vols)...so taht explain the spectaculr pictures of tesla or the ligting)..
THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!<br>Some people need to know what they are talking about, SERIOUSLY!!!!
cut the wire open and solder the + to the red and _ to the black. If you cant tell which is + and - guess and if the fan doesnt work, switch the wires.
<p>Air filtration is frequently recommended as a component of environmental control measures for patients with allergic respiratory disease. Residential air filtration can be provided by whole house filtration via the home&rsquo;s heating,<br>ventilation, or air conditioning system, by portable room air cleaners, or a combination of the two. By &lt;a href=&quot;https://www.demoport.in/home-products-services/air-purifiers-humidifiers? &quot;&gt;Air purifiers in chennai&lt;/a&gt;</p>
<p>Environmental control practices (ECPs) are a group of measures recommended to reduce exposure to indoor allergens (eg, dust mites, household pets, cockroaches, mold, mice) or nonallergic triggers (eg, environmental tobacco smoke [ETS], <br>wood smoke, volatile organic compounds, particulate matter [PM]) [1]. Historically, many of the common suggestions have been empiric and not based on scientific data or evidence-based clinical trials.By &lt;a href=&quot;https://www.demoport.in/home-products-services/air-purifiers-humidifiers? &quot;&gt;best Air purifiers in chennai&lt;/a&gt;</p>
<p>Here's a link to a website where you can purchase activated carbon filter products.</p><p>http://www.5starfilter.com/Carbon-Media-and-Filters-s/1847.htm</p>
<p>Absolutely brilliant! Great job covering the steps and including photos. Thanks for posting this. Would you mind if I post a link to this on a blog?<br><br></p>
<p>did you make this product as a filter for vehicles?</p>
Great Idea, One idea though: <br> <br>You can buy these dryer sheets that are designed to give you clothes a nice smell, you should buy a box of them and tape them to the window screen.
<p>Activated carbon physically captures pollutants. Dryer sheets just mask odors.</p>
Hi. Is it possible to use activated carbon as car smoke filters?
<p>I like this. Looks like I could make a less precise version out of anything, even popsicle sticks. I'm curious about the air flow, though. Especially after the carbon has settled, how hard is that fan working? I ask because I'd want to reverse the direction of the flow and make it flatter rather than cubed. Like you said, forced air is more difficult. Also, how often would the carbon need to be refreshed?</p>
<p>The fan doesn't work very hard due to the large surface area of carbon. This allows the air to move slowly through the carbon which reduces the load on the fan. Making the filter flat is possible as long as you maximize the surface area of the carbon.</p><p>I replace the carbon about once per year.</p>
<p>this is nice... and i could use it as a base research for my papers... thanks... but could a fan run in a 5 volts ac??</p>
<p>All computer fans use DC and most 12 volts. If you want to use AC power, you need an AC fan.</p>
Would this work for scrubbing ammonia gases from pet litter?
<p>Yes. It will reduce the smell from a litter box.</p>
<p>Activated coconut carbon, Bentre provine, Vietnam</p>
i have found something better than aquarium carbon.<br><br>you can buy surgical masks that have a type of active carbon material layered between two needle punched non-woven fabric they are great.<br><br>the needle punched fabric filters out dust<br>and the active carbon material can filter out bad smells <br>the surgical mask can also filter out viruses and bacteria so it works like a hepa filter! all you have to do is cut of the ear loops and the sides so the pleats open up then you can use it. it costs like &pound;3.00 for 50 masks so it is so cheap and they last for about 1 month.
you might actually try three fans in line. say for argument's sake the first fan gives you one bar of pressure, a second in line would double that to about 2.3 bar of pressure and a third would then daouble that to about 4.6 bar. in theory that is.
this could be good for a solder venting system
It actually does work as a solder venting system. The only problem is that it doesn't suck in air at a high enough velocity to make it effective. Even though it does suck solder fumes in and filter them very well, most of the fumes just go straight to my nose. If I wanted to make one, I would probably only have one side of carbon, use a converging nozzle into the fan, and only use a .25" thick wall of carbon. This would allow for a much greater airflow and, hopefully, pull the fumes away from my face. But, since I don't solder much, I think I can do without it.
Instead of 4 inlet vents try limiting it to 1 so that the air pressure is not 'diluted' and you will have greater suction towards four soldering station... And also, the fumes going to your face are harmless, after going through the filter...
increase venting CFMs (cubic feet per minute, flow rate) by making a grid of four fans to draw the air. or whatever amount is necessary. the air velocity through the filter should be 200 feet per minute, and big enough to catch all the fumes. quick calculation

About This Instructable




More by Hatty:Activated Carbon Air Filter 
Add instructable to: