Build a do-it-yourself air purifier for about $25

[airfilterguy]

This demonstration shows the use of an Accumulair Diamond MERV 13 filter. In independent testing, Accumulair's polyurethane filter media has been shown to emit a sharp sweet odor, similar to that of ozone. We're currently researching its potential ban by the California EPA for its intended purpose of mediating indoor air.

Similar filters by other brands have yielded odor-free air. Until further testing confirms the source of Accumulair filters' odors, use more reputable brands.

[ella5024]

I've been doing this for years. I thought of it myself. I put mine on the back of the fan, taping it on to seal every bit of leakage. I use duck tape.

[DGunlock1]

You should consider the motor being used in the fan - if it is a sealed motor it produces no ozone, if not it will. In the case of this example fan unit - I think it is not a sealed motor. I don't know how much ozone can accumulate, but if it runs constantly it may be considerable.

My wife and I notice that we feel pretty crappy in the morning when we run a heater or fan all night that is not a sealed motor.

[RaikaMelody]

Hey, can anyone please tell me what he says at 0:43 - 0:48? He says "This system is a loan to us from---" and then I don't understand what he said.

[Muaddib26]

@RaikaMelody ''and our vacuum''

[RaikaMelody]

@Muaddib26

Oh, thank you very much!

[Muaddib26]

@RaikaMelody no prblm. ;)

[etcurrie]

no sound. please fix or take it down

[BOOSTEDLASER]

If filter is on back, the front pulls massive air from the front.It comes from the corners of the box.THis front air is 100% UN filtered. On my meter with 1 filter on front I get over 90% reduction. With one filter on back I get less then 30% clean air.NEVER put ( only ) on back.

[JimsGeminiTube]

I would put the filter on the back side of the fan.

[BOOSTEDLASER]

Check my DIY hepa filter build : Youtube: BOOSTEDLASER

[1crazyfocker]

blah blah blah.... once again try reading what i said, man you really just prove my point, i guess i should have grunted instead of snorted then, i never said anything about a fire hazard or what type of filter to use, in fact i like the idea and do use it, but seeing how you cant even read a simple comment in context, kinda says a lot.... next time you try to make your self sound smart trolling try picking a comment that says "fire hazard" or is agianst the video, HA HA HA

[BOOSTEDLASER]

Q: "How long do filters last" A: Depends on how dusty things are.Depends on many things, time of year, type of materials room /house is made of,type of carpet ect ect.Also using a "pre filter" is key. Not just does this remove extra stuff,it also saves the main filter, making it last longer.Using a washable prefilter or super cheapie is what I do.Also I clean mine outside now and again with a Datavac ED500. So far my bedroom setup is over 6mo old and has more time left. I will make a video.

[BOOSTEDLASER]

Used an infared temp gun on my filter setup that ran 12 hours.Motor temp is 11 deg above ambient temp.This is NO fire hazard.For a goof I will check a stock naked fan and check the temp.Will also run my watt meter on both fans to see draw diff.

[BOOSTEDLASER]

BTW: A Hepa filter is HUGE resistance.Take a hepa filter out of any machine and run it naked...you will get 10x more air.Its just simple physics.The deeper the filter media and the closer the pleats the more it resists ( and filters)... As a pro drag racer and speed shop owner,I wounder how a large K$N filter would do as an air cleaner for the house =P. I wonder if K&N have any CADR ratings =P. I may look into this and retrofit somthing.

[pinkfloydeffect]

How long do these filters last?? My glass desk collects dust in just 1 day!

[danctharp]

DO NOT DO THIS. This is a huge fire hazard. These fan motors are designed for a certain amount of resistance. The extra resistance from the filter can cause the motor to over heat and start a fire. This is a horrible idea and Michigan Sinus Center should be ashamed of themselves.

[EdKLunar]

@danctharp Maybe you should be ashamed of yourself. Hepa filters are designed to provide minimal air resistance. As they fill up with dust they provide more resistance. If one were to change the filter often it might not create too much blockage. Some of those fans have an overheat shut off too, in case there is too much blockage. It might be a good idea, might not. Unless you can provide numerical specs you just sound like a spokesperson for underwriters laboratory or the govt.

[filterAfan]

Very good video! Thank you. Another inexpensive option is a plastic shroud that attaches to box fans called filterAfan.  There are videos on YouTube for filterAfan. Thanks!

[FijifunXP]

Very cool...I dont know too much about a HEPA filter. Does it reduce odors coming through too? or can I put a carbon filter in front of the box fan?

[HeroOfTheWeb]

Why not in behind the fan? The blades will get dirty if you do it this way.

[1crazyfocker]

@HeroOfTheWeb you are 100% right, if anyone does this the filter need to be on the intake side of any air mover, (fan, blower, AC, heater, ect) there is a few reason why: 1 yes it helps keep the equipment clean. 2 a filter creates resistance (slows down) in the air flow, thus would create preasure inside of it, that could burn out the motor. however i think they did this for the video so they could get a cleaner measurment just to make their point.

[EdKLunar]

@1crazyfocker

I agree that putting the filter over the intake seems the most rational and is what i would probably do, but if I'm not mistaken, I think according to physics it doesnt matter whether the fan is experiencing air resistance because there is pressure upon pushing the air out or because there is drag upon trying to pull the air in. They both slow the fan down the same amount.

[1crazyfocker]

@EdKLunar , but its not just the drag on the blades air pressure too, its like this, when the air flow is restricked on the intake(filter), the pressure drops (less friction thus less power), and filtered cool air flows over the blades/motor cooling it better. when the air flow is restricked(filter) on the outlet the air pressure goes up (more friction more power) plus you have dirty hot air flowing around the blades and motor(trapped). thus heating it up more, and pulling more power.

[BOOSTEDLASER]

@1crazyfocker I have 2 of this style cleaner for over a year now.I use a 3m 2200 top of the line filter in front....and a cheapie "pre filter" washable mesh in back.Total cost..under 40 bucks.On my meter I reduce large parts 95% and small parts 75%.Neither lasko 9$ fan has ever overheaded or stopped working. I run them 24/7 in my shop.Air flow is less then a naked fan YES..but to get this level of filtering from a "mass MFG" purifier , I would spend 10-15x this amount.

[1crazyfocker]

@BOOSTEDLASER good for you... i never said this was a bad idea, or not to do it, i think you need to reread what i wrote. so instead of trying to pick a fight, try reading or is that to much for you, here let my bring this to a troll level for you,

Filter on front makes fan work harder and use more power and dirty, filter on back works better because fan dont use as much power and fan stays cleaner. grunt, snort, grunt, grunt!!

good bye

[pourshot]

@eliassaab1 With a front mounting, even though there is air escaping at the corners, enough positive pressure is maintained on the filter to keep a reasonable air flow through it. I got enough debris in mine that I do not have to dust near as much. It worked so well in fact that I made 2 more and have them in different parts of the house. The tape did not last long so I made brackets for the first one from mini-blind brackets that had left over. The 2 new ones I made with cheap u-channel.

[tringuyen552911]

wow this is exactly what I need. Thank you for this great yet simple idea :D

[immak4u]

at 3:20 it increase from 47600 to 52400 :P

[MegaSohip]

Wow only 4 comments, people are rich.

The surface are on a furnace filter is huge. I built this today but better ... lol used a "V" section using 2 filters . Then put another 2 low cost, high flow filters on top to protect the good ones from big crap.

Look up Squirrel blower fan hepa. Or search like that. You will see some great ideas. !!

[eliassaab1]

I thought about the idea and built three yesterday. During the evening, I thought that someone might have thought of the idea before me and after some googling I saw this video. I put mine on the back to protect the blade and the motor from dust build up and I also tied it to the filter.

You can see a picture on

saab.org/AirPurifier.jpg

[pourshot]

@eliassaab1 I thought about that myself and even called and spoke to Dr. Terrell asking him why he did not put it on the back as you did and as I thought about doing. The problem with mounting the filter on the back is you get quite a bit of air that enters around the fan blade in the front corners and exits right out.

[rlund3]

I have used this system for 10 years. It is great for saw dust also. In 10 years it has not overheated the motor. For sawdust I use 2 filters. a low merv for the coarse particles and a higher merv a

[HarryTrumansGhost]

Great idea Doc! I'm jealous I didn't think of it myself. Thank you.!

[VAGunNews]

Hey Doc, why not put the filter on the back of the fan so only clean air is crossing the fan blades and motor just like a home heat-pump air handler? Also, the negative pressure would help hold the filter in place.

Related questions:

Is there a more efficient speed for the fan to remain at?

and

Does the dense filter increase the motor temperature enough to be concerned about a fire with the filter (flammable filter?) that close?