$50 Air Purifier

[Northern Lawn]

Rather than replace the very expensive filters for my Sharp air purifier I followed instructions and made one for less than about $50.

All you need is a 20 inch box fan and two furnace filters. Tape a large particle furnace filter and a 3M filter on the front. I used a furnace filter rated at 2200 or 94% efficiency. Supposedly this sit up will do the same job as a thousand dollar air purifier.


I basically followed this guys video.

http://www.youtube.com/watch?v=JnifYrtPUrA

 

[lxskllr]

I've told other people that idea, but never used it myself. It should work pretty well, especially for large particles like pollen, but nobody has tried it out. I don't know why I bother talking sometimes :^/

 

[Northern Lawn]

Mine is working fine though I cannot tell how clean the air is as I don't have a quality meter. Blows LOTS of air on 3 but a little loud speed one is fine. I'm only worried about the electric engine getting warm but the guy in the video had his running for over a year without issue and he has a air quality meter.

 

[The_Dude8]

won't the fan make a lot of noise?
what kind of fan did you get from hd?

 

[ManBearPig]

deleted

 

[Tiamat]

Rather than replace the very expensive filters for my Sharp air purifier I followed instructions and made one for less than about $50.

All you need is a 20 inch box fan and two furnace filters. Tape a large particle furnace filter and a 3M filter on the front. I used a furnace filter rated at 2200 or 94% efficiency. Supposedly this sit up will do the same job as a thousand dollar air purifier.


I basically followed this guys video.

http://www.youtube.com/watch?v=JnifYrtPUrA

That idea is fine but the filters might be dropping your exchange rate so low that it doesn't appropriately cycle the air. The best spot to place these contraptions is placing the inlet 1/3 of the long wall hanging from the ceiling close to that wall assuming a rectangular room. This location grants an opportunity to get the air in the room to circulate most efficiently without odd blockages.

A better contraption is to use the squirrel cage HVAC furnace fans that HVAC contractors might be throwing away. This design is used by the air circulators selling for 500$ that are used in woodworking shops. Filters from Wynn work extremely well (the pocket ones) and they do not stifle the air flow as much. At 800 rated cfm, using my 0.5 micron dylos meter, I can watch the particle count drop from ambient to 0 in less than 1 minute in my small 1500 cuft. Workshop.

If u cannot get the squirrel cage, using multiple of your contraption should work fine as long as they are situated roughly at 1/3 dimensions for the inlets around the ceiling edges to boost each other into forcing a decent circular motion. Placing the outlet at 1/3 rather than closer to 2/3 causes the air to hit the closest corner and create turbulence rather than cyclic motion...

 

[MisterJackson]

Damn. This is so simple that I feel stupid for not thinking of it sooner.

Thanks for sharing OP!

 

[mmntech]

Been doing this for awhile. Just buy a furnace filter then cut it to size.

 

[AustinInDallas]

This is the exact same method I use to make jerkey!

 

[smullet]

I made two of these, running almost 1 year. You can make them for around $30, ~$17 Home Depot fan + ~$10 3M filter. They work pretty well. I change filter every 3-4 months, when the filter get very grey and dirty. The fan is pretty loud, even on the lowest setting, but it moves a ton of air. The contraption is not too pretty tho.

 

[TechBoyJK]

Yep.. I have a few of these setup around the house.

No way to guage how well they are working except when you can tell it's time to change the filters. But when it's time, you know they work!

 

[Northern Lawn]

It's too bad air quality meters are so expensive, I would like to be able to 'see' the job it's doing by taking measurements. I have a TDS water meter (total dissolved solids) that only cost $20, it measures parts in the millions. But the cheapest Air quality meter I could find was $200.

 

[zephyrprime]

If the flow is too restricted, you could buy 5 furnace filters and construct a box out of them and put the fan on that.

 

[Tommy2000GT]

A box fan with a furnace filter looks so redneck. Just spend the money and get a real air purifier

 

[Tiamat]

A box fan with a furnace filter looks so redneck. Just spend the money and get a real air purifier

Many of the "real" air purifiers are garbage. Honeywell and iqair make one of the best in their respective price ranges, but cost quite a bit more than the box fan idea with the HEPA cylindrical Honeywell at about $150 and iqair at $900.

 

[slightlyhuman]

A box fan with a furnace filter looks so redneck. Just spend the money and get a real air purifier

LOL.

so you would rather pay $200 + more for looks?

go ahead. :biggrin:

 

[Northern Lawn]

It's the new filters for air purifiers that screw you. It's like Ink for printers, they way way over charge.

So you redneck furnace filters that do just a good a job and only cost a few dollars.

 

[Jon-T]

Not a fan of this setup.

When my Hunter "lifetime" filter needed replaced at $$$ I bought some MERV13 (highest I could find) air filters that fit right in. They never impressed me. If I shined a high power flashlight back and forth I could see the beam. Not just some large dust particles, there was a very light glow to the air from some microscopic stuff.

Last month I saw some Honeywell electrostatic machines for a good price on Amazon. I was always skeptical of the electrostatic machines, but, I went for it. The air just seems cleaner and if I shine the flashlight the beam doesn't stand out like it used to.

I wish I would have gone for a Sharp plasmacluster machine years ago.

 

[Leros]

I'd rather put something more attractive in my house, but I've thought about using something like that in my garage to filter out wood dust from the air.

 

[Northern Lawn]

Not a fan of this setup.

When my Hunter "lifetime" filter needed replaced at $$$ I bought some MERV13 (highest I could find) air filters that fit right in. They never impressed me. If I shined a high power flashlight back and forth I could see the beam. Not just some large dust particles, there was a very light glow to the air from some microscopic stuff.

Last month I saw some Honeywell electrostatic machines for a good price on Amazon. I was always skeptical of the electrostatic machines, but, I went for it. The air just seems cleaner and if I shine the flashlight the beam doesn't stand out like it used to.

I wish I would have gone for a Sharp plasmacluster machine years ago.

I'm concerned about it as well because I don't have an air quality meter to make sure. Did you have one in your experience there?

 

[TechBoyJK]

I'm concerned about it as well because I don't have an air quality meter to make sure. Did you have one in your experience there?

I have two cats in the house, and if I let one run 4-6 hours a day, the filters need to be changed after about 3 months. So I know they are certainly picking up stuff.