[–] ChaoticNeutral 0 points 39 points (+39|-0) ago 

HEPA filters do, they work on the same principle your coffee filter does. However, you need enough air exchanges of the environment to make a difference. Too few air changes, more crap in the air.

Electrostatic filters are snake oil except for for tiny confined spaces.

I work in and spec out clean rooms.

[–] voatusernamevoat 0 points 11 points (+11|-0) ago 

HEPA filters + indoor plants known for sucking up dust. https://www.hunker.com/13411850/indoor-plants-that-reduce-dust

[–] VoataoV 0 points 0 points (+0|-0) ago 

Nah the NASA experiments, while showing plants do filter air, are misunderstood and you need a ton of plants in a small space to see any substantial results.

[–] Putzmiester 0 points 1 points (+1|-0) ago 

Quality engineer for semi conductor manufacture here. What this guy said. Just gotta add, HEPA filter life is shit, you will only get a fraction of the performance out of a new one as an old one.

Clean rooms often use ultra vacuum pumps, cryopumps and turbo molecular pumps to achieve their cleanliness, not exclusively a filter recirculating air.

[–] illuminalto2 0 points 0 points (+0|-0) ago 

Hello /u/ChaoticNeutral ! I'm IT person and am just replying to save your name so that sometime in the future I can pester you with questions about clean rooms in case I need to build one.

Reply "FUCK YOU" if this is not okay and you hate my face.


[–] ruck_feddit 1 points 12 points (+13|-1) ago 

I very recently built an air filter out of a regular box fan. I got the idea when I saw how expensive a replacement filter is for a proper one when compared to a 20"x20" HEPA furnace filter. Come to find out, there are of course people already doing it on YouTube.

I bought a cheapy 20x20 filter for the back and the best 20x20 HEPA they had at the store for the front. The fan was new and usually powers this big tent thing the kids play in. Not counting a fan (and duct tape) we all likely own anyway, I'm out about $20.

I don't have any fancy meters or anything, but I have noticed a major reduction in airborne particulates visible in a flashlight/laserbeam in the dark. This is especially true after running in a bedroom overnight, but the same is true with it running in the main living area. There is also a carbon element to the HEPA filter, and I can tell you this part works as advertised.

I imagine the airflow with filters is still greater than a typical air filter. The fan noise is greatly reduced. It will still blow out a lighter from 10" away. After a week, there is a circle on the intake filter that is visibly darker than the rest, so I know at least that part is working, too.

I was about to hit submit when I saw @carlip linked one of the videos.

[–] KILLtheRATS 0 points 1 points (+1|-0) ago 

This works. That's the setup I have now. I'm going to make a wood enclosure that I can slide filters into. I have a 4" inline fan to suck the air trough it. I'm going to put it on my basement floor and pipe it in to an existing air register in the upper floor. That way the cold air that settles in the basement can be recirculated to cool the upstairs. I did a version on it last summer and it helped

[–] ruck_feddit 0 points 0 points (+0|-0) ago 

Now you're talking! I told the wife I wanted to build a box with a filter on each outer side. A high CFM 6" or 8" inline fan (not a wimpy duct booster fan) could sit right on top and push air into the box. 4 filters would greatly reduced the CFM drop.

Doing it your way, I would pull the air into the box through the filters, up through the fan, and into the upstairs. I have all the hardware I need to tie into my ducts. I didn't think of the tying it into the upstairs part. I like it.

[–] TheTrigger 0 points 1 points (+1|-0) ago  (edited ago)

What type of fan did you buy, can you link to a reference picture so I have an idea? Very interested in building one of these. Might even do it tomorrow; been thinking of buying a good air purifier, but those things are way too expensive, for what they do, and would have to buy too many of them to cover the whole square-footage.

[–] ruck_feddit 1 points 5 points (+6|-1) ago 

I had a standard box fan already. They're all a 20" fan and $15-$30 online or in a store. 3 speed dial on the top, little feet things on the nice ones so they don't fall over. A 20" x 20" furnace filter covers the entire front/rear perfectly. The only reason I put a $2 filter on the rear was to keep the more expensive HEPA filter on the front cleaner for longer.

In any other moving air project of mine, I treat air like a chain. Typically, air/chains are pulled a lot better than they are pushed. In this setup though, air is pushed through the filter. If I weren't prefiltering the air, I'd put the HEPA on the rear (intake) of the fan.

You want a picture?

[–] carlip 0 points 7 points (+7|-0) ago 


Do this and let me know if it's legit, thanks.

[–] ruck_feddit 0 points 2 points (+2|-0) ago 

I pinged you in my original post. I built one of these last weekend. I don't have fancy equipment to test my air, but I think it's working as intended. I used a front and rear filter unlike most on YouTube.

[–] lbruiser 0 points 0 points (+0|-0) ago 

Would the rear filter reduce the air flow through the filters effectively reducing how many particulates go through the filter?

[–] Drenki 0 points 5 points (+5|-0) ago  (edited ago)

be careful with electrostatic devices because some will generate ozone, which will then oxidize almost whatever it comes in contact with, including your lung tissue.

[–] goship 0 points 1 points (+1|-0) ago 

so is it healthy to run this "Ion" option that exists e.g. on various humidifiers? Do you have a technical/medical background or is that your personal opinion?

[–] ChaoticNeutral 0 points 2 points (+2|-0) ago 

I have a PhD in Physical Chemistry. Ozone is very bad for you to breathe, once it starts to ‘smell like a thunderstorm’ you’ve inhaled too much. I love that so many of those things use that phrase in their ads as if it’s a good thing.

[–] Drenki 0 points 1 points (+1|-0) ago 

I had a Winix plasmawave air filter and a bunch of rubberized stuff in my house started corroding and falling apart after about a year.

If it produces ozone, that's bad, but you'd have to measure it for yourself

[–] AmaleksHairyAss 0 points 0 points (+0|-0) ago 

Information about what ozone is and does is widely available.

[–] Buff_Awesome 0 points 4 points (+4|-0) ago 

Don't forget to have a control room in addition to your testing room. It'd be ideal if you could compare two rooms of equal air composition, like two bedrooms or two bathrooms (if you have that many).

[–] ElDulce 0 points 4 points (+4|-0) ago 

I live in SE Asia. When I first moved to the country I'm living in, after about a month I started getting this weird cough. Like when you are on the edge of being sick and you can feel it in your chest. I didn't know what was causing it, but I knew that this part of asia has really crappy air, so I got bored and built myself an airfilter that could use the honeywell R3 airfilters. The cough went away within a month. I've run out of filters twice since then (I have to order hepa filters from the states) and each time the same cough came back. I currently have 4 other friends with the same cough. I'm trying to get them to also get a filter so I can see if it's not just in my head, but from what I've seen they work.

[–] NiggerVirus [S] 0 points 3 points (+3|-0) ago 

I've heard Asia has some disgusting air

[–] ElDulce 0 points 5 points (+5|-0) ago 

It does indeed. Some of it's from burning jungle so corporations can plant oil palm, some of it is from burning off rice patties at the end of a growing season, some of it's from the factories and some of it is from a whole lot of noone-gives-a-fuck. It gets a bit better up in the mountains above Thailand and in Myanmar, but it starts getting bad around from Bangkok down to Singapore and of course anywhere remotely close to China (Vietnam and down).

[–] scandalous-goat 0 points 4 points (+4|-0) ago 

The machine may be too small to have an effect. But I'm still curious about the result.

[–] NiggerVirus [S] 0 points 2 points (+2|-0) ago 

As far as these machines go it's one of the best and biggest ones you can buy. Over $500

[–] MarauderShields 0 points 2 points (+2|-0) ago 

I live in polluted environment, outside AQI regularly above 100, sometimes +150. Indoor filtration is a godsend for our family. We also use a Laser Egg to monitor, along with the website <<waqi.info>>

Been using Honeywell for the filter which is awesome, but the Laser Egg sucks balls. There must be better alternatives.

Also use heavy ozone treatment for mold twice a week or so, but that's less practical as you have to vacate the house while it's going on if you're open plan like we are.

[–] NiggerVirus [S] 0 points 1 points (+1|-0) ago 

The filter I have filters and used electrostatic ionization. I should receive my monitor today.

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