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An Affordable Air Purifier For Dusty Computer Labs?

Alcimedes writes "Our lab has a serious issue with dust. I've had a number of power supplies stop working because of dust clogging up the fans, and it's getting annoying. So I'm looking into some kind of small (under $500) air filtration system, and was wondering if anyone else out there has already gone down this road. If so, what did you buy and would you buy it again? I'd prefer something where I don't have to keep buying filters, but that may just be a pipe dream." Anyone with cats knows the feeling. Can you suggest a reasonably priced answer to dust-borne failure?

44 of 552 comments (clear)

  1. air purifier by Anonymous Coward · · Score: 5, Informative

    despite the hype, the sharper image "ionic breeze" actually collects a lot of dust, and doesn't require replacement filters. I have one near my computer at my house, and it definitely collects a lot of dust.

    1. Re:air purifier by Anonymous Coward · · Score: 2, Informative

      thats funny, I've got an 'ionic breeze" next to my computer to, and my computer collects a lot of dust!

    2. Re:air purifier by spike2131 · · Score: 5, Informative

      I bought a product very similar to the iconic breeze, and it does wonders to cut down on dust in our home. The one I have is called the Gerry Air Purifier. That's "Gerry", as in the baby products company. It was marketed to be put in a nursery to filter air for newborns, but it works just the same as the one for adults, at a lower price.

      I didn't get it at Sharper Image, though, it was on special at Wal-Mart.

      --
      SpyDock: Scientific Python in a Docker container
    3. Re:air purifier by Monkelectric · · Score: 4, Informative
      Completley wrong my good sir. Consumer Reports tested the ionic breeze and *was unable* to measure its effectivness because its filtration was "below measurable levels" if it was doing anything at all.

      That being said the ionic breeze uses the *best* technology for air cleaning, but the lack of a fan makes it completley useless. There are other models out there that use the same technology and have fans.

      I would recommend spending the 5$ or so to get a copy of the air filters report from http://www.consumerreports.org (no I don't work for them, I'm just a fan:) (I seem to have lost my print copy of the article otherwise I'd tell you the recommendations). If you aren't familiar with consumer reports, basically they are a non-profit who buys everything from spackle compount to cars and tests it rigorously using the scientific method. Their reports include an overview of the different technologies involved, overview of pro's and cons, and a discussion of what devices are suited for what applications, and finally their *scientific* tests of the devices and their results. Devices are then ranked by overall score in each category measured (some categories can be objective like "ease of use"). In the case of air purifiers they put each purifer in a chamber with a known quantity of (measureable) debris, and after a ceartin period of time they saw how much/little was left.

      --

      Religion is a gateway psychosis. -- Dave Foley

    4. Re:air purifier by GreatOgre · · Score: 2, Informative

      So did they just put them in a chamber with no movement whatsoever? The way I understand how the ionic breeze works is that uses the air flow already in the house so as not to require fans which are noisy.

      Now, you may say that the air in your house is still. Not so, the air just moves sooooooo slow that it feels still to use.

      But overall, I would say that unless their chamber had some air flow, it was not a very scientific test. Now, if they used several different air velocities during the tests, then they may have a point. Might have to scrounge up a copy of that report at the local library to find out for myself.

    5. Re:air purifier by Anonymous Coward · · Score: 1, Informative

      Honeywell sells two models similar to the ionic breeze but with a fan through Radio Shack.

    6. Re:air purifier by cornjchob · · Score: 4, Informative

      No measurable levels of filtration?

      No effin' way.

      I'm in highschool, and my English teacher has an Ionic Breeze in his class--I have absolutely horrendous allergies and sinus problems, but as soon as I set foot in his class, it's beautiful. My sinuses clear up and I can breathe; it's incredible. And I was very skeptical at first (I mean, how seriously can one take those god awful commercials?), but when I took his apart to see the plates--man, just caked with dust. These things work, make no doubt about it.

      And there doesn't need to be a fan--the difference in charge pulls the air. It's actual physics, and it definately works. Take a plastic spoon and rub it a bunch of times against wool. Then, go to your nearest sink and turn on the water so that you have a nice, smooth flow. Hold the spoon next to the water, and it bends near the spoon. Same principal.

      --
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    7. Re:air purifier by Hodr · · Score: 2, Informative

      Most of the "Effect" of the Ionic Breeze is actually the creation of ozone which makes the air "smell" fresh but actually does little to cleanse it.

      Try looking at any online opinion site (like epinions.com for example) and in nearly every case long time users of this product say its so inefficient that dust actually settles on and around it.

    8. Re:air purifier by Monkelectric · · Score: 4, Informative
      I'll reply to you since you were the only one who was polite :) There are two measurements of efficency for air filtersm;the percent debries removed and "Air exchanges per hour". An Air Exchange/hr is exactly what it sounds like -- the entire volume of air in the room must pass through the unit in one hour. The percent debris removed by electrostatic filters is *VERY* high, however, it makes no difference if no air reaches the filter to be cleaned. The HEPA standard is 6 ae/h (i'll abreviate from now on), and some high end models achieve 15 ae/h. The problem is of course the ionic breeze *ISN'T MOVING AIR*, and thus is hopelessy inefficent.

      Suppose for a moment you are correct and the ionic breeze does recieve some benfit from the normal movements of air in the house. There is no way that it could achieve the necessary 6 ae/h, and If thats not important to you -- you still must agree that a filter *with* a fan is almost infintley more efficent :) How many cubic meters of air do you think pass through an ionic breeze due to normal house currents? My 70$ honeywell moves 5000cubic feet of air per hour.

      Sharper image is selling the same old snake oil, and the people who attacked me are pretty much defending their shiny 500$ pieces of crap, and that saddens me :)

      --

      Religion is a gateway psychosis. -- Dave Foley

    9. Re:air purifier by ndogg · · Score: 3, Informative

      I won't don't that it works well, but have you used other products of this type to be able to compare?

      Perhaps the Ionic Breeze works well, but perhaps there are other filters that work many times better, and that's why CR rated the Ionic Breeze as poor.

      --
      // file: mice.h
      #include "frickin_lasers.h"
    10. Re:air purifier by Anonymous Coward · · Score: 1, Informative

      Ozone does clean air, it oxidizes impurities, killing germs and removing smells...

    11. Re:air purifier by Lord+Prox · · Score: 4, Informative

      I have had a major problem with dust in the air at my place. A new shopping mall is going in back of my place and the construction is hell. Earth movers, graters, if it's big n yellow is there. I finally got pissed and did something...

      1 Old cardboard box
      3 scrap box fans
      1 "filtree" by 3M furnace filter.

      Blend with duct tape and let simmer for 24 hours over lo heat and volia! Big reduction in dust

      Best of all clean up was a snap! The whole damn thing cost me less that 5 bucks so I just tosses it when I was done. With a little more work you could build a larger, more permanate version. Not a $500 ionizer (I have a good idea of what is in there and it ain't 500 bucks worth. More like 10-20, but you know market forces good marketing, what have you.)

    12. Re:air purifier by HamNRye · · Score: 3, Informative

      It is about volume of air cleaned per second. I work in Air Filtration so hear me out. There are many similar air cleaners out there that use the same technology as the Ionic breeze. If they have a fan that pushes 265 CFpm through a filter, it will clean more air than a fanless model that pulls 20 CFpm through.

      The Ionic breeze works fine as long as you have something else circulating air, such as a ducting system or human movement. The way most of these filtration methods are tested is by placing them in a sealed container, and measuring how quickly they remove contaminate. That is one of the reasons fanless systems perform very poorly in the lab. That being said, it would most likely be perfect for a computer room that has tons of fans going.

      A far cheaper, and easier method is to go to your local air filter supplier, and get polyester filter material. We use BT1 (Blue Tint, 1" thick) and cover the grills of our intake fans. The stuff is incredibly cheap, does not overly restrict air flow, and will get most large contaminates out of the air. (> 1 micron). You can get a 20'x20' roll here for about 2 bucks.

      If you are interested in a system like the Ionic Breeze, try a Trion air cleaner. It uses the same electrostatic plates, but has a pre-filer that catches larger contaminate making the plates more effective (because they are working with smaller contaminate) and reduces the cleaning frequency. These are also fan driven models that will clean a larger amount of CFpm. They are generally $100-$200 cheaper than the Sharper Image product and can be found at Sears. However, electrostatic plates are generally designed to work with extremely small contaminate particles like smoke. I would assume that most computer rooms are worried about dust which is a 5 micron or greater particle. The poly pre-filters in front of intake fans shoud work best in these situations.

      Basic Air Filtration:

      1 Box Fan
      1 Roll BT1

      Cover the intake of the fan with BT1. Run fan.
      This Filtration system should run about $15. Get a fan with a high enough CFM rating that it will circulate the air in your computer room 2-3 times per hour. Change filter monthly.

      For an upgrade, get a pleated filter and a bigger fan. Pleated filters will reduce airflow by 10-15%, figure that into your CFM calculations. Pleated filters are also far more efficient.

      PDF on trion air cleaners: http://www.trioninc.com/pdfs/residential/02-0251.p df
      (Also has a diagram of how an electrostatic air cleaner works. ala Ionic Breeze)

      One final note: Do not use Ozone Generators. They don't get large particles, only smaller ones, and they are potentially dangerous.

    13. Re:air purifier by instarx · · Score: 2, Informative
      OK, I am what you are calling a HEPA engineer, although there really is no such thing. I have had some backbreaking aerosol physics and ventilation design courses in graduate school and designed and tested clean rooms for years. Here are some facts you should consider...


      The ionic cleaner works by producing charged ions and releasing them into the room. The theory is that dust particles attach themselves to these charged ions and are then attracted to surfaces such as walls and floors (and, I guess, computers and electronics). It is the number of ions released to attach themselves to particles that makes the ionic cleaners work, not the amount of air that passees through them. Some ionic cleaners have an oppositely charged plate that helps collect the charged particles, but mainly the particles get collected on walls. The mistake everyone is making is in thinking that ionic cleaners filter air when they do not - they just release ions. You do not need a large airflow to release zillions of ions.


      Air filtration systems on the other hand rely directly on the amount of air passing through them and the efficiency of the filter. To determine the efficiency of a filter you must define the particle size. A chickenwire filter is 100% efficient for tennis balls, but lousy for dust. A HEPA filter is by the way, 99.98% efficient for particles >=.03 microns.

      Air chages per hour is a particularly bad way to judge the efficiency of a filtering system. Air changes per hour is really a term of art used in the ventilation trades as a yardstick to meet general ventilation standards for different room types. One air change per hour does NOT mean that all the air is changed in the room every hour. Most people think that a filter passing 5000 cubic feet of air per hour will filter all the air in a 5000 ft3 room in one hour. Not so. Because the clean air is constantly mixing with the dirty unfiltered air you are essentially cleaning the same clean air over and over again. Therefore it takes a lot longer to pass all the dirty air through the filter. I could give the equation, but a good rule of thumb is 7 times the volume of the room in acph to filter 99% of the air at least once. In other words a 5000 ft3 room will need a filtering system cleaning 35,000 ft3 of air per hour. That isn't really that hard - only ~500 ft3/minute. BUt who says you need to filter all the air every hour? Put another way, a filter with a Q (flow rate) equivalent to 1 ac/h (5000cfm) will take about 7 hours to filter all the air in the 5000 cf room. Because it is a logarithmic function you get about 85% filtering in 4 hours.

      A big difference in ionic cleaners and filters is that ionic filters do best with very small particles while filters do best with larger particles. An ionic cleaner will remove many more particles than will a filter because it is easier to get a higher charge/mass ratio in small particles, but the filter will likely remove much more mass from the air. (Small particles don't weigh much).

      The best and cheapest thing for the original poster to do is to buy a floor fan or two and put some cheap trimable filtering material on the upstream side of the blades. Air conditioner foam filters for example. The pressure difference should be enough to hold it in place.

    14. Re:air purifier by Ronin+Developer · · Score: 3, Informative

      Ummmm...I would recommend that. The Ionic breeze works on the principle of charging dust particles and then attracting them to an oppositely charged plate. Some of the ionized particles get through. I'd have to think that injecting ionized air into your PC is not a wise idea. I'd have to question whether having them in the same room as your ocmputer equipment is a bright idea either.

      As for the guy who says that Ionic Breeze doesn't work isn't familiar enough with the technology. Electrostatic air filters have been in effect for years with forced air systems. However, with proper design it can charge air/dust particles and accellerate them out the other side. I did something similar as part of my ionic engine science fair experiment in 1982 (I used a 200,000 volt differential and iodine gase as my propellent). Worked quite well.

      What nobody is discussing is that these systems generate low to moderate amounts of ozone. While it's great to have in the upper atmosphere, ozone in your breathing air is quite corrosive to your lungs. If you suffer from ashma, I'd go with a filtration unit over an air ionizer.

      RD

  2. Sharper Image by BrianGa · · Score: 3, Informative

    The Ionic Breeze gets wonderful reviews. A friend of mine uses one in the house. I'm sure a few of them strategically placed could help your dust situation...no filters or bags to be replaced, so minimal upkeep. Link to follow: http://www.sharperimage.com/us/en/catalog/productv iew.jhtml?pid=175000&pcatid=1&catid=101

  3. HEPA filters by Zugok · · Score: 4, Informative

    That's what you need. I work in a cleanroom making IV infusions and we have HEPA filters in the ceilings of the clean rooms. Of course we have HEPA filters else where as well, but it start with the room. That's the expensive option. The next best would be a Dyson vaccum cleaner with a HEPA filter to really suck up all the dust out of your lab.

    --
    "I just can't sit while people are saying nonsense in a meeting without saying it's nonsense" J Watson, Sci Am 288:(4)51
  4. Common sense helps by cpct0 · · Score: 5, Informative

    There are a few air purifier that might do the trick for not a lot of money. I'd say the few parts you should first look at is WHERE does the dust comes from.

    If it's airborne, air purifier.

    If it's more like cat hairs (like in my house) simply elevate your computer from the floor. 1ft high and you will get 1/8th the dust you used to have.

    If it falls from everywhere, put your computer under something... and a good paint job can help too.

    I know it's all common sense, but usually you can remove most of your problems with common sense.

    Have a nice evening
    Mike

  5. PMS by StikyPad · · Score: 5, Informative

    The military's solution is called Preventive Maintenance (or PMs for short - yes, it's real). It basically boils down to wiping off the dust on a regular basis, just like you would with the rest of your house. It's not fun, but it works, and it's well under $500.

  6. Re:Radioshack has something, and it actually works by Sponge! · · Score: 5, Informative
    --
    Sponge!
  7. HEPA filter by afidel · · Score: 2, Informative

    Get a HEPA filter with a washable dust prefilter. Walmart sells several and you can get them rated for 20X20 foot rooms for $200, if your room is bigger then get two and set aside whatever is left over for replacement filters. Plus if your environment is that bad you should be cleaning the area for the workers sake, equipment is cheap to replace, sick or disgusted workers are not.

    --
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  8. Panasonic for room air filters by cporter · · Score: 3, Informative
    Panasonic makes some small, effective air purifiers that have filters for odor as well as small particles down to 0.3 microns. I bought the F-P20HU1 for 600 sq ft apartment. Not sure about dust but it's great for seasonal allergies and kitchen odors. Panasonic claims life of 1 yr for odor filters and 3 years for HEPA.

    They're only about 6" deep with a front intake and top exhaust so you can push them right against the wall.

    List prices in the $199 - $239 range. Check out appliances.com or even better, Froogle for retail pricing.

  9. Particle Size by jbyron · · Score: 2, Informative

    HEPA filters are great for removing very small particles (like pollen) but they don't do anything for larger crudites. Hair and other dust settles so quickly that a HEPA wont get it unless the wind speed in your room is over 40 mph. And most HEPAs are rather noisy. For cat hair, a simple fiberglass filter near the computer will work fine. And a vacuum cleaner.

  10. Electrostatic Air Filtration by MBCook · · Score: 5, Informative
    I would think that a form of electrostatic air filtration would do the best job. Sharper Image has two or three (here, or here) would be the kind of thing your after. There are different sizes, etc, but this is probably the best thing you can get. On top of this, you might want to invest in some of those fan filter covers for computer fans that are made of fabric or whatever to keep dust out. There are some here, here, and here. I would think that the combination of these things would keep you pretty low on dust. That said, make sure to clean the air purifier and check the fan filters every once in a while to make sure they're clear or else thing might end up worse than before. Once the room is clean (after the first week or whatever) and you've cleaned everything out, I'd imagine that you'd wouldn't have to check the fan filters much at all (maybe only when working on that specific PC) as long as you keep the electrostatic air filter going on clean.

    Also, see if you can talk to whoever in incharge of the heating/AC system in the building to see if there is anything they can do. Maybe Allergy Free has a filter that would work with the system or maybe you could get together the with the other groups of people in the building and buy an electrostatic air filtration system for the whole building. They work great on both dust and allergies. These are just wild ideas from brainstorming, they really aren't that realistic I guess. The first paragraph though will probably work well.

    PS: We have electrostatic air filters installed in our house. We also had them installed in the house we had before this one. Our family has allergy problems and when we clean them, you'd be amazed the colors the water turns from what comes off them. They really do catch alot.

    PPS: Or you could just watercool everything and run it all through one massive radiator. But this would be a bit more than $500. More pipedreaming.

    --
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  11. Re:Sharper Image ("Wonderful Reviews"???) by logullo · · Score: 5, Informative

    IIRC, Consumer Reports gave the Sharper Image Ionic Breeze a hefty thumbs-down.

    You might look at air cleaners of the type used in woodworking shops... they'd be a bit louder than the Ionic Breeze (understatement), but they'd actually do something useful for the money spent.

  12. Radio Shack vs Sharper Image by fliptout · · Score: 5, Informative

    Yes, the Environizer sold by Radio Shack(made by Honeywell) is a pretty good product. There are two huge differences between the two air purifiers sold by RS and Sharper Image: 1. The Honeywell Environizers have a silent fan built in; the SI product does not. Having a fan means you can clean a much larger volume of air. 2. Price. RS has much lower prices, at least $100 less than the competition for a comparable product.

    I love my Environizer and recommend it to everyone who wants cleaner air.

    --
    A witty saying proves you are wittier than the next guy.
  13. A Friedrich C-90A is your best bet by Anonymous Coward · · Score: 2, Informative

    At $499 it is just barely in your price range, but it is one of the top-rated small air cleaners. It is electrostatic like the Sharper Image model, but includes a large fan to move air over the plates, making in much more effective for a lab environment. I believe that it is rated for an area of up to roughly 500 square feet. You can just throw the electrostatic plates in the dishwasher once every couple of months, and you really don't need to replace the charcoal filters unless you are trying to remove odors. I have been using one for 6 months and am very happy with it. The downside is that it is very ugly-- looks like medium-sized pet carrier.

  14. FIltration by SeanTobin · · Score: 2, Informative

    This may sound a bit odd, but I've done it on a few computers (where the case permits) with abnormally good results.

    Take a coffe filter, cut to size, and tape it infront of/behind all the air inlets to your case. Even after a year of sitting on carpet in a dusty area, the interrior was devoid of fuzz and dust pup^H^H^H bunnies.

    Now, the last time I did this was in the pentium 133 area... Be sure to monitor processor temperatures for a few days to make sure you are getting adequate cooling.

    --
    Karma: SELECT `karma` FROM `users` WHERE `userid`=138474;
  15. Air Filtration by Sooner+Boomer · · Score: 5, Informative

    Don't know exactly how your computer room is set up, but here's what I did. There are two basic types of "filters" - mechanical and electrostatic. The mechanical filters work by trapping the dirt onto the filter. Throw away the filter, throw away the dirt. The electrostatic filters work by placing a charge on the dust particle. The particle is then attracted onto a nearby surface. This nearby surface may be part of the filter element (like with a permenantly-charged electret filter or a powered electrostatic filter), or it may get stuck to a nearby wall, ceiling, or piece of furniture. This is what happens with a lot of the "ionic" filters. The dust is out of the air, but it's not really removed from the environment. What I have on my central AC unit is a disposable pre-filter (like a conventional AC filter), a high-capacity HEPA filter (a cartridge that looks like a bunch of folded-up paper towels), and a powered electrostatic filter. I change the pre-filters monthly (they're cheap), change the HEPA filters once a year, and wash out the electrostatic element every 3-6 months. This keeps my computer and other electronics fairly clean, even with multiple cats. One way to tell is by the amount of stuff that gets attracted to the TV screen; not much. The only disadvantage to a powered electrostatic filter is the possibility of the creation of ozone.

    --
    Chaos maximizes locally around me.
  16. Re:Slightly off topic by CliffH · · Score: 2, Informative

    I've built plenty of rackmount systems with filters in place (cloth and wiremesh). It's a pretty common thing for servers and wonder why it hasn't caught on for workstations and home systems yet. I'm sure the cases are out there with the filtering on them, I jsut haven't had a look for any yet. If anyone is going to have them though, check out Lian Li, Procase, Saturn, Enlight, Inwin, or just do a general search. WHat you're probably looking for is something with a removable, reusable filter. DO a goole search and I'm sure you'll find what you're looking for on the cheap (ie. stay away from Lian Li for cheap). Otherwise, nice lil DIY project if you have some time, patience, and a spare case you don't mind butchering.

    Cliff

    --
    sigs are like a box of chocolates, they all suck remove the underscores to email me
  17. Try a pressurising fan by ColaMan · · Score: 4, Informative

    I'm not sure on your lab setup, but if the dust is *outside* the lab, try a pressurising fan setup.

    Get a 2 inch outlet cyclonic type air filter, typically used in tractors, bobcats and small motorised machinery.
    Hook it to the suction of a blower fan, outside your lab.
    Duct the exhaust of the blower *into* your lab.
    Try and close as many doors and windows as possible.

    The blower will pressurise your lab with clean air, which will try to escape out all the nooks and crannies in your lab, keeping the dust outside.

    Don't forget to check the filter every couple of weeks until you get a handle on the maintenance interval required, and don't get a cyclonic filter too big for your fan, as they need high airflow to spin out the dust particles effectively.

    This works for a coal lab of ours that is located very close to a 100,000t stockpile of loose,dusty coal. The dust is bad enough that if a blank piece of paper with a pen on it is left outside the "clean room" (still inside the building) you get a "shadow" of the pen on the paper in about 6-8 hours.

    --

    You are in a twisty maze of processor lines, all alike.
    There is a lot of hype here.
  18. Friedrich air purifier by kaybee · · Score: 5, Informative
    If you have a subscription to Consumer Reports, they did some tests of air filters. Contrary to other replies to this post, they found the Ionic Breeze to be next to useless. Maybe their test environment did not properly represent the real world, or maybe they are right. In any case, they said that the Friedrich C90A removed more dust than any other air filter that they tested. It operates with electricity like the Ionic Breeze, but has a powerful fan and more filter stages. No filters to buy, but it is definitely bigger and less attractive than the Ionic Breeze.

    Here is a link to purchase it: Friedrich C90A

    1. Re:Friedrich air purifier by sam+the+lurker · · Score: 2, Informative
      From Consumer Reports, February 2002
      You can also save the $72 annual cost of replacing the Friedrich's auxiliary carbon filter. Designed to remove odors, carbon filters have not been very effective in our tests. We found you can leave the Friedrich's original filter in place without losing cleaning performance.
  19. air filters / cleaners by mrbill · · Score: 3, Informative

    After doing extensive research on the subject, and looking at tons of stuff that was available, I ended up plunking down $250 last November on a Sharper Image Ionic Breeze, the "Compact" Quadra version.

    It hasnt completely reduced dust in our hosehold (we have unstained, un-sealed concrete floors, which are the #1 culprit, plus three cats), but its done an incredible job of keeping nicotine stains off everything in the computer room (my wife smokes). I put it next to her desk, and clean the "blades" every 3-4 days with a handi-wipe.

    Definitely worth the money, but they're not the perfect solution for everyone. I'll probably be buying a refurbished full-size version from their online store or eBay soon (I dont see paying full retail price again).

    Beware of stuff that is just negative ion/ozone generators - TOO MUCH ozone can be *really* bad for your health. The Ionic Breeze units put out a TINY amount (your laser printer, for example, probably puts out 10x as much), and the amount it puts out is well under federal health and safety standards.

  20. Re:Potential solution for many a dust-bunny host by DisKurzion · · Score: 2, Informative

    Make sure you use USED dryer sheets, or you'll find you're PC components covered in a weird film. Another plue is that it keeps your PC smelling fresh.

  21. Re:Electrostatic air cleaners are health hazards by Rob+Simpson · · Score: 2, Informative

    Actually, the article you mention suggests that they do a pretty good job - it is ozone generators that are recommended against. It does warn that "ozone generators, negative ion generators, and certain other electronic air cleaners that are not listed by the FDA, or cannot otherwise prove that their ozone emission levels are lower than 0.05 ppm, may produce levels of ozone recognized as unsafe for humans and are not recommended for use in occupied spaces because of the risk of generation of ozone"; however, that depends on the air cleaner and is probably much smaller with devices not intended to produce ozone. (Anyone know if there are any results from such tests? Consumer Reports, maybe?)

  22. HEPA vs. Ionic by rbrooks_na · · Score: 5, Informative

    HEPA filters were originally developed during World War II to prevent discharge of radioactive particles from nuclear reactor facility exhausts. They have since become a vital technology in industrial, medical, and military clean rooms and have grown in popularity for use in portable residential air cleaners. A true HEPA filter is defined as having a minimum particle removal efficiency of 99.97% for all particles of 0.3 micron diameter. The HEPA rating is determined using a test smoke with particles of 0.3 micron average diameter. To qualify as a "true" HEPA, the filter must allow no more than 3 particles out of 10,000 to penetrate the filtration media.

    Negative ion generators force high-voltage electricity to one or more needlepoints. Electricity is simply electrons in motion and since electrons repel one another, when they reach the needlepoint, they jump off and attach themselves to the molecules in the air forming negative ions. At that point the allergens and other particles are attracted to grounded surfaces where they can get rid of that extra electron, causing them to settle on , floors, furniture and other grounded surfaces, even on your bed. It's important to remember that a simple negative ion generator doesn't capture or collect the particles in the air, it simply causes them to precipitate out of the air.

    Electrostatic precipitators are used to scrub the air coming out of factories, but the same technology has grown in popularity in home ventilation systems and some room air cleaners. They are ionizers designed to charge and then collect particles from the air once they have been charged. First, the air is passed through an ionizer where the particles gain a particular charge. Then that air is passed between plates with the opposite charge that attract the charged particles. Electrostatic precipitators have one major drawback though; they rapidly loose effectiveness as dust builds up on the plates.

    They Ionic Breeze is essentially an electrostatic precipitator with no real means of circulating the air past the ionizer and then past the charged plates making it essentially useless.

    I run an Austin Air Cleaner in my computer room and it does an excellent job keeping it dust-free. The cool thing about it is that the filter needs to be changed only every 5 years and the pre-filter is vacuumable instead of replacable. I've found it to be a very cost effective cleaner compared to most HEPA-filter based air cleaners where you must change the pre-filters every three months and the HEPA filters every year.

  23. Re:Hope you use breathing masks... by neibwe · · Score: 2, Informative
    >"10 micron particles and below generally don't stay suspended in the air too long" You may have to worry about >10 micron particles. The larger sizes simply deposit at different locations.
    Size and density of particles, mist or aerosol - determines site of deposition. Maximum alveolar deposition at 1-5 micron size. Airway deposition 5-10 micron; nose 20 micron; fume 0.2 micron - not deposited (e.g. metal fume fever)[1]
    Smaller particles stay aloft a longer --not shorter-- period. Maybe that's why fresh outside air is suggested when a workplace has been contaminated by silicates or asbestos fibers?
    The first is that large particles tend to settle out of the air more rapidly than do small ones. The settling rate for sub-micron particles is so slow as to be inconsequential. These particles stay suspended in air and drift with ambient air currents. A 0.01 microns particle will sink through air at a rate of about 140 days to settle1 meter in air. A 0.1 microns particle will settle about 10 times as fast, and will require about 14 days to settle 1 meter. A 1 micron particle will require about one hour to settle 1 meter. The point is that these small particles remain in the air long enough to be inhaled, and they will remain in the air long enough to be swept around by ambient air currents.[2]
    Hope the info helps =D _____________ [1] Woolcock Institute of Medical Research. DISEASES OF THE RESPIRATORY SYSTEM NOTES from the Department of Medicine, University of Sydney [Online] citing "Chang-Yeung, M., Lam S. "Occupational Asthma". Am Rev Respir Dis. 1986. 133;686-703" [2] David Abrams, CIH. Airborne Dangers. [Online](05/01/1999)
  24. Re: CFCs and Ozone by some+guy+I+know · · Score: 2, Informative

    If you get too much ozone in your office, you could always release som CFCs, which readily break down O3 and make it harmless.

    My understanding is that the CFCs themselves do not break down ozone.
    What happens is that, in the upper atmosphere, sunlight breaks down the CFC, releasing, among other things, chlorine (the first "C" in CFC).
    The freed chlorine is what breaks down the ozone.
    In your room, the CFC is not going to break down (at least not in any measurable amount), and so will not break down the ozone.

    OTOH, dumping Chlorox in a pan might have the desired effect :) , but this can cause other problems, as chlorine is poisonous.

    --
    Those who sacrifice security to condemn liberty deserve to repeat history or something. - Benjamin Santayana
  25. Re:Electrostatic air cleaners are health hazards by tgd · · Score: 2, Informative

    That link comes up a lot when people are asking about the Ionic Breeze and the like online. FWIW, I have four of them on 24/7 in my house to manage dust and allergens until I pony up the cash to put one in the HVAC system directly.

    That article talks about air cleaners, not air filters. These are ozone generating machines you'd use if, for example, someone took an explosive dump in your car. It uses very high amounts of ozone to physically removed odors and clean the air in there.

    Ionic Breeze's are electrostatic air filters, totally different beast. An electric potential between two ionizing wires in the back and three collector rods in the front pulls air through without any noise, and the dust picks up a static charge and sticks to the collector rods. Thats it. In terms of controlling dust, one big thing that Sharper Image doesn't mention, which may counterindicate their use in a computer lab, is that if your air is fairly dry, it puts a slight static charge on every damn thing in the room. Fantastic for controlling dust, because you can just vacuum it off the couch, but you're always zapping yourself.

    Anyway, my point is, there's nothing in common between these filters and what ALA is talking about.

  26. Fans are NOT GOOD on ionic air cleaners!!! by caveat · · Score: 3, Informative

    Having a fan means you can clean a much larger volume of air.

    MORE air yes, but it's not going to be nearly so clean. Longwinded explantion that goes into theory follows:
    Ionic filters have a theoretical 100% efficiency for all particle sizes. How these ionic air filters work is an excercise left to the reader (apply - charge to incoming particles with a -1,000V grid, place a +1000V grid close by, all the ionized - charged particles stick to the + grid); there are scientific instruments to select a very specific size of dust particle that work on the same principle. Instead of two charged plates, they use a rod and sleeve electrode system with + in the center, and they have a very small exit slit at the bottom; the voltage across the rods is very carefully controlled along with the carrier gas flow rate (the dust has to be in some medium), and only one very specific size comes out the slit at the botton (+/- 1 nm). (TSI 3080 Electrostatic Classifier)

    The theoretical equation for this instrument describes the arc taken between the two electrodes for a given size particle in a given carrier gas at a given flowrate and voltage difference. The carrier flowrate is absolutely critical, a few tenths of a percent deviation will throw your size off by a few *tens* of percent. Assuming these ionic filters are going for 100% efficiency, and they aren't running some insane delta-V like -5000/+15,000, they need a fairly low flow rate to allow all the particles time to drift over to the collector (small particles won't move very fast through dense air in a relatively low electrical field - c'mon people, i know it's early, but think about it - smoke diffuses, water droplets from a spray bottle drops from the air a lot faster) - so to make my point finally, the Ionic Breeze uses the electrostatic air flow, which is actually probably a lot better than a fan-driven filter. The fanned filters can clean more air, but they're going to leave a lot of the smaller crap untouched...I actually wouldn't be surprised if a HEPA filter was actually more effective than a cheap ionic filter.

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    Facts do not cease to exist because they are ignored. - Aldous Huxley
  27. Oreck by mattfusf · · Score: 2, Informative

    Oreck (the vacuum cleaner people) sell an excellent air cleaner. I've had one for a little over a year and it is amazing what a difference it makes in my house.

    The model I have has three filters; a reusable prefilter, a metal collector, and a carbon filter. The carbon filter needs to be replaced every few months (they are fairly cheap, $20-$30). The prefilter just gets rinsed off and the metal collector is cleaned every 4 or 5 weeks. Mine has a fan with 2 or 3 speed settings, at the "normal" speed it is quiet enough to not be noticiable.

    I think there are a few new models, but they all operate similarly.

    Matt

  28. You obviously don't have one. by Otto · · Score: 2, Informative

    Look, guy, it's all well and good to believe unbiased reviews and so forth. I'm not saying that I'd consider CR a source of such, but hey, you believe what you want.

    However, that's beside the damn point here. The guy has one. He says it works for him. To tell him he's been duped when he's the one cleaning the dust off the blades every couple of days is a bit ridiclous.

    That's all people are saying. Nobody's defending a "shiny piece of crap", they're defending the guy who makes personal observations and decides for himself rather than simply believing anyone and everyone else's opinions.

    As for "not moving air", you're wrong. You're just simply wrong. They do move air, just not as quickly as one with a fan. You can hold up a piece of silk ribbon in front of one of the things and see that for yourself quite easily. Or if you prefer, blow smoke at it. That works just as well. I admit that it doesn't move 6 roomfulls of air in an hour, but then that's the whole point. Some people need air filtering, but cannot deal with noise. If you need air filtering and don't mind noise, then by all means get a fan system.

    --
    - Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
  29. good air filters, HEPA, allergies, & some myth by arete · · Score: 4, Informative
    There's only one problem that I see with your inexpensive setup - not enough fan. Although, perhaps it's enough for your situation, putting in a larger fan could make much better use of that large filter media. You didn't specify, but the fans ought to suck from the filter, so they themselves are protected, too.

    A short description on filters: There is, roughly, how many particles they catch of different sizes and how much air they attempt to filter. (Back to the ionic breeze later) In general, the latter is actually the dominant force in really helping you.

    The HEPA standard is irrelevant (and no longer current) in any case where you might be standing in the unfiltered air. It's designed to keep radioisotopes from escaping laboratories. That doesn't mean HEPA filters are bad - but the HEPA standard is tremendous overkill in terms of what's important to you. A small HEPA filter, for instance, might have filtered 99.97% of very small particles out of 10% of the room air in the time another filter would have filtered out 80% of 90% of the air. (Math: about 10% vs. 72%)

    That said, traditional furnace filters still suck :) as they barely do any filtering at all. In fact, I have a box of 20x25 for sale at http://www.xig.net/sale/ near Chicago. Filtrete is a wonderful solution that doesn't cost very much - and while the parent post mentioned this, I'm not sure they put enough emphasis on it. I ended up replacing my furnace fairly soon after moving here for other reasons, and I have a Honeywell F50 electronic filter on my furnace. It's not even a very efficient filter compared to HEPA, but it uses the gigantic fan that's on my furnance, so in the end, it's better.

    There is a basic difference between electronic and physical media filters that _in general_ means electronic filters work better on smaller particles and media works better on big ones. The ideal solution typically is to put a large media filter in front of the electronic air filter - which is exactly what my F50 does. (There's a washable metal mesh filter) I believe this is the nature of the Ionic Breeze controversy - that it is ineffective on industrial debris in the air, but effective at pulling out allergen-sized particles. (Yes, allergens come in many sizes. But they're all pretty small. And, you're probably not allergic to dust mites, but to dust mite FECES - just in case you weren't sure it was tiny) I certainly think a fan might help it, but in my bedroom, for instance, it probably wouldn't matter because there's a ceiling fan and quite a bit of airflow (partially from ~ 12 case fans so it varies depending on exactly where...) My supposition is that it was designed with some sort of "average" room air circulation in mind.

    If your goal involves making it easier for someone to breathe, make sure you catch those pretty small particles - Filtrete at least, electronic ideally. If you have allergies, there are lots of other things that help tremendously - like (now NOT just plastic!) covers on your mattress, hardwood floors, washing bedding in hot water... (Perhaps I'll turn this page into a webpage. Heh. I'm happy to answer questions, though, in the meantime. If I do, it'll appear at http://www.xig.net/allergy

    Disclaimers and notes: I have a degree in Mechanical Engineering, I don't have an Ionic Breeze (they cost HOW much?), nor have I read the relevant Consumer Reports articles. I do think CR usually does great work, and I purchased my washer, dryer, and dishwasher from their reviews, but anyone can make a mistake. I do have pervasive airborne allergies, and have made a great many modifications to my surroundings to improve them.

    --
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