IQAir New Edition GC MultiGas Air Purifier Oreck OptiMax Whole Room Air Purifier Cleaner Filter HEPA ENERGY STAR Commercial Ozone Generator 3500mg Industrial O3 Air Purifier Black Deodorizer... New Blueair 403 HEPA Silent Cleaner Air Allergen Purifier System Particles,Free Honeywell ENVIRACAIRE Round Portable 390 sq ft True HEPA Air Purifier 50250-S A2Z Ozone Aqua 6 Multi Purpose Ozone Generator Air Cleaner Purifier 15 Function VonHaus True HEPA Filter Air Purifier True Cleaner Ioniser Remote Control Silver Austin Healthmate Jr. HEPA Air Purifier Silver Clean Air Fights Allergy Asthma Classic Black Car Air Purifier Cleaner Ionic UV HEPA Ionizer Fresh Ozone UR New, Honeywell 50250-S 99.97% Pure HEPA Round Air Purifier, Free Shipping BlueAir 205C HEPA Home Air Purifier Blue Air FREE SHIPPING Air Cleaner Purifier Office Room Ionizer Ionic Hepa Fresh Filter Ozone Generator No Filter Air Ionizer Purifier Sanitizer Cleaner Ionic Ozone Generator Freshener

Living Air BREEZE Air Purifier/Cleaner Ozone Generator/Ionizer EcoQuest Honeywell HPA300 True HEPA Whole Room Air Purifier with Allergen Remover Honeywell TRUE HEPA Germ Fighting Allergen Reducer Air Purifier 50250-S BLACK Commercial Industrial Ozone Generator Pro Air Purifier Mold Mildew Odor Ion 50W Xiaomi Mi Air Purifier 2nd Generation App Control Smoke Dust Filter Sanitizer Winix WAC5500 True HEPA Air Cleaner Purifier with PlasmaWave Technology Home Air-Zone XT-6000S Commercial Ozone Generator Room Deodorizer Honeywell True HEPA Air Purifier and Allergen Remover for Large Rooms New Air Purifier automotive PHILIPS GoPure Compact GPC10 HEPA HESA From Japan New USB Humidifier Fresh Air Purifier Moistener Steam Aroma Diffuser Night Light 110/220V 7/10g/hr Supply Ceramic Plate Ozone Generator Air Cleaner Purifier Kit SurroundAir SURROUND AIR Hepa & UV CLEANER Purifier MULTI-TECH XJ3000C New Comfort Whole House Air Purifier Black

New OION B-1000 Air Purifier Carbon Ionic Ionizer Negative Fresh Ions Pro Breezedvd lens cleaner currysLast updated: April 27, 2016.air duct cleaning lincoln city oregon We tend to think of air pollution as something that happensmountain breeze air purifier outside—but that's not always the case. Even inside your home, there are things like dust mites and dirt trodden in from outdoors to worryIndoor air pollution from sources like this can irritate your lungs and contribute to allergies and asthma. trouble is, if you use an ordinary vacuum cleaner, you might simply be "rearranging the dirt": your cleaner will trap some of the dust inside the bag or cyclone filter but let the rest

pass straight back into the room. If you suffer from asthma or another breathing difficulty, you may find a HEPA (high-efficiency particulate air) air purifier (or a vacuum with a HEPA filter) well worth the investment. Let's take a look at how they work. Photo: A typical HEPA filter from a householdYou can see the white, paper-like, fiber material folded and wrapped around like a concertina under the orange plastic top and bottom case. The folding greatly increases the area of the filter in contact with the airstream—effectively improving the filtration without reducing the The simplest kind of filter is a sieve: something with holes that are big enough to trap some particles and small enough to let othersSome vacuum cleaners do use filters like this to stop bigger particles of dust and dirt—but how do you catch smaller dirtYou could make a very fine filter or you could put several filters on top of one another, but in a vacuum cleaner they

would clog up very quickly and stop the machine from working. that, you'd need a more powerful electric motor to pull the air through the machine, and it would use more energy and cost more to run. Photo: The same HEPA filter with its gray outer gauzeThe air moves from the outside to the inside. You can see that the gauze works here like a sieve to stop larger bits of dirt getting anywhere near the filter inside. However, the inner HEPA filter works in a completely different way. The outer gauze "pre-filter" can greatly extend the life of the inner HEPA filter. HEPA filters in vacuum cleaners tend to use two quite different mechanisms to clean the airstream. First, there are one or more outer filters that work like sieves to stop the larger particles of dirt,Inside those filters, there is a concertina of what looks like folded paper designed to trap the smaller particles. paper is actually a mat of very dense glass fibers and, unlike the gauze,

it doesn't simply filter out small dust particles like a sieve. Instead, it uses three different mechanisms to catch dust particles as they pass through in the moving airstream. At high air speeds, some particles are caught and trapped as they smash directly into the fibers, while others snag on the fibers as they try to brush by. lower air speeds, dust particles tend to wander about more randomly through the filter (a process known as Brownian motion after its discoverer, Scottish botanist Robert Brown) and may stick to its fibers as they do so. Together, these three mechanisms allow HEPA filters to catch particles that are both larger and smaller The fibers in HEPA filters (shown here as gray bars) trap dust and dirt particles in three ways. into filter fibers and are absorbed by impact. Some are caught as they flow along in the moving airstream, move too close to a fiber and are trapped by interception. At lower air speeds, some are trapped by

diffusion (when randomly moving dust and air particles crash into one another and some are pushed into the filter fibers). HEPA was originally developed by the nuclear industry to help clean up dangerous, radioactive particles. Fortunately, most of us don't have to deal with such things—but HEPA filtration is still very useful and important in factories and workplaces, especially in environments where dust is produced as part of the manufacturing According to NIOSH (the US National Institute for Occupational Safety and Health), a true HEPA filter is one that can trap 99.97 percent of dust particles that are 0.3 microns in diameter (where a micron is one millionth of a meter). There's nothing particularly significant about particles 0.3 microns in diameter: they are simply the ones most likely to get through the filter, and smaller and larger particles than this are trapped even moreTo put 0.3 microns in perspective, it's worth

remembering that a typical human hair is roughly 50–150 microns in diameter, so a HEPA filter is trapping dust several hundred timesA genuine HEPA filter is much more hygienic than an ordinary one because it will stop mold spores and even some bacteria and When it comes to filters used in respiratory equipment, NIOSH recognizes nine different grades, based on three different levels of efficiency (95, 99, and 99.97 percent) and three levels of resistance to filter degradation (N, R, and P). N means not resistant to oil, R is oil resistant, and P is oil proof. So you might see a filter labeled N95 (95 percent efficient and not resistant to oil) or P100 (99.97 percent efficient and You might also see HEPA filters classified using the five letters A through E, based on how well they capture particles and resist airflow. Type A are the least effective that still meet the basic criteria for HEPA, while type E (at the opposite end of the scale) are military grade

filters capable of coping with chemical, radiological, or biological particles. a classification based on whether filters are fire resistant (type 1) or semi-combustible (type 2). Even if you're an allergy sufferer, these sorts of classification probably aren't going to be relevant if all you're doing is buying a simple air purifier or vacuum cleaner. For most people, the key thing is to make sure what you're buying has genuine HEPA filtration (remember, that's 99.97 percent of particles at 0.3 microns—often described as "true HEPA" or "absolute HEPA") by checking the particulate size quoted by the manufacturer. manufacturers who make vague, meaningless descriptions like "HEPA-like" and "HEPA-type" that aren't quantified in any way. A true HEPA filter will always quote theSome professional-grade vacuums will have extra mechanisms for dealing with particles even smaller than 0.3 microns, such as activated carbon granules (similar to those in water filters).

Finally, if you need industrial-strength air cleaning, there's a tougher standard called ULPA (Ultra-Low Penetration Air) that can catch 99.99 percent of particles 0.12 microns and above. Knowing a bit about how filters work comes in handy when you're deciding what to buy. A vacuum with proper HEPA filtration will channel virtually all (over 90 percent) of the dirty airstream through the filter; if it doesn't do this, it's simply rearranging the dirt. HEPA filters obstruct the airstream in vacuum cleaners: it takes quite a lot of suction to pull air past all those convoluted fibers. That's why vacuums with true HEPA filtration need more powerful motors and ones with low power may not clean effectively. Air purifiers that use HEPA filtration may have higher power consumption for the same reason (which means they're more expensive to run for long periods and noisier than rival technologies, such as photocatalysis, that work in different ways). A HEPA filter will also need cleaning or replacing periodically as well (which will add to the running costs);

might want to check how much replacement filters cost before you commit yourself. Photo right: The two HEPA filters in a Dyson vacuum cleaner (one above and one below the dirt cylinder) help to stop dust returning to the room. Like many other inventions, HEPA filters developed over time: there doesn't appear to be a single inventor who deserves sole credit. Fiber-based air filters were originally developed during the Manhattan Project (which produced the world's first atomic bomb) as a way of trapping extremely dangerous, tiny radioactive particles. After the war, German brothers Klaus and Manfred Hammes began developing relatively inexpensive air filtering systems during the early 1960s to reduce soot particles produced by coal-fired stoves; they went on to found a company called IQAir, which has been a pioneer of air filtering equipment ever since. The first inexpensive, pleated air filter was patented on April 19, 1966 by Kenneth W. De Baun and you can read all about it in his US Patent 3,246,457: Pleated Air Filter Cartridge.