HEPA Purifiers

Though HEPA filters may seem to be a new technology, the concept was actually developed during the Second World War by the US Atomic Energy Commission. It was first made to capture and remove radioactive dust from the air that could have presented a hazard to workers. The HEPA filter was designed to protect the human respiratory system. In fact, the US Centers for Disease Control (CDC) guidelines for preventing transmission of tuberculosis recommend that HEPA filters be used. They are designed to filter out 99.97% or more of particles that are 0.3 microns in diameter or larger.

A micron is a metric unit of measure that’s equal to one millionth of a meter. It is 1000 times smaller than a millimeter. The unaided human eye cannot see particles that are under 10 microns in diameter. Particles of 0.3 microns are the most difficult particles to trap within a filter because of their size. When inhaled, a 0.3 micron particle easily enters the body’s respiratory system, so that the body’s immune system is vulnerable to attack from them. That is the main reason why doctors highly recommend HEPA filters for controlling particles that aggravate asthma and allergies.

HEPA-based air purifiers are fine to leave on constantly. In fact, it is recommended for continuous cleaning of the air. Additionally, if a HEPA purifier is turned off for a long period then switched back on, some of the particles could find their way back into the air. Leaving a HEPA air purifier running continuously is best. When you do shut the HEPA air purifier off for a period (for example, while you will be on vacation and your home will be unattended) it is a good idea to go ahead and change the filters before turning it back on.

Keep in mind when choosing an air purifier that a higher wattage unit does not necessarily mean there is a stronger fan motor. Check the Clean Air Deliver Rate (CADR) number to learn how much air the fan moves. Higher wattage simply corresponds to the amount of electricity used to run the unit. Also, energy efficient air purifiers generally cost more, but they may also be quieter, which is an added bonus. Portable HEPA air purifiers with high quality energy efficient fan motors should from 80 to 200 watts on machines with CADR ratings of 350 to 600.

Not all of the particles that a HEPA purifier cleans from the air are as small as the 0.3 micron diameter minimum that HEPA filters filter out. Many other contaminants are much larger. For example, a human hair is 70 to 100 microns in diameter, and the droplets in a human sneeze are generally 10 to 100 microns in diameter. Pet dander can be anywhere from 0.5 to 100 microns in diameter, while pollen ranges from 5 to 100 microns in size. Plant spores are generally in the 6 to 100 micron range, while mold ranges from 2 to 20 microns in diameter. Smoke particles can be very tiny: 0.01 microns to 1 micron, while dust mite debris is larger: 0.5 to 50 microns. Most household dust ranges from 0.05 microns to 100 microns, skin flakes range from 0.4 to 10 microns, and bacteria are anywhere from 0.35 to 10 microns in diameter.

Air Purifiers For The Home

Three of the best air purifiers for the home are the Honeywell 50250N, the Hamilton Beach 04383, and the Rabbit Air BioGS 421A. Here are some of the features that make these three top choices in home air purification.

1. The Honeywell 50250N

The Honeywell 50250N

The Honeywell air purifier model 50250N is a true HEPA air purifier. This means that it uses a High Efficiency Particulate Air (HEPA) filter, which filters out 99.97% of particles that are larger than 0.3 microns in diameter. It has a Clean Air Delivery Rate (CADR) of 250, and that makes it appropriate for a room of 375 square feet in area. The Honeywell 50250N retails for around $160 and according to several consumer publications is the only air purifier costing under $200 that can clean air effectively. With most HEPA air purifiers, filter replacement can be a significant added expense, costing up $100 or more per year. However, the Honeywell 50250N has a permanent lifetime HEPA filter, so replacement costs are not an issue. It also has an activated carbon pre-filter. This protects the HEPA filter, trapping larger particles and absorbing volatile molecules that cause odors.


2. Hamilton Beach 04383

Hamilton Beach 04383


The Hamilton Beach True Air 04383 is a great value. It is very simply designed, with a powerful, 3-speed fan that moves the air in a room through a filter that does not have to be replaced. The filter is cleaned with regular vacuuming. The fan in the Hamilton Beach 04383 is powerful for the size of the machine. On the highest speed, it is, of course, louder, but the lowest fan speed is quiet enough to be unobtrusive. When set up horizontally, air flows through the front of the machine and exits at the top. It can be set upright as well, and in this position, it moves air laterally very efficiently, adding extra comfort on warm days by making the room feel cooler.


3. Rabbit Air BioGS 421A

Rabbit Air BioGS 421A

The Rabbit Air BioGS 421A has a charcoal pre-filter that can be washed in the sink, or even put through the dishwasher, and the HEPA filter has an antibacterial / antiviral coating, cleaning air even more efficiently. The filters should last for 18 months under continuous use. This air purifier comes with a five-year warranty, which is uncommon with small air purifiers. The front display has a clean, high-tech look to it, and the body of the air purifier has an anti-static coating that prevents build-up of dust. The HEPA filter has a gasket on its bottom edge, which prevents air leakage and makes sure that air passing through the filter is cleaner. Odor and particle sensors on the front of the machine work well and are not just a gimmicky add-on. You can spray air freshener in the same room and the lights will come on shortly afterward.


Air purifiers are made to cut down on airborne contaminants inside homes. When well maintained, they can be very helpful for those with asthma or allergies. Here are a few tips for choosing an air purifier.

First, identify the source of your indoor air contaminants. Common ones include pet dander and hair, cigarette smoke, and pollen. Once you identify the main source of indoor air pollution it is easier to choose an air purifier to address that particular contaminant. Generally speaking, HEPA air purifiers do a good job for overall air purification. They work great against pet dander, dust, and pollen. For getting rid of odors such as cooking odors, and smoke, an activated carbon filter is best. There are some air purifiers, such as the Honeywell 50250N mentioned above, that have both a HEPA filter and a carbon filter. For houses with mold, mildew, or other biological contaminants, an air purifier with an ultraviolet lamp works best for killing such biological pathogens.

An air purifier’s clean air delivery rate (CADR) refers to a measurement made by the Association of Home Appliance Manufacturers, AHAM, to help people choose air purifiers for different sized rooms. Since CADR is based on the number of cubic feet of air that an air purifier cleans per minute, the higher the CADR number, the more efficient the air purifier is at cleaning the air, and the larger the room the purifier will effectively clean.

UV Air Purifier Information

Several home air purifier manufacturers have started including an ultraviolet (UV) lamp in their air purifiers. The reason for a UV lamp is that ultraviolet light in sufficient doses kills certain harmful microorganisms like viruses and bacteria. The people who are most at risk from airborne harmful microorganisms are very old people and very young people. That’s why air purifiers with UV stages are often seen in nursing homes and in child care centers and pediatrician offices.


Ultraviolet light is invisible to the human eye. The wavelength of UV light is shorter than the shortest-wavelength light we can see, which is violet. There are three types of UV light: UVA, the longest wavelength UV light; UVB, which is shorter in wavelength than UVA, and the shortest of all, UVC, which is the range of UV light that kills bacteria and viruses. Any type of UV light can damage the eyes and has been linked with the development of skin cancer, so it is very important to protect your eyes when checking on the UV lamp in an air purifier. Chances are that the light in the air purifier will not be direct enough or strong enough to damage eyes, but it is best to be safe.

The way UV light kills harmful microorganisms is that at it scrambles the organism’s DNA. The two wavelengths of UV light that are the most potent for killing bacteria and viruses are 185 nanometers and 265 nanometers. A UV lamp in an air purifier that claims to kill microorganisms should emit energy in one or both of these wavelengths.

The problem with UV lamps in home air purifiers is that the bulbs will still appear to work, because they light up in a violet color, even though they have stopped emitting light in the proper range to kill microorganisms. One way to avoid this problem is that when you put in a new UV bulb, you can write the date on the bottom of the air purifier, or put it on your calendar. The instruction manual that came with your air purifier will tell you how often to replace the bulbs, and you should write down this date or mark it on your calendar as well.

Even though UV rays are great for killing bacteria and viruses, they are not functional unless there is a filter of some sort (like a high efficiency particulate air, or HEPA filter) that filters air before it reaches the lamps. Without a particulate filtering system, there may be enough particulates to shade the microorganisms from the UV light. In most home air purifiers, the UV stage of the process comes last so that the air flowing through the UV light is as particulate free as possible.

Why is Carbon Used in Air Purifiers?

Activated carbon is used in home air purifiers because, like air sponges, carbon filters trap airborne odors and gases. The reason it is called "activated" charcoal is that it’s been treated with oxygen. This opens up tiny pores between the carbon atoms and the pores trap the odors and gases. Carbon granules have a very convoluted surface, providing it with a large surface area to volume ratio, which makes carbon filters tops for trapping the gases that go through particulate filters first. But eventually, the pores become clogged with contaminants, and the filters must be replaced to function properly.


(Picture Caption) You an see in these closeups that activated carbon has a honeycomb formation. The odors and gases become trapped in the honeycomb pores.

Is One Activated Carbon Filter as Good as the Next?

No. Sometimes activated carbon is impregnated with special materials that make them more effective at trapping odors and gases. These specially enhanced activated carbon filters are able to remove the so-called volatile organic compounds, or VOCs from the air.

How Much Activated Carbon is Necessary?

In general, more carbon is better because as soon as all the pores in the surface of an activated carbon filter are plugged, the filter is no longer effective. Greater amounts of carbon will make a filter work better and last longer than a filter that only has a small amount of carbon. Filters with only small amounts of carbon can become useless in a matter of weeks. The best activated carbon filters have larger amounts of activated carbon. Some of them can last for over 18 months.

How Thick Should the Carbon Filter Be?

The thicker the better. The more time that the pollutant has contact with activated carbon, the better its chances of being trapped. Therefore, the thicker the layer of activated carbon the air flows through, the better the results.

What is the Difference Between Pads Impregnated with Carbon and Granular Activated Carbon?

Granular activated carbon is better. In fact, granulated activated carbon is better than a carbon pad filter of two inches thick or more. That’s because it has a greater surface area to volume ratio for trapping gases and odors than the impregnated pad filter. Pad filters with activated carbon will have to be changed far more frequently than activated carbon granule filters. The more contact the air has with the carbon, the greater the chances of the pollutants being trapped.

In summary, activated carbon is considered a "miracle filter" by many researchers. It has a great capacity for getting rid of unpleasant odors and volatile organic compounds, including those from pesticides. Activated carbon acts as an air sponge, trapping pollutants in its tiny pores. Activated carbon is the most preferred substance for removing numerous possibly hazardous or carcinogenic chemicals in the air. It’s likely that you will need to replace carbon filters every year or more depending on your air quality.

Guide to Air Purifier Repair

Indoor air pollution is a fact of life, and in many cases the air indoors is less healthy than the air outdoors. Between dirt, pet dander, dust, and various microorganisms, indoor air can get quite dirty. Many people use air purifiers to make the air that they breathe inside their homes cleaner. But like every other electronic appliance, air purifiers get dirty, and when that happens they run far less efficiently, but there is a lot you can do to improve its efficiency if you’re a reasonably confident do-it-yourselfer.

air-purifier-repair Home air purifiers are fairly simple devices, and periodic maintenance according to the instruction manual can keep them running efficiently.

You’ve probably at some point noticed a layer of dust built up on top of your television or on a table in your home and wondered just how much of the stuff their is floating around in the air. Believe it or not, in an average home, every cubic foot of air has some 3,000,000 particles of dust suspended in it!

Air purifiers come in two basic types: mechanical and electronic. With a mechanical air purifier, a fan draws air through one or more filters. Typically, a pre-filter removes the biggest matter (such as pet hair), and then a filter with activated charcoal is next in line to remove odors. Third is usually a high efficiency particulate air (HEPA) filter, which removes more than 99.97% of particles that are 0.3 microns in diameter or larger.

Electronic air purifiers use a simple device called an electrostatic precipitator to remove particles like pollen and smoke from the air. Electrostatic precipitators charge air particles positively and then traps them on a grid that is negatively charged. This type of air purifier often contains a pre-filter and perhaps an activated carbon filter to get rid of dust and odors as well. Some of them also contain an ionizer, which is not the same thing as an electrostatic precipitator. An ionizer releases negatively charged ions (and sometimes ozone) into the surrounding air to trap dust particles.

Possible Air Purifier Problems

Depending on how many different filters and features an indoor air purifier has, a number of things can go wrong. Many of them are simple problems that you can fix yourself. Problems such as a dirty precipitating cell, dry motor bearings, clogged filters and air intake, bent collector plates, or broken ionizer wires can often be fixed right at home.

How to Fix Common Air Purifier Problems

1. Cleaning Grill and Filters


For a mechanical air purifier, the first step is to turn the machine off and unplug it from the wall.

Usually there will be release buttons that allow you to remove the intake grill containing the foam pre-filters. Do this and remove the filters. To clean the foam filters, remove them and vacuum them through the grill (so the vacuum won’t attach itself to the filter while you’re using it).

Next remove the screws that hold the filter housing. Vacuum or clean with a soft cloth. If you use a vacuum, keep the screws and other small parts that could be sucked up by the vacuum away from the part you’re vacuuming.

2. Cleaning the Fan


If you need to get to the fan, take out the long screws that hold the housing together and gently pull the two halves of the housing apart.

The fan will have a locking ring on the end of the motor shaft. Put on a pair of safety goggles and remove the fan by twisting or prying the locking ring, but be very careful that you don’t bend the ring.

Take out the screws that hold the motor housing and the switch together. Pull the motor housing apart so you can see the motor. At this point, the switch module should slide out from the housing. You can clean the parts off with a soft cloth.

3. Replacing Broken Ionizer Wires

Ionizer Wires

You can replace broken ionizer wires with replacement wires. Your owner’s manual for the air purifier will tell you where you can get replacement wires. Making sure that the air purifier is turned off and unplugged, remove the precipitating cell according to the owner’s manual instructions. Generally, you use a pair of needle nose pliers to disengage the wire spring from the connector on each end. You may need to press down on the connector with a screwdriver to free the wire. then you reverse the procedure to put a new wire in place.

3. Testing the Precipitator Cell


If you want to test the precipitating cell, you need to be familiar with using a multimeter. If you’re not, you probably shouldn’t do this. First, remove the precipitator cell from the machine. Set the meter for Resistance x 1, which may be labeled Rx1 on your meter. Clip one probe to the frame of the precipitator cell, and then touch the other probe to the ionizer terminal, then touch it to one outer collector terminal, and then the other outer collector terminal. If your reading is "1" (which means "infinity"), the cell is working properly. If you get a lower reading, the cell has a short circuit and you need to replace it.


With the right tools and information you can pretty much repair any living air, shaper image (ionic breeze), oreck, ecoquest and even the full range of Honeywell purifiers. If you follow our guide and your purifier still does not work then you will likely have to take it to a electronic appliance specialist.

Advanced Pure Air Newport 9000

The Advanced Pure Air Newport 9000 is marketed by Real Spirit USA and is manufactured in China. It strongly resembles the Mitsubishi MHI-6800 Intelli-Pro, with a futuristic design and shape. The Advanced Pure Air Newport 9000 is sold at Costco, Sam’s Club, Amazon, and Target for just under $280. While it doesn’t contain any breakthrough technology, it does contain several air cleaning technologies in one package. It monitors air quality for both dust and odor and has an LED four-level display showing indoor pollution levels as well as a sensor that indicates when the filters need to be replaced or when the electrostatic collection grid must be cleaned. The fan speed adjusts to pollutant levels, and it runs fairly quietly on all speeds.

Advanced Pure Air Newport 9000

Measuring 13.5 x 10 x 25.6 inches, the Pure Air Newport 9000 has air flow of 106 cubic feet per minute, which is fairly low power. While the manufacturer says that the machine can be used in rooms up to 750 square feet, this is a stretch. It is more suited to rooms of under 200 square feet in size for effective levels of air turnover. This air purifier has a series of filters including a washable pre-filter, an electrostatic precipitator, an activated carbon filter, a high efficiency particulate air (HEPA) filter, a photocatalytic oxidizer, an ultraviolet light, and a negative ionizer.

The ultraviolet light is designed to kill dangerous microorganisms. It is a six watt lamp that emits at 254 nanometers, which is not very high powered. The electrostatic precipitator must be cleaned frequently and regularly to keep it working properly. This is true for many models that use electrostatic precipitators. But even when the electrostatic grid is dirty, the HEPA filter will continue to work, and if the grid is kept clean, the HEPA filter will last longer.

The frequent cleaning of the electrostatic grid is perhaps the main gripe of users, but this is true of many air purifiers in this price range. It does not produce any ozone, and odor removal is slightly above average. The gaskets and seals do their job well, and this helps eliminate problems such as dirty air bypassing the filters. Each filter can be replaced independently, which is convenient for those who don’t like having to buy a suite of filters at once. The filters are inexpensive as well. Overall, the Advanced Pure Air Newport 9000 is a decent machine for the price. It is attractive, convenient, and easily portable. Though the series of filters and cleaners may be a bit of overkill, all the technologies are useful and the only drawback is the need for keeping the electrostatic grid clean for optimum performance.

Coway Air Purifier

The Coway AP-1009CH Air Purifier is built in Korea by Woongjin Coway. The brand was introduced to the U.S. in 2007, and was rebranded by retailers like Lowes and Sears. Coway dominates the air purifier market in Korea, claiming 40% of sales there. The AP-1009CH is a mid-market product at $279 and is sold by Amazon, Walmart, and AirPurifiersAmerica.com. EPA Energy Star states that the Coway AP-1009CH has a clean air delivery rate (CADR) of 186.9 for dust, 149.9 for smoke, and 203.8 for pollen (for an average of 180). These rates make this air purifier suitable for small and medium rooms.

The AP-1009CH has a three stage filter system and four fan speeds, from silent to turbo. The first filter is a washable pre-filter, which is followed by an activated carbon filter for removing odors. The main filter is a 3M HEPA filter that is designed to capture 99.97% of particles greater than 0.3 microns in size. The user manual suggests that when vacuumed regularly the HEPA filter can last up to three years. The pollution indicator is a lamp that goes from blue to red depending on air quality levels. The indicator resembles a mood ring.

This air purifier has a rounded, futuristic shape and is pitched toward women, with floral designs on the product literature. Complaints about the AP-1009CH air purifier have been few, with some users reporting a temporary odor when the machine is switched on for the first time. It is extremely quiet, at only 22.4 decibels, which is suitable for sleeping. It measures 25.8 x 14.3 x 8 inches in size and weighs 13 lbs. It stops automatically when the front cover is open or removed. This air purifier earned the EPA Energy Star rating, using only 37.8 watts on its highest setting. It comes with a one year warranty.

The bottom line is that even though the initial price may seem high, the AP-1009CH has low maintenance costs and energy consumption. It is very attractively designed and suitable for those who want clean air, but it is not powerful enough for those who have serious health issues. The washable carbon filter is fairly light duty, but can tackle odors fairly competently. It is stylishly designed, very quiet and is considered a good value in terms of price and performance.

Panasonic Air Purifier F-P15HU2

The Panasonic F-P15HU2 air purifier retails for around $540. It is a small air purifier with a high efficiency particulate air (HEPA) filter (model F-Y15XS, $36) and a charcoal filter (model F-Y55XS, $28). This is an automatic, electronic air purifier that is a good choice for a single room. For its price range, the F-P15HU2 is quiet. When set on a low, but still useful, air volume exchange rate, it is quiet enough for undisturbed sleep. Rated as a "best buy" by consumerguide.com, the F-P15HU2 does not include a pre-filter that some air purifiers use as protection for the main HEPA filter. However, it does have a pre-filter layer attached onto the HEPA filter that can be cleaned easily. The HEPA filter removes 99.97% of airborne particles of 0.3 microns in size and larger, though on high speed, there is some loss of efficiency. The deodorizing filter has activated charcoal and lasts up to one year.


With three fan speeds, plus a "super" burst mode setting for quick particle removal, the F-P15HU2 claims a clean air delivery rate (CADR) of 150 and will clean rooms of up to 216 square feet. The decibel levels on each of the four speeds, starting with the highest are: 56 dB, 48 dB, 40 dB, and 30 dB. The sensor monitors particle levels and lights up LED lights on the monitor to indicate the approximate particulate level. The more red LED lights that are lit up, the dirtier the air. The fan will automatically work faster until the air is cleaned. When the air has been suitably cleaned, the LED lights turn green, and the fan speed slows. It can also be used in timer mode to turn on and off at specified times, and it has an interval mode for energy savings.

User-reported drawbacks of the F-P15HU2 include energy use, which is 101 watts on the highest speed, down to 43 watts on the lowest. Automatic controls, timer mode, and interval mode can effect some energy savings. Some users report that replacement filters can be hard to find, so it may be wise to find a supplier online or elsewhere before committing to the F-P15HU2. The carbon filter does not have carbon volatile organic compound (VOC) capability, so it is not tops at removing odors and gases from the air.

Overall, the F-P15HU2 is highly ranked by users, earning five stars out of five from seven Amazon customers. It is a compact (15 5/8 x 21 1/4 x 6 inches) and convenient design with a cord that’s just over eight feet long. It will fit on shelves and wide window sills and weighs about 14 lbs.

Ion Purifier: Pionair air filter?

The Pionair ion purifier does not have a filter and doesn’t trap airborne particles such as pet dander or hair. In this sense, it is more like an air sterilizer than an air purifier. The Pionair uses negative ionization and photocatalysis to clean the air surrounding the machine. Prices range from approximately $400 to $600, and the machines are made in the U.S. by HealthQuest Technologies in Georgia. A purifier like the Pionair works best in humid environments where conventional high-efficiency particulate air (HEPA) filters don’t work as well, such as damp rooms like basements and bathrooms. In these environments, mold spores and musty smells accumulate, and this is where the Pionair works best.


The Pionair uses a photocatalytic air purifier that uses titanium dioxide as a catalyst, and an ultraviolet light bulb to create hydroxyl oxidizers. This is a fairly new technology and can be used instead of ozone. The Pionair does not have a fan but draws air in due to a chimney-like effect created by the light bulb. Because there is no fan, the clean air delivery rate is very slow. However, the Pionair is very quiet and is not designed to do the same job as a traditional HEPA air filtration system. The ultraviolet bulb used in the Pionair will have to be replaced after about a year. While the bulbs are fairly expensive, the cost is comparable to the replacement filter costs for traditional air purifiers.

Drawbacks to the Pionair purifier include the steep price compared to the size room it can treat. Also, the Pionair does produce ozone due to a wider wavelength distribution in the ultraviolet bulb. Light with a 254-nanometer wavelength is germicidal, and light with a wavelength if 185 nm is ozone generating. However, the production of a bulb that is made specifically for 254 nm is more expensive, so Pionair elected to include the 185 nm light in its bulb. The biggest drawback is that it is not designed to rid the air of particles, and often it is particles that aggravate allergies. On the other hand, HEPA air cleaners don’t do so well in damp, moldy environments like basements.

Overall, the Pionair ion air purifier is suitable for cleaning the air in fairly small rooms where particle removal is not a high priority. It is small, easily portable, and uses very little electricity (25 watts). Because there is no fan, the unit is very quiet. Though there is no filter, the ultraviolet bulb does have to be replaced periodically. Over three to five years, users will spend a comparable amount on replacement UV bulbs as they would on replacement filters for a traditional air purifier.

Sun Pure Air Purifier

The Ultra Sun air purifier is a premium-priced air purifier that uses multiple filters as well as ultraviolet technology to clean and sanitize the air. It retails for around $600. A pre-filter removes particles larger than 5 microns in size and is easy to clean with a vacuum cleaner. Next, two layers of gas and odour absorption use activated carbon, zeolite, and potassium permanganate layers make up this filter. The HEPA filter is next. True HEPA filters remove 99.97% of particles that are 0.3 microns in size or larger. The next step in Sun Pure’s filter system is a photocatalytic oxidation chamber. It has a titanium dioxide grid that is activated by ultraviolet light. Photocatalytic oxidation is a new enough technology that its usefulness in-home air purifiers is not really quantified yet. sun-pure-air-purifier One of Sun Pure’s marketing angle is that its air purifiers use photocatalytic oxidation to get rid of toxic chemicals in the air as opposed to traditional HEPA filter-based air purifiers, which use carbon filters. Though Sun Pure claims that the machines can purify the air in very large rooms, that figure is only accurate for one air change per hour, which is insufficient for most people. It does, however, purify the air in a room of 300 to 350 square feet with six air changes per hour with the machine set on its highest setting. The Sun Pure has computerized controls that allow four speeds and seven-room sizes for a total of 28 power settings. Sensors alert the user to airborne contaminant levels with easy to understand green, yellow, and red LED displays so the user can turn the machine off if the air is already clean. The purifier also uses infrared motion detectors that turn the power down when there is less movement in the room. The Sun Pure air purifier is not the quietest, with 68 decibels (dB) recorded on its high setting and 58 dB on the low setting. Another gripe besides the noise is that the cardboard frame holding the HEPA filter doesn’t seal securely to the chassis, potentially drawing dirty air around the HEPA filter rather than through it. In summary, the Sun Pure air purifier is expensive but uses both HEPA filtration and photocatalytic oxidation, aimed at removing particles as well as chemicals and odours. It weighs 23 pounds and measures 21.5 x 18.9 x 8 inches, making it unsuitable for placement anywhere other than the floor. It is well made, and maintenance costs are low. Filters and UV bulbs are sold separately so that users can replace one without having to replace all consumables. Its automated controls are very appealing to some users. For those with the budget to accommodate a Sun Pure air purifier, it is certainly worth considering. Sadly, this product has been discontinued and is no longer available for sale. If you are interested in finding out the best air purifier available to buy in 2020 then be sure to check out our list of the best available at the moment:

1.Austin A250B1 – Best Overall
Austin Air A250B1 HealthMate Plus Junior Air Purifier, Black
  • Designed for people living in smaller spaces and specializes in the reduction of harmful chemicals, noxious gases, VOC’s, formaldehyde, and sub micron particles for individuals in the most contaminated of settings
  • Broad spectrum adsorption offers protection for people exposed to smoke from wildfires, those living close to busy highways, and people with sensitivity to certain chemicals and gases found in the home
  • True medical grade HEPA filter removes 99.97% of all particles larger than 0.3 microns; over 270 cubic inches of activated carbon impregnated with potassium iodide and zeolite filtration removes odors, gases and chemicals including formaldehyde and benzene
  • 3 speed settings for fan; 360 degree intake system draws air into all sides of unit, passing air through a 4 stage filter
  • Eases headaches and reduces nausea related to chemical exposure; helps reduce coughing, wheezing and sneezing, dry mouth, runny nose; reduces night time allergies and asthma attacks, snoring, and helps you sleep better; strengthens the immune system

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2. Medify MA-40 2.0 – Great if you can afford

Medify MA-40W2 V2.0 Medical Grade Filtration H13 True HEPA for 840 Sq. Ft. Air Purifier, 99.97% | Modern Design - White (2-Pack)
  • Medical Grade H13 Filters (higher rated than True HEPA) 99.97% particle removal. H13 True HEPA is considered medical grade air filtration, the unit alone is not a medical device.
  • Cleans a room up to 1,600 sq ft in one hour, 840 sq ft in 30 minutes, 420 sq ft in 15 minutes (CADR 330)
  • To make V2.0 quieter in 'Sleep Mode' and Speed 1 the ionizer is automatically turned off, on speed 2 and 3 it can be turned on/off as needed | CARB, Energy Star & ETL certified.
  • Tempered Glass panel (like your cell phone, easy to clean, won't scratch like cheap plastic models), Sleep mode and 3 fan speeds, 8 hr timer, night mode, child lock
  • Genuine Medify Replacement Filter: B07MTQFFNT, 110 Volt units, USA registered Lifetime Warranty

3. LEVOIT CORE 300 – Quite a machine for less than $100

LEVOIT Air Purifier for Home Allergies Pets Hair Smokers in Bedroom, H13 True HEPA Air Purifiers Filter, 24db Quiet Air Cleaner, Remove 99.97% Smoke Dust Mold Pollen for Large Room, Core 300, White
  • Genuine Replacement Filters: Search for core300-rf or core 300 replacement filter for Replacement Filters. Use genuine Levoit replacement filters to maintain the best performance and to ensure what you're buying is worthy of your investment
  • Higher Purify Performance: Use the Core 300 to fill your environment with crisp, clean air. Its Vortexair Technology creates a stronger air flow, CADR number is 230+m3/h, allowing it to cover up to 219 sq. ft. AC 120V/60HZ for USA and Canada
  • Improved Filtration: With larger expansion area and longer length than others, the H13 Ture HEPA filter works with ultra-fine Pre-filter and activated carbon filter, trapping 99. 97% of fine particles and allergens as small as 0. 3 microns and large pollutants such as dust, pet dander, smoke, mold, pollen
  • Most Silent Air Cleaner: The noise level is nearly voiceless at sleep mode with only 24db, its QuietKEAP Technology reduces noise so you can sleep in a restful and soothing indoor environment
  • Ultra-long Service Life: Industry leader provider's bearing makes this levoit core300 hepa air purifier durable and reliable. The AC capacitor motor uses durable high-precision bearing, and excellent internal structure increases abrasion resist, which obviously extends the life of machine

4. Coway Airmega 300 – Not cheap but great for large spaces

Coway AP-1512HH Mighty Air Purifier with True HEPA and Eco Mode
  • Coway Mighty (AP-1512HH) is designed to accommodate room sizes up to 361 sq.ft (CADR: Dust 246 / Pollen 240 / Smoke 233 cb. ft.).
  • 4 Stage Filtration System (Pre-filter, Deodorization filter, True HEPA filter, Vital Ion) captures and reduces up to 99.97% of particles 0.3 microns in the air, including pollen, pollutants and other allergens. It also reduces volatile organic compounds and reduces odor.
  • Coway Mighty pollution sensor communicates indoor air quality in real-time. The brightly colored LED lets you know how clean or dirty your indoor air is every minute of the day. And it features a timer, and filter lifetime indicator.
  • Fan speeds available in 1, 2, 3 stages by manually setting up. While auto mode automatically optimizes the speed setting 1 through 3 based on the level of indoor air quality. When no pollution is detected for 30 minutes, the fan will automatically stop and set as Eco mode to save energy.
  • Timer feature allows the machine to run 1/4/8 hours before automatically powering off.

5. Sharp FPF30UH – Great for small spaces and tight budgets

Sharp, White FPF30UH True HEPA Air Purifier for Home Office or Small Bedroom with Express Clean. Filters Last up-to 2 Years for Dust, Smoke, Pollen, Pet Dander, 143 Square Feet
  • SMALL ROOMS: Designed for Rooms up to 143 sq. ft.
  • CADR Dust (101) / Smoke (92) / Pollen (109)
  • Long-Life TRUE HEPA Filter Lasts Up-to 2 Years (actual filter life will differ depending on the environment)
  • True HEPA Filter Captures 99.97% of Allergens as Small as 0.3 Microns that pass through the filter
  • The Library Quiet, Sleep Setting is Perfect for the Bedroom or Home Office (as low as 23 dba)