Here we will review the top ten purifiers based on recommendations from Consumer Reports and other websites that perform a comprehensive tests and present them to consumers. So according to our analysis the top ten air purifiers are:

1. IQAir Health Pro. This air purifier which tops our top ten air purifiers list received the highest rating at Air-Purifiers-America.com and in other reviews. It can filter down to 0.1 micron level size particulates and performs very well on high speed but is a bit noisy. IQAir Health Pro uses hyper HEPA technology and can clean up to a 1,000 square foot room. The Hong Kong Hospital Authority used this purifier during the SARS outbreak. A more expensive unit is the IQAir Health Pro Plus which additionally removes odors.
2. Blueair 601. According to the 2007 Association of Home Appliance Manufacturers (AHAM) Directory of Certified Room Air Cleaners, the Blueair 601 is included in our top ten air purifiers has the fourth-highest clean air delivery rate (CADR) among 40 brands for dust, pollen and smoke removal. It can clean up to a 679 square foot room and has a 10-year warranty. It uses a combination of ionization and HEPA-like filters. Some reviews say that in using this combination technology, Blueair captures a higher percentage of allergens without releasing ozone into the air, like other electrostatic models.
3. Alen A375UV. This is considered the most advanced model under the Alen brand with HEPA filtration, 2 UV lamps for bacterial control, permanent titanium dioxide filter for volatile organic compounds (VOCs) and activated carbon for light odor removal. It is good for use up to 400 square feet.
4. Alen A350. This item was found to be quieter than IQAir Health and can clean from 400 square feet up to 800 square feet. Alen A350 contains one filter catridge that contains the HEPA filter, carbon filter and pre-filter all in one. So the replacement filter costs are less and it costs half as much as Blueair or AlenA375UV.
5. Eco-Rx Master Series RX400. Most reviewers prefer HEPA air purifiers over UV models but Eco-Rx can be comparable to IQAir Health Pro and Blueair models using a different technology. The sealed chamber of the Eco-Rx ensures that incoming air remains in the unit long enough to be decontaminated. It also has a safety shutoff feature to minimize the risk of accidental UV exposure. It covers up to 500 square feet. Like other UV-only purifiers, this model is effective only against biological contaminants.
6. AllerAir. This brand uses five stages of filtration and includes high grade activated carbon for chemical and gas control. AllerAir uses HEPA technology and can remove allergens, odors and cigarette smoke.
7. Austin Air Healthmate. Removes dust, pollen and odors in large rooms. Its pre-filters are washable and can be vacuumed. It employs true HEPA filter and controls mold spores, pollen, pet dander, light tobacco smoke and dust mites.
8. Whirlpool Whispure AP45030S. This model has a pre-filter for odors, a filter change indicator and push button controls. It can clean up to a 500 square foot area. The filter replacement cost can add up the cost though. Its pre-filter has to be replaced every three months and the HEPA filter should be replaced every year.
9. Honeywell Enviracaire 50250. This is one of the least expensive air purifiers to receive good reviews. Honeywell Enviracaire is a circular air purifier that has a pre-filter for odors and a HEPA filter to trap allergens. It is designed for rooms up to 375 square feet. This is a cheaper item than other purifiers but is also noisier.
10. Hamilton Beach TrueAir 04161. This air purifier has a HEPA filter, a carbon pre-filter and UV germicidal light. It can cover up to 200 square feet. The carbon pre-filter absorbs odor and the UV light kills bacteria. It works together with the HEPA filtration to be more effective and has a filter indicator.

What are air purifiers? What are the types of air purifiers? What factors should you consider when buying one?
Let us share with you the information we have gathered from the Environmental Protection Agency (EPA), The American Lung Association (ALA) and other consumer review sites that will provide you a comprehensive report about in home air purifiers and help you to choose the right one.
An air purifier is a machine that works to clean the air you breathe by getting rid of particles and harmful contaminants from the air in your home. Consumer report for in home air purifiers will tell you right off that you should not consider an air purifier as a silver bullet.
The use of air purifiers should be the last resort of the three-pronged approach towards improving the air you breathe inside your home.

The first one suggests to control the source(s) of pollutants or to reduce their emissions.
The second strategy according to the consumer report for in home air purifiers is to use a ventilation: open windows and doors (as the weather permits), turn on local bathroom or kitchen exhaust fans or use mechanical ventilation systems, which will help improve the air condition of your room.
The third one is to consider getting an air purifier that would actually eliminate bacteria, mold, viruses and any kind of odor.
The four general types of air cleaners available on the market are mechanical filters, electronic air cleaners, ion generators and hybrid devices. They can be incorporated into the central heating or ventilation system, tabletop units or larger portable room consoles.
Factors that you need to consider when buying an air purifier are:
Type of filter. Air filter protects the equipment, the furnishings, reduce housekeeping and building maintenance and reduce fire hazards. Lower efficiency filters can do all this. But it is only in portable room air cleaners that you can obtain sufficiently high levels of filtration that will protect your general well-being.
That’s where HEPA (high efficiency high particulate air) or formerly high efficiency particulate arrestors, are important. “True” HEPA allow no more than 3 particles out of 10,000 to penetrate the filtration media.
They are a bit noisy however. But since it can remove particles as small as 0.3 microns in size that are lung-penetrating particles, EPA and ALA and other organizations recommend using a HEPA filter if you want to use a mechanical filter.
Clean Air Delivery Rate (CADR). This is a standard developed by the independent Association of Home Appliance Manufacturers (AHAM) to measure the removal of dust, smoke and pollen from the air.
It measures the amount of clean air in cubic feet that an air cleaner delivers to a room per minute of a specific material. Note that a CADR of 50 is appropriate for a room of 80 square feet; a CADR of 80 for 120 square feet; a CADR of 100 for 144 square feet and a CADR of 200 for 320 square feet.
Cost. The costs you will incur in buying an air purifier may include the initial purchase of the unit, maintenance costs (cleaning and/or replacement of filters and other parts) and operating costs (cost of electricity).
The most effective units are generally also the most costly. However, you should check the initial cost with the maintenance cost as some air purifiers that are cheaper may turn out more expensive in the long run if you need to change filters often.
Noise. Air cleaners that have a fan can produce equivalent to a small vacuum cleaner when operating at a high speed. Even at low speed, some models still produce an annoying hum or whine.
You should also note that CADR rates are based on high speed. So it’s better if you purify a room an hour before you use it then turn down the speed when you’re there to minimize the noise.