Air Purifier Reviews

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Air Purifier Review

Why Buy an Air Purifier?

Indoor pollutants are a major concern. Studies conducted by the Environmental Protection Agency (EPA) suggest that some indoor air quality is two to five times more polluted than outdoor air. Air purifiers can assist in the battle against indoor pollutants by filtering the air in a room through several filters and capturing particles of dust, pollen and other allergens.

Air purifiers in a bedroom or living room will remove polluted air in the areas where you and your family spend most of your time. These devices come in a wide variety of designs and offer many different cleaning methods. We've rated the top air purifiers to help you find the right device for you. After comparing different room air purifiers, we found the Alen BreatheSmart, Coway and RabbitAir MinusA2 models offer the best purification systems. To learn more about battling indoor air pollution, see our articles about air purification.

Air Purifiers: What to Look For

The best air purifiers for home use effectively remove airborne particles in your home and operate quietly. In our research, we looked specifically at a model's performance in areas like pollutant removal, coverage area, noise levels, safety, energy use, additional features and customer support. We pulled these elements into several categories, and rated each air purifier based on functionality, safety, features and support.


Aesthetics and features are nice, but the most important thing to consider is an air purifier's basic ability to clean the air. Take note of the purifier's Clean Air Delivery Rate (CADR). This number defines how efficiently the air purifier eliminates tobacco smoke, dust and pollen from the air. The higher the CADR rating, the better, but look for an air purifier with a rating of at least 125 cubic feet per minute (CFM) in all categories. In general, you can use purifiers with lower CADR numbers in smaller rooms, while larger rooms require higher CADR numbers for maximum effectiveness.

To make sure your purifier will actually work on the room in which you plan to use it, check that it has the right coverage area. Manufacturers generally talk in terms of how many air changes take place in a given time, but there's little standardization between companies for these measurements. To compare the area coverage of the machines we reviewed, we determined the size of room in which the airflow allowed the air to be changed four times in one hour. If an air purifier can only perform one air change per hour in a large room, it is not fit for large rooms. However, if it can perform four air changes per hour in a small room, the purifier is ideal for small rooms. Typically, a small-room unit has an area coverage of under 350 square feet, and a large-room unit covers over 500 square feet.

Finally, in choosing an air purifier, you need to balance the appeal of a quiet machine with the functionality of a noisier one. A quiet system may not always move a lot of air, so you'll want the quietest air purifier with the highest air-movement volume. To evaluate this aspect, we looked at the noise level in decibels at the highest and lowest settings. The higher the decibel number, the louder the unit. You can check out the noise levels alongside the air-volume ratings to find a good balance.

Safety & Certifications

Several independent certifications can attest to the safety of your purifier. We recommend that you buy a product that's certified by Edison Testing Laboratories (ETL) or Underwriters Laboratories (UL). Most of the purifiers we reviewed meet one or both of these certifications. The ETL and UL marks assure that your purifier meets North American safety standards. To ensure you purchase an efficient machine, check that your air purifier is Energy Star certified.

In many purifiers, the process of removing odors creates damaging particles up to 10 times the acceptable standard for an indoor appliance, which can harm your respiratory health. These charged particles are created by ionizers, and while this is an effective method for removing smaller particles from your indoor air, the Asthma and Allergy Foundation of America (AAFA) and the EPA strongly discourage the use of ionizers. The EPA labels ionizers as ozone generators, and warns that prolonged exposure to these types of purifiers can actually worsen respiratory diseases and cause chest pain, coughing, shortness of breath and throat irritation. However, the best purifiers that use an ionizer have settings that allow you to turn the ionizer off or program the ionizer operate only at certain times, such as when you are out of the house, so that you're not exposed to the charged particles.


Convenience is an important consideration in an air purifier. Many machines have removable filters and a filter monitor, so you know when they need to be changed. Also check for purifiers that have a timer or sleep mode. With this feature, you can set the air filter to run for a set number of hours, making it easy to program the filter run or shut off when you are unable to adjust the settings, like when you're sleeping or away from home. Many purifiers also come with a remote control, which is a handy feature, but not really a necessity.

Some models also use an air-quality sensor, which will adjust the fan speed based on the number of particles the sensor detects. This is a handy feature because you won't have to adjust the fan speed manually. It allows you to program the machine once and then forget about it entirely.

Help & Support

Operating an air purifier shouldn't be too difficult, but it is still ideal to have support from the manufacturer in case something goes wrong. The best manufacturers offer at least a one-year warranty and online technical support, including FAQs, downloadable user manuals, online chat and direct contact information.

An air purifier can keep your home clean and free from dust, odors and allergens, which is one of the best ways to keep indoor air pollutants at a minimum. Air purification systems can help ensure your family isn't affected by airborne irritants.