When it comes to air filters, there are a variety of options available, each with its own set of advantages and disadvantages. The Department of Health recommends HEPA (High Efficiency Particulate Air) filters, which are capable of eliminating at least 99.97% of allergens and pollutants from the air, including mold spores and dust as small as 0.3 microns. HEPA filters are often used in air purifiers and vacuum cleaners, but they tend to restrict airflow so much that they are impractical for most residential forced air systems. We have tested more than 50 air purifiers over the past nine years and our measurements have shown that the exceptional Coway Airmega AP-1512HH Mighty is the best of them all.
It's powerful enough to use in a large room, quiet enough to sleep near it, designed to last for years, and economical enough to be installed in multiple rooms. The Coway Airmega 200M is practically identical to Coway's Airmega AP-1512HH Mighty in every important way. They are equivalent in noise and performance measurements, their filters are interchangeable and their similar controls allow the lights on the screen to be turned off. The 200M has a square rather than a round grille, but that's the only important physical difference. If you prefer the look of the 200M or find it at a better price, we recommend it.
The Levoit Vital 200S equaled the Coway Airmega AP-1512HH Mighty in performance tests, and both are very similar in terms of energy efficiency, noise emission and ability to turn off the screen while maintaining the fan configuration you choose. However, the Vital 200S is a new version (January 2020), so we haven't had time to test it in the long term yet. In conditions where air quality is poor, such as when an area is affected by a nearby wildfire, we recommend running air purifiers at a high temperature for one hour and then setting them to low or medium temperature to create and maintain clean air in the home. After burning 15 wooden matches (to create an initial heavy load of fine smoke particles), we tested this method with the Coway Airmega AP-1512HH Mighty and the Airmega 400 for three hours, one hour at high temperature, followed by two at medium temperature. Each of the fiberglass, polyester, washable, pleated and electrostatic filters offers different air filtering capabilities. The MERV standard is mainly used to measure the performance of filters designed for forced air conditioning systems.
When choosing air filters to install in your oven, air conditioner, or heat pump, pay special attention to their efficiency ratings. Remove the plastic bag the filters come in, put them back in the machine and you're good to go. While The Home Depot uses the FPR, the industry standard is to use the Minimum Efficiency Reported Value (MERV) air filter classification system. When in doubt, check the appropriate dimensions of the filter in your equipment's owner's manual or contact the manufacturer. Before making any changes to an HVAC system's air filter, users should consult their HVAC manual or consult an HVAC professional.
On the other hand, in HEPA purifiers, a fan extracts particles suspended in the air through a dense felt-like filter that has billions of small holes of different sizes. If the current filters are perfect, note (or take a picture) of the size printed on the filter frame. This means that it is optimized for larger particles suspended in the air such as pollen and mold spores and not for very fine particles such as smoke from wildfires (such as HEPA filters). In addition, it uses the same technology and combines a filter that is not HEPA (but is very efficient) with a system that imparts an electrical charge to any particle that passes through it helping it to adhere to the filter the next time (basically through static adhesion).
If you suffer from allergies or are simply concerned about the air quality in your home a HEPA air purifier can help. At MERV 13 -the highest rating you'll find for most popular residential HVAC filters- you can count on the filter to stop bacteria smoke and other microscopic particles.
