How clean is the air you breathe?
Many homes are plagued by airborne contaminants, which often have
harmful side effects to your health. In fact, your indoor air is usually much more polluted than the outdoor air. View the “more information about IAQ” portion of this website for more information.

I have seen many different efficiency ratings, what do they mean?
Air cleaner efficiency is a rating that tells how many airborne pollutants are removed by the air cleaner’s function. Unfortunately, you will find many different ways to test efficiency in the air cleaning industry... so, it’s difficult to compare one manufacturers unit to another unless you know what to look for. There are three essential topics that must be evaluated:

Airborne Particulate Size - You must know the size of particulates that are being used to conduct the efficiency test. Micron is a size measurement, a very small size measurement. A pencil point, for example is 200 microns... a human hair is 100 microns thick. Most airborne contaminants are between .001 and 100 microns, some objects are so small that they can only be viewed by an electron microscope.

Examine extra carefully any efficiency test that only counts the particles 3 microns and larger. These tests don’t count smoke, viruses, and other pollution smaller than 3 microns in size.

Airflow restriction - You must know the amount of air restricted by the air-cleaning device. Free airflow is essential for heating and air conditioning equipment functionality, efficiency, and durability.

Some HVAC technicians use the “plywood analogy”. The plywood analogy simply gives us a visual representation of restricting air flow … if a piece of plywood was installed inside your duct work as an air cleaner you would have 100% catch efficiency on all particulate sizes, but you would also have 100% air flow restriction. Obviously, this is a ludicrous example but you should now see the balancing act between efficiency and airflow that all mechanical (media) type filters must consider.

Given the two topics above, % of particulates removed - There is a simple comparison that can be made once the two topics above are known... air cleaners that catch a large % of small (.01) particles while not restricting air flow are the best.