Air cleaners also known as air purifiers can be used to clean your home or office air. Why would you want to clean your air? Indoor air pollution is among the top five environmental health risks. Air can contain viruses, bacteria, mold, cat and dog allergens, dust mite allergens and more. The quality of the air can effect your health. There are different types of air cleaners and there is a way to measure their effectiveness.

How can portable air cleaners be evaluated by their effectiveness in reducing airborne pollutants? The effectiveness is measured by the clean air delivery rate (CADR). CADR was developed by the Association of Home Appliance Manufacturers (AHAM). AHAM is the most popular trade association for the home appliance industry.

The CADR is expressed in cubic feet per minute. It is the measure of a portable air cleaner’s delivery of contaminant free air. As an example you may look at an air purifier and see that it has a CADR of 250 for dust particles. What exactly does that mean? Essentially it is equivalent to adding 250 cubic feet of clean air each minute. The CADR standard of measurement allows you to compare a different portable air cleaner.


There are different types of air cleaners. The Environmental Protection Agency has an excellent Guide to Air Cleaners in the Home.

Air filters typically refer to passing air through a filter that removes particles. In your home or an office HVAC system there is typically a filter housing installed in the air ducts of the system. Often times near the furnace and other areas such as the return air vents in each room so that you can easily access and replace filters. A portable air cleaner that uses a filter has a fan to circulate air and pass it through a filter inside the air cleaner.

When it comes to air filters you may see some that meet what is known as HEPA standards. HEPA (High Efficiency Particulate Air) filters meet a Department of Energy standard for removing particles from the air. The type of material used in the filter does not matter as long as it meets the standard of less than 0.03 percent of particles 0.3 micrometers in size or larger. There is a balance between the air that flows through the filter and the size of particles it must trap.

There are many other features to consider when it comes to the different types of air cleaners. Most of the features are going to be personal choices. Here is how many differ. Some are silent and others do make noise. Often there is a fan speed controller and the faster you circulate the air the louder the fan. You can choose one that is completely silent all the time or a popular feature now is a silent mode where you do not even realize it is on. Another feature to look for are the recommended room sizes. Typically the manufacturer will tell you which size room the air cleaner is recommended for in square feet. You can use it in a smaller room or a larger room, it just effects how often the air is circulated and therefore the CADR. Another important feature is the physical size of the cleaner, some are just a foot tall while others can be three feet tall, some are square and others rectangular. While looking at the size and shape you also need to note how the air is circulated, some units are made to be placed against a wall and will not obstruct air flow, while others may need more space. So where you are going to place the purifier may determine which one you should purchase. There are other factors that you may want to consider such as the color. Overall cleaning the air can assist with allergies and more, here’s to your health.