Air Purifier Systems and MERV

Shopping for an air purifier can be like communicating with the government, you will hear all kinds of acronyms. Here’s what one that has begun appearing on purifier packaging recently is all about.

You may be familiar with CFM (Cubic Feet per Minute) and CADR (Clean Air Delivery Rate), but MERV is an acronym that is just now appearing on some air purifier products. It can be found on the Trion electrostatic purifier that ClearFlite is now carrying. MERV stands for Minimum Efficiency Reporting Value. It is reportedly a “rating” that tells you how good a filter is. It has been used in reference to a whole variety of filters used in air purifier devices, furnaces, and air conditioning. From the purifier or filter manufacturer’s point of view, MERV is a commonly used rating system for filters that describes how well they perform in removing particles from the air in a room. The higher the MERV rating the filter receives, the better the filter performs the job of filtration.

From a technical point of view, however, MERV isn’t really a rating for an air purifier. A MERV value is established through a method of testing which is described according to ANSI/ASHRAE Standard 52.2 specifications. (ANSI is a federal agency – the American National Standards Institute). MERV is not officially a test of quality; it’s essentially a measure of the average initial efficiency by particle size of a filter when tested at a specific velocity. It’s really designed for professional IAQ (indoor air quality) technicians to pick the appropriate filter removal efficiency for a particular size particle that the professional is trying to make sure gets eliminated. If all that is confusing or boring, the bottom line is that when a manufacturer claims that MERV is a sign of quality in its air purifier, the MERV rating is really not designed to specify that.

At ClearFlite, we always try to sift through manufacturers’ specifications and claims, so that we understand the facts and can recommend an air purifier which we know to the best of our ability and experience will work in a particular application. Each of our staff members have a variety of the air purifier models that we sell in their own homes so that they can judge for themselves whether or not they truly work as claimed. More importantly, we invite feedback from our thousands of air purifier customers on whether or not the air purifier models they purchased from ClearFlite actually helped with their problems. We like to hear the answers to these kinds of questions: Do you wake up less congested? Has the paper dust in your office diminished? Do you feel healthier with the second hand smoke you were breathing removed? Has the formaldehyde that was bothering you been removed by the air purifier so that you’re not getting headaches?

The newspaper for the professional Indoor Air Quality association thinks that manufacturers are in somewhat of a race to show higher MERV ratings, and that they might be stretching the realities a bit. We will keep a close eye on this development as we take on more air purifier brands, like the inexpensive Trion line, which indicate a MERV rating on the air purifier box. We will keep an evaluation of the situation as it relates to reality on our website.