Filtering air is incredibly simple. All you need is a fan and a filter. In fact, they’re so simple it’s even possible to DIY your own air purifier. So that begs the question: can a filter be attached to an air conditioning unit to create an air purifier? Smart Air puts 3M air conditioner filters to the test.
3M Air Conditioner Filters: Do They Actually Work?
3M claims their ‘air conditioner filter’ filters out particles as small as 0.02 microns and can remove 83% of PM2.5 pollution in one hour. But, do these 3M air-con filters really work? And do they work in all rooms and for all air conditioners?
We set up the filters according to the instructions given by 3M, attaching them to the air conditioner in one of our rooms. Thereafter, we measured the concentration of PM2.5 particles before and after the air conditioner was turned on.
Results – 3M Filter Significantly Reduces PM2.5
There was a large decrease in PM2.5 particles from the moment the air conditioner (with 3M filter attached) was turned on at the 0-hour mark. After the air conditioner was turned off at the 5hr+ mark, PM2.5 concentration gradually rose for the following 2 hours.
More specifically, after one hour of running the air-conditioner, PM2.5 concentration reduced 87.9% from 33 μm/m³ to 4 μm/m³. This is safely below WHO recommended levels of PM2.5 of 10 μm/m³.
However, although the change in PM2.5 concentration gives us a good indication of whether the 3M filter works, measuring its CADR (Clean Air Delivery Rate) gives us more information about its effectiveness.
How Much Air Does a 3M Air Conditioner Filter Clean?
CADR reflects how much clean air is delivered to the room at a given time. Smart Air ran a CADR test on the air conditioner (with the 3M filter) and compared the results to our other DIY purifiers.
Results showed that DIY 1.1 is almost twice as effective as 3M’s filter, and the Sqair is 543% more effective! However, this does not mean that 3M filters are totally ineffective. According to AHAM recommendations, with a CADR of 49m3/hr, the 3M filter is still effective for room sizes within roughly 6 m2 (for small rooms!).
Air Conditioner Effectiveness Decreases Slightly With 3M Filter On
Smart Air also measured the wind speed of the air conditioner with and without the 3M filters attached. The average of the wind speed measurements at the three positions (as shown below) was taken.
Results showed a 22.2% decrease in wind speed when the 3M filters were attached to the air-conditioner.
However, this does not significantly affect the air conditioner’s cooling performance – Smart Air found that it is still possible to get the room temperature below 20 °C!
Air Conditioner Does Not Get Louder With Filter
Throughout the tests, there was no noticeable increase in noise when the air conditioner was fitted with a 3M filter. However, if the air conditioner sounds louder on ‘auto’ mode, it is likely because the air conditioner takes more effort to cool the room due to the 3M filter reducing its wind speed. Thus, it will run longer at a higher speed.