We test and score air purifiers using a battery of 5 data-driven tests. Our tests are a mix of objective testing and subjective assessment. This testing process applies to only air purifiers.
Our 5 testing and scoring categories include:
In addition, we also test and/or analyze the following non-scoring categories:
- Ozone
- Filters
- Coverage
- Size & Dimensions
Ozone is a special category. While we do not directly score ozone, we do conduct an objective ozone measurement test. Any air purifier creating ozone at levels of 0.1 PPM (parts per million) or higher will automatically fail, resulting in an overall override score of 0% (overriding all other performance scores) and receiving an explicit “we do not recommend this product” notice at the top of the review.
Ozone in excess of 0.1 PPM is dangerous and, in our view, has no place in any home.
Regarding filters, needless to say, filters are mission critical to any air purifier. Instead of trying to assess filter quality, we rely on the objective data from our purification performance testing to determine filter performance. As a result, the filter section of our reviews is focused more on the type of filters being used and their purpose.
Purification Test
Scoring Weight – 75%
Our purification test is an objective performance test. We put the air purifier in a ~14′ x 10″ room and introduce smoke and other particulates into the air via incense for 30 seconds. We use a professional air quality detector to measure the air quality of the room.
We run the air purifier on the highest fan speed for 2 hours, taking measurements of the air quality after 1 hour and 2 hours.
This test examines how well air purifiers can purify the surrounding air. Our air quality detector gives us readings of:
- PM2.5
- PM10
- Airborne Particulates
- Air Quality Index (AQI)
In all cases the lower the number the better the performance of the air purifier. The PM2.5 measurement determines the precise score.
Build Quality Test
Score Weight – 5%
Our build quality test is a subjective test. We examine and assess the major material and design components of the air purifier, rating the build quality of each element.
Specifically, we are looking for build and design issues that are more likely to break and/or be difficult to use. Our assessment follows our standard 7 level tier system (exceptional, excellent, very good, good, fair, poor, and very poor).
Noise Test
Score Weight – 5%
Our noise test is an objective test. We use a sound meter to measure the level of noise generated by the air purifier. We keep the meter about 3 feet away from the air purifier and run the device on the lowest and highest fan speeds. In addition, we measure the ambient noise levels of the room used as a comparison.
The noise score is based on the noise generated on the highest fan speed.
Usability Test
Score Weight – 5%
Our usability score is based on 2 factors. The 2 tests are weighted based on their relative importance.
The 2 testing and scoring factors include:
In addition, we also record the specific parts and accessories included within the box. This is a non-scoring factor.
Setup
Score Weight – 25%
Our setup test is a subjective assessment. We set up the device, recording the length of time required to set up the device as well as the difficulty of the setup process.
Controls & Display
Score Weight – 75%
Our controls & display test is a subjective assessment. We consider the overall controls and display usability, experience, and quality to determine our rating. Our assessment follows our standard 7 level tier system (exceptional, excellent, very good, good, fair, poor, and very poor).
In Box
Score Weight – 0%
Our in box test is a report of what items can be found in the box when unpacking the air purifier. Due to the this test being an itemized report, this is not a scoring factor.
Maintenance Test
Score Weight – 5%
Our maintenance test is based on 2 factors, with 1 being an objective test and the other a subjective assessment.
The objective factor is:
- Recurring Costs
The subjective factor is:
- Maintaining Tasks
Recurring Costs
Score Weight – 50%
Our recurring costs test is an objective test. We calculate the annual cost of replacing filters and mathematically determine the cost of a replacement filter in relation to the CADR (Clean Air Delivery Rate) of the device. Air purifiers that are able to cover a larger area at a cheaper price are better.
Maintaining Tasks
Score Weight – 50%
Our maintaining tasks test is a subjective test. We examine the tasks required to maintain an air purifier, taking note of their relative difficulty and time requirements. Our assessment follows our standard 7 level tier system (exceptional, excellent, very good, good, fair, poor, and very poor).
Ozone Test
Score Weight – 0%
Our ozone test is an objective test. We put the air purifier in a ~14′ x 10″ room and let it run for 1 hour. We make sure to turn on any optional filtration methods for this test. After the hour, we measure the levels of ozone in the room with an ozone meter.
While this test doesn’t contribute to the overall score, it is a critical factor. Exposure to ozone can cause headaches, coughing, dry throat, shortness of breath, and other severe symptoms . Any air purifier that generates unhealthy levels of ozone (0.1 PPM or higher) is not one we would recommend.
Filters
Score Weight – 0%
Our filter test is a subjective assessment. We consider the filter types and reported filter rating by the manufacturer.
Coverage Test
Score Weight – 0%
Our coverage test is a combination of 3 factors. We perform a wind speed test and report the coverage area and CADR if available.
Wind Speed Test
Score Weight – 0%
Our wind speed test is an objective test. We use an anemometer placed directly on the air vents of the air purifier. We measure the wind generated on the lowest and highest fan speed.
Wind speed is not a scoring factor.
Size & Dimension Tests
Score Weight – 0%
Our size and dimension test is a report of size and weight
This is not a scoring factor.