How does a $550 Dyson TP04 air purifier compare to the Sqair, which costs less than a third of its price? We put both air purifiers to the test to compare their effectiveness in reducing PM2.5 in the Smart Air India office in Delhi.
The Head-to-Head Test
To compare the effectiveness of the Dyson and Sqair, the Smart Air India team tested both purifiers in the 500 ft2 (46m2) office in Delhi. Here’s the room with the Dyson TP04 ready for testing:
Each purifier ran on high overnight from 10 pm until 6 am each day for over a week. We used an AirVisual air quality monitor to measure how much particulate (PM2.5) the air purifiers removed from the air at the start of the test versus the average during the final four hours.
Purifier Test Results
Overall, the Dyson Pure Cool TP04 reduced PM2.5 in the office by an average of 49% over the course of the tests.
In contrast, The Sqair reduced PM2.5 by 75% on average over the 10 days.
Sqair vs. Dyson: Daily PM2.5 Reductions
Below are the data for the PM2.5 reductions of each air purifier on each test day. The data shows the reduction in PM2.5 from levels before turning on the purifier to the average levels during the final four hours.
The Dyson reduced PM2.5 levels by more than 50% on 3 of 9 days.
The Sqair reduced PM2.5 levels by more than 50% on 9 of 10 days.
Additionally, the Dyson only reduced PM2.5 by more than 50% on 3 of 9 days, while the Sqair did on 9 of 10 days.
Comparing Days with Similar Outdoor Air Pollution
Real-world tests are great because they reflect actual conditions. But they are also less controlled than lab tests. Based on our prior tests, we know that all air purifiers perform worse when outdoor air is more polluted.
One way to get around this problem is to compare tests with the same outdoor air pollution. The Sqair reduced PM2.5 by 75% compared to 55% for the Dyson.
Note, the Sqair was even at a disadvantage when it came to outdoor air quality on the day in the above comparison. The Sqair ended the tests with outdoor air quality levels 18% higher than the Dyson, but still outperformed the Dyson by 20%.
Official Lab Tests Back Up Findings
The test results should not be too much of a surprise knowing the official lab specs of the two air purifiers. In the air purifier industry, CADR (Clean Air Delivery Rate) measures how much clean air a purifier produces per hour. Dyson’s Pure Cool TP04 has a published CADR of 164.3 m3/hr, while the Sqair generates almost double the amount of clean air per hour with a CADR of 315 m3/hr.
As part of Smart Air’s open data pledge, the test data from the Sqair and Dyson room test is openly available to download.