The Dyson Global Connected Air Quality Data project analyses more than half a trillion data points to paint a picture of the air quality in real homes around the world, understand user behaviors and compare indoor and outdoor air quality. The indoor air quality studied is based on the location of Dyson purifiers in homes and as such is not nationally representative.
Indoor air quality data is taken from Dyson purifiers that are connected to the MyDyson app and in monitoring-only mode – that is, not actively purifying the space. Whilst this reduces the sample size for the calculation, Dyson data scientists can be confident that it is an accurate representation of air quality in real homes, without the impact of Dyson purifiers actively cleaning the air.
- From a wealth of data, Dyson data scientists have focused on PM2.5 and VOC data, analysing the measurements from 1st January to 31st December 2022. Data is collected by the machines every 1 minute, which is time-averaged into averages by hour, day, month, season and year depending on the calculation in question. For all the mean estimates, we consider the 99% credible interval to ensure accurate, statistically significant spatial and/or temporal comparisons.
- Outlier machines have been removed as part of data cleansing. For example, machines that are showing extremely high particle pollution in a region where this trend is not reflected across the board, may have a blockage in the sensor which might skew the data readings. These types of outliers have also been removed. A machine “in Auto mode” is determined by it spending >75% of each day in the year in Auto mode. This allows for ~6 hours of the day on manual, which would account for it being used manually in heating or cooling mode.
- Machines are not all on for 24 hours a day, for every day of the year. As such, machine data is weighted in line with the proportion of the given time-frame that each machine is on, connected to the MyDyson app and recording data. For example, if a machine is only connected to the MyDyson app for 6 months of the year, the machine would be weighted less than a machine connected year-round.
Outdoor air quality data is sourced primarily from OpenAQ, and from the World Air Quality Project in Shenzhen, Fukuoka, Osaka, Amsterdam and Taipei.
Countries studied (39): Australia, Austria, Belgium, Canada, China, Czechia, Denmark, Finland, France, Germany, Greece, Hungary, India, Indonesia, Ireland, Israel, Italy, Japan, Malaysia, Mexico, Netherlands, New Zealand, Norway, Philippines, Poland, Portugal, Romania, Saudi Arabia, Singapore, South Korea, Spain, Sweden, Switzerland, Thailand, Turkey, U.A.E., U.K., U.S.A., Vietnam
Cities studied (44): Amsterdam, Bangkok, Beijing, Berlin, Bristol, Brussels, Busan, Chicago, Cologne, Copenhagen, Delhi, Dubai, Dublin, Fukuoka, Hanoi, Hong Kong SAR, Istanbul, Jakarta, Kuala Lumpur, London, Los Angeles, Lyon, Madrid, Manchester, Manila, Marseille, Melbourne, Mexico City, Milan, Mumbai, Munich, New York, Osaka, Paris, Rome, Seoul, Shanghai, Shenzhen, Stockholm, Sydney, Taipei, Tokyo, Toronto, Vienna.
