Not all purifiers are equal. Getting the right size purifier, with the best projection is essential to ensure it will effectively purify the air in your space. We've tested the Dyson Purifier Big+Quiet  Formaldehyde extensively – to ensure the sensors, filtration system and motor work together to purify a large living space. It has the projection power to purify spaces up to 100m². The Dyson Purifier Big+Quiet Formaldehyde also has our largest ever filtration system – and the 360° HEPA H13-grade filter doesn’t need replacing for up to 5 years.