WHO CLEANED UP IN OUR PURIFIER TRIAL?
To put the devices to the test, we sprayed five squirts of deodorant in their vicinity, to mimic high levels of pollution, and recorded how quickly they responded and how long they took to clear the air.
DYSON HEPA COOL FORMALDEHYDE £499.99, dyson.co.uk
IN ADDITION to a HEPA filter and activated carbon filters – an absorbent material that mops up additional fine particles the HEPA might miss – this device contains a catalytic converter similar to the one found in a car’s exhaust. Dyson claims that this removes formaldehyde gas from the air.
‘Formaldehyde is emitted by industrial glues and paints, chipboard and other building materials, and as it’s a gas it wouldn’t be trapped by a HEPA filter,’ says Prof Lewis.
We asked Dyson for more detail about their converter but they were tight lipped.
Catalytic converters in cars work by channelling toxic exhaust fumes, such as carbon monoxide, through a honeycomblike structure made from a metal such as platinum. The metal is heated and this triggers a chemical reaction, turning the gasses into harmless water vapour and carbon dioxide.
‘I suspect it’s something similar,’ says Prof Lewis. Dyson claim this device – which doubles up as a cooling fan – can purify a large 870sqft room – the size of a twobedroom flat – nearly 13 times an hour. Prof Lewis says this might be overkill ‘unless you’re really seriously affected by allergies’.
In the deodorant test it reacted instantly, showing on the display a rising ‘score’ for PM2.5 – and it cleared the air in under two minutes. The HEPA+Carbon filter costs £65 and needs changing every 12 months, based on average use of 12 hours a day.
BLUEAIR HEALTHPROTECT 7470i £749.99, currys.co.uk
THIS contains Blueair’s HEPASilent filter, which the company says delivers 50 per cent more clean air than traditional HEPA filters.
It also has an activated carbon filter and a ‘charged’ filter similar to the one in the DustMagnet below.
Independent lab tests found the purifier was able to remove 99.99 per cent of airborne Covid particles, which the firm says is a first in the air purifier market.
It can be controlled via an app – the Dyson, Philips and DustMagnet can too – and has sensors to detect changes in air quality that trigger the device to work harder.
Blueair is a Swedish company that makes nothing but air purifiers, and this one is impressive in action. The purifier can change the air nearly five times an hour in a room that is 409 sq ft – the size of a standard two-car garage.
In the deodorant test the HealthProtect turned on full power immediately – although the fan remained whisper-quiet – and returned the air quality to excellent in under a minute.
The display tells you in detail just how clean (or dirty) the air is at any point.
The filters, which cost £99, need replacing every six to 12 months. A warning light indicates when this is due.