Price (RRP): $949 but great bargains if you shop around
The Philips Air Purifier series
We have been testing a Philips Air Purifier series 3000. It has made a profound difference to the office environment. Hay fever suffers rejoice!
Why do we need an air purifier?
The air we breath has a level of pollutants – it is not just good old pure air – (%) nitrogen, 78.084; oxygen,20.946; argon, 0.934; carbon dioxide, 0.033; neon, 0.0018; helium, 0.000524; methane, 0.00016; krypton, 0.000114; hydrogen 0.00005; nitrous oxide, 0.00003; and xenon, 0.0000087 anymore.
In Sydney – like any major city – the air carries pollutants. These include sulphur dioxide, carbon monoxide, nitrogen dioxide, ozone, large particulate matter (PM10) to small (PM2.5) particles. You can view this on an hourly basis at the NSW Air Quality Data website (or the equivalent site in your state).
As I write (27 November) most of the state was in the Blue – very good. Over the weekend when there were fires in Newcastle that sent air quality up to Very Poor. During the major dust storm last week, it went to Hazardous.
If you suffer asthma, hay fever, watery eyes or allergies, then the past couple of weeks would have been hell. We won’t go into these 21-century ailments suffice to say that I would not live in Beijing for all the anti-histamine in the China (and I like Beijing apart from its air).
How purifiers work
Most have filters. The more expensive ones use HEPA (high-efficiency particulate air) and active carbon. Lower-cost, lower efficiency ones use paper or fabric filters.
The Philips Air Purifier has a washable pre-filter to remove large particles (like in most split system air conditioners). Then an active carbon filter to remove potentially harmful gases such as TVOC (volatile organic compounds), smoke and odours. Finally, a HEPA filter removes ultra-fine particles as small as 0.002um, including allergens, dust and dust mites.
Air is drawn into the unit and comes out gently as cleaner air.
How is purifier capacity measured?
One cubic meter of air is 1,000 litres. Reputable purifier makers will quote a CADR (clean air delivery rate) in m3/hour.
How do you know a room cubic meterage? Well, it is length x depth x ceiling height. Of course, you need to consider whether that room can be enclosed (like a bedroom with a door and windows) so it is a closed ecosystem. Or if it is more open (like an open plan lounge/dining/kitchen with perhaps a hallway and stairwell to other levels), then it is an open ecosystem.
The rule is that you always over-order CADR capacity for open space and you can get away with a little less for closed spaces.
Review: Philips Air Purifier AC3256 (Philips 3000 series)
There are three Philips Air Purifier series – 2000 (for up to 70m3 rooms or 5 x 5x 3m), 3000 (up to 95m3 – 5 x 6 x 3m) and 6000 (up to 130m3 – 7 x 6 x 3) room sizes. Of course, these room sizes are nominal – the key issue is how closed the ecosystem is.
Philips quote a CADR rating on the Series 3000 of 367m3 per hour – 367,000 litres. To put that in perspective a small bedroom of 3 x 3 x 2.7m is 24.3m3 – it can turn over the air 15 times in one hour!