Panasonic F-PJD35A air purifier

I've always wanted an air purifier. I think dirty air is underestimated. I've tried a few cheap air purifiers but they were useless, so don't waste your money. The good ones are about $400 onwards, but I didn't want to buy one with no way of measuring how good they were. I saw this on sale at half price ($299), so I decided to finally try one.

Basically, it's a filter and a fan, with a nano/ion generator. Personally, I don't really like ions from air purifiers because I'm not sure what they do. The brochure for this has reports saying their ions kill viruses/bacteria.

This is the front of the main filter

Back.

The second, deodourising filter. It has a very interesting structure, like black crystals grown on a grid.

At full power, it uses 32W. At minimum power, 6.5W. Maintenance: vacuum the front of the main filter (black) once every 2 weeks. Filters last 2 years.

• It seems to be on its way out. Panasonic's Singapore and Malaysia websites have no air purifier section, although the model shows up on their website on Google searches. I had a hard time finding the manual online, and finally found it on the Hong Kong website.
• Has dust sensor, and can automatically control its power according to amount of dust.
• Sensor sensitivity can be adjusted
• Quite quiet and uses little power
• Long filter life
• No HEPA
• Filter frame is made of cardboard, I read this may lead to poor sealing and air bypassing the filter, but looking at the dust accumulated this doesn't seem to be a problem.
• I'm afraid I'll drop something into the vent on top and it'll destroy the fan. I hope the fan isn't directly beneath the vent. All the other air purifiers I've seen also have the vent on the top.

 After 2 weeks, there is a visible layer of dust, although it's hard to see in this picture.

Sharp's air purifiers using Plasmacluster are quite famous. I found Plasmacluster works by splitting water molecules into H+ and OH- ions, which deactivate viruses and bacteria. According to Panasonic, "a nanoe is a fine (5 to 20 nm) and weakly acidic water particle with a reactive substance and an electric charge", "nanoe comes from condensed moisture in the air". I wonder if they're similar?

If I were to get another air purifier, I'd look for:

• HEPA filtration
• UV disinfection (I trust it more than nanoe)