With COVID-19 sweeping Hong Kong, we are doing everything we can to slow down the spread of the virus. Apart from taking care of our personal hygiene and avoiding crowded spaces, indoor air quality is another area that we should pay extra attention to. A growing number of people are buying air purifiers in recent years to protect the health of themselves and their families. The increase in awareness has seen an increase in various air-purifying products—large, mini, portable and countless new bacteria-killing technology that you’ve never heard of, making picking an air purifier a daunting and confusing task for many.

Jevons Hui, assistant manager at Shun Hing Electronic Trading Co Ltd, points out that air purifier models from different brands feature a wide range of sizes, functions and technology, therefore consumers shouldn’t just use price as the only benchmark for comparison. Ultra-mini air purifiers (some of them can be worn around your neck!) have recently emerged in the market, Hui says that although he doesn’t want to make generalisations about their effectiveness, many small-size air purifiers clean the air by releasing a steady stream of ions but do not have filters, and even for the ones that do, the filters are usually too small to make any notable difference, not to mention that these tiny models are limited in the area they emit ions to. He concludes that to effectively remove viruses and bacteria from the air, larger purifiers are definitely the more reliable choice.

Brand and model

Panasonic Humidifying nanoe® Air Purifier (F-VXK70H)
Series 3000i
Philips Series 3000i Air Purifier

HITACHI Air Purifier EP-NZG70J
HD PCI Air Purifier

retail price*
$4,980 $4,988 $4,990 $4,680

Applicable area

28–48m² Approx. 52m² 62m²

Price certainly is an essential criterion when purchasing an air purifier, but there are other factors that are equally important to consider, including an often forgotten factor—the applicable area, which is the indoor space that a given air purifier can cover. “But it’s not like the higher the price, the bigger the applicable area,” Hui explains. “The price is also dependent on the functions of the product—for example, its bacteria- and virus-killing technology, the effectiveness of its filter and its power efficiency.”

Brand and model
Panasonic Humidifying nanoe® Air Purifier (F-VXK70H)
Philips Series 3000i Air Purifier HITACHI Air Purifier EP-NZG70J SharpFX-J80A-W
HD PCI Air Purifier
Nanoe technology
HEPA Composite Filter
Infrared human sensor
Humidifying function
Vitashield IPS and
Aerasense air technology
NanoProtect Pro S3 filter  

Allergen-free,  deodorising HEPA Filter
Automatic PM2.5 sensor
Humidifying function

Plasmacluster ion technology
HEPA Filter  

Depending on the brands and models, air purifiers feature different air-cleaning technology. The most advanced technology available at present is nano-ion technology, which enables the air purifier to release nano-ions into the air to inhibit the growth of viruses and bacteria. Before making a decision to buy an air purifier, consumers should find out whether the brand has run professional tests on the model’s antibacterial capabilities, and if a product has been proven to effectively filter E.coli, bird flu and other flu viruses. However, it’s worth noting that due to the lack of formal testing, it remains unknown whether air purifiers can filter and remove the COVID-19 virus.

Brand and model
Panasonic Humidifying nanoe® Air Purifier (F-VXK70H)

Philips Series 3000i Air Purifier
HITACHI Air Purifier EP-NZG70J SharpFX-J80A-W
HD PCI Air Purifier

Dimensions (mm)
636 (H) x 398 (W) x 245 (D) 698 (H) x 366 (W) x 251 (D) 669 (H) x 360 (W) x 254 (D) 728 (H) x 416 (W) x 291 (D)

Compared to their small-sized and portable counterparts, large air purifiers have the disadvantage of being bulky and tricky to place in small Hong Kong apartments. “The location of your air purifier should depend on the design of its air inlet and outlet,” Hui says. “If they are located on the back of the machine, then it cannot be placed against the wall, which can be rather inconvenient.” He adds that most air purifiers nowadays boast high power efficiency, so users don’t need to worry too much about the electricity usage. He also recommends cleaning the air filter—the most vital part of the purifier—at least once every two weeks, and replacing it with new ones whenever needed, to ensure the effectiveness of the air purifier.

*All prices are for reference only. In case of any inconsistency or discrepancy, prices listed on the company websites shall prevail.