BEIJING - With the capital mired in the depths of its smoggy winter days, air purifiers are becoming a hot item among those wishing to breathe easier.

Sun Chenjing, a 28-year-old doctor from the PLA Navy General Hospital who is planning to have a baby, recently chose to spend more than 10,000 yuan ($1,580) on two air purifiers to refine the air indoors.

A customer discusses air purifiers with a saleswoman at a chain store of domestic retailer Suning Appliance Co Ltd in Beijing late last month. [Photo/China Daily]

"I don't want my baby to fall prey to the city's pollution," she said.

Sun is just one of many Beijing residents who are buying air filters in droves. According to Gome Electrical Appliances Holding Ltd, China's second-biggest electronics retailer by revenue, the sales of its air purifiers in Beijing since June grew by 80 percent compared to the first half of the year, and it marked a 60 percent year-on-year increase.

Because of the lingering concern over smog and pollutants, the sales of air purifiers and other air cleaning products, including masks and humidifiers, have skyrocketed since November.

Zhai Lei, an agent who sells air purifiers for Amway in Beijing, said sales of the high-end model have doubled since November despite the fact that the price rose from 8,800 yuan to 9,300 yuan during that same period. The sales volume rose from 22 billion yuan in 2010 to 26 billion yuan in 2011.

Zhai said target clients are mainly white-collar workers and enterprise managers and executives, who attach great importance to quality of life and can afford what may be considered a luxury to some.

"Many people also purchase batches of machines as holiday gifts as Spring Festival approaches," Zhai said.

The upsurge of air purifier sales comes at a time when the capital has been persistently under a canopy of dense smog.

Sun said the two machines, which she placed in the bedroom and lounge, have been functioning pretty well.

"You can simply sense the fresher air you are breathing," Sun said. "And my husband, who has been suffering from the chronic pharyngitis and rhinitis, also felt much better when he came back home."

He Bing, deputy dean of the law school at China University of Political Science and Law, said he found ink-colored, dirty water after cleaning the soot-laden filters in his air purifier, which has only been working for 10 days.

And Bei Zhicheng, a software businessman in the capital, has recently spent more than 10,000 yuan installing a ventilation system and purchased seven air purifiers at home, in the office and the car. "The city's air is getting more soupy," Bei said.