The word is built like a set of blocks: you take “air” (空气), add the action “to purify” (净化), and attach the suffix for a “device” (器), creating a perfectly descriptive name: “air-purifying-device.”
The 空气净化器 is more than just an appliance in China; it's a household necessity and a cultural touchstone for a specific era of the country's development. Unlike in many Western countries where an air purifier might be purchased for specific allergies or sensitivities, in China's major cities, it became a standard home fixture during the 2010s due to widespread air pollution, known as 雾霾 (wùmái), or smog. Its presence in a home, office, or school signifies a proactive approach to health and a desire for a better quality of life. The decision to buy an 空气净化器 is often driven by the daily 空气质量指数 (kōngqì zhìliàng zhǐshù), or Air Quality Index (AQI). A high AQI reading on a weather app directly translates to windows being closed and purifiers being turned on high. This appliance is a tangible, daily reminder of the connection between industrial growth, environmental impact, and personal health, representing the concerns and aspirations of China's growing middle class.
The term 空气净化器 is used in a variety of everyday contexts. It's a standard, neutral term appropriate for all levels of formality.
The connotation is generally neutral-to-positive. While its necessity points to a negative problem (pollution), owning one is seen as a responsible and health-conscious choice for oneself and one's family.