空气净化器除甲醛分为主动式和被动式两类。
In addition to formaldehyde, air purifiers are divided into two categories: active and passive.
主动式：对空气中释放负离子，负离子能够主动出击，寻找空气中的污染颗粒物，与其凝聚成团，然后将其沉降。
Initiative: release negative ions to the air, negative ions can take the initiative to attack, search for particulate matter in the air, coagulating them into clusters, and then settling them.
被动式：大多采用风机+滤网的模式进行空气净化，有一定的局限性，只能在空气净化器的周围产生一定的净化效果，需要很长时间才能将室内空气全部过滤一遍。
Passive: mostly using the fan + filter mode for air purification, there are certain limitations, only around the air purifier to produce a certain purification effect, it takes a very long time to filter all the indoor air.
空气净化器对于可吸入颗粒物以及异味相对有效，使用也相对方便，但对于彻底清除甲醛作用不是特别明显，价钱一般都会稍微偏高，可以使用，但在性价比方面值得考虑。
Air purifier is relatively effective for inhalable particles and odor, and it is relatively convenient to use, but it is not particularly obvious for the complete removal of formaldehyde. The price is generally slightly higher and can be used, but it is worth considering in terms of cost performance.