Which one should you consider buying?
It depends on what purpose you need it for and the room size. Why is that because a certain room or location of the space affected the sensitivity of airflow? To make it more precise, the humidity of the room level plays a leading role in which product to buy.
First, you will need the humidifier sensor that will determine the room’s dry or wet atmosphere. A small sensor will relieve the pain of guessing which products to get. Plus, there are multiple humidifier sensors and there are multiple options to choose from as well.
Second, with the humidifier sensor in mind, the room will adjust to the temperature and need what is missing from the room. An air purifier removes unwanted air from the room to purify the indoor air quality. For example, if it is a hot humid day the air purifier will pull all the dirty particles from the air to circulate and improve the room quality to make you breathe better. An air humidifier is recommended used when the room is dry or completely dry. It will improve the air quality to make your skin or breathing easy. In winter or when it is cold the air humidifier will be used most.
In theory, you will need both an air humidifier and an air purifier. It will moisturize the air quality in the room, make you breathe better, and especially during sleeping at night.
Check out Air purifier and
Air humidifier