Air purifiers are most effective when all doors and windows are closed. This allows the air purifier to clean the air in the room without interference from corridors or other rooms. No one doubts that purifiers are more effective with closed windows. Tests carried out under real conditions show that, even without an air purifier, simply keeping doors and windows closed keeps particle pollution levels at 50% of the level of outside air.
Therefore, when using an activated carbon air purifier to purify smog, there is no need to open the window, but when purifying air pollution from the decoration, the window must be opened, since activated carbon can only absorb a small amount of decorative pollutants. By continuously circulating clean air in a space, an air purifier is more effective with the windows closed. It is best to open windows and doors when the air purifier is not working, as it will promote the circulation of fresh air and, at the same time, eliminate particles and smoke from indoor air when cooking, dusting and smoking. The effect of having the window open on indoor air pollution levels will be more evident when outdoor air is dangerous, so CK chose two days when outdoor air pollution was bad (February 14 and 15) to carry out its tests.
It is necessary to open the window when using the air purifier, since most air purifiers are not very effective at purifying formaldehyde. So can you use an air purifier with the windows open? Will opening the window to use the air purifier reduce the air purifying effect? To keep the reference level of contamination consistent across all tests, CK opened the window to let in outside air (and outdoor air pollution) until the particulate pollution was the same as that outside. In addition, keep a close eye on the filter when using an air purifier with the windows open, as it becomes less efficient at cleaning the air in your house when the filter becomes clogged with pollen or others airborne pollutants. While some air purifiers are designed to work best when exposed to fresh outdoor air, make sure your air purifier is designed for outdoor use if you open a window while it's in operation.
In addition, another drawback of using an air purifier with the window open is the limited purification capacity and space of each air purifier. If the living environment is close to the road and it is not convenient to open the window, you can also activate the air supply mode of the electric fan or air conditioner and use it with NCCO.
