Made to measure: hook-and-loop or roll
How do they work?
Air purifier uses a fan to draw in the room’s air, pass it through a filter and return it to the room. It works best with the windows closed. It runs on electricity, and its filters need replacing at intervals.
Window filter is a passive filter fitted to the window. It uses no fan or electricity. With the window open, it holds back dust, pollen and tiny insects in the air coming in from outside. It is cleaned by washing.
Comparisons
| Air purifier | Window filter | |
|---|---|---|
| How it works | Filters the room’s air over and over | Filters the air coming in from outside |
| Window | Effective when closed | Used when open |
| Electricity | Needed | Not needed |
| Noise | May have fan noise | Silent |
| Care | Filter replacement | Washing |
| Dust formed indoors | Reduces | Does not reduce |
| Dust and pollen from outside | Load increases if the window is open | Holds it back at the window |
| Fresh air | Does not provide | Provides |
