Why does the windowsill get dirty so fast?

Why doesn’t the insect screen help?

The holes in a standard insect mesh are small enough to stop mosquitoes, but dust grains are many times smaller. That is why even a window with an insect screen soon has a dark windowsill. For details, see the dustproof insect screen page.

What can you do?

1. Open the window early in the morning or late in the evening, not at rush hour.
2. Wipe the windowsill with a damp cloth rather than a dry one; a dry cloth lifts dust into the air.
3. In place of the insect mesh or directly on the frame, fit a window filter. The nanofiber membrane lets air through and holds back most of the dust.