Dumb question about window screens

[scab]

When I moved into my current home seven years ago, the majority of the window screens were being stored under the house instead of on the windows. I don't really ever open my windows throughout the year so I just left them there. So my really stupid question is, do window screens serve a purpose other than keeping insects and whatnot out of your house when the window is open? They seem to always collect a lot of dirt and debris in between the screen and the window so they seem silly unless you happen to cool your house with fresh air in the warmer months. Am I missing something here?

 

[Stuart in MN]

If you never open the windows, there's no reason to put the screens on. They're mainly for keeping bugs (and birds and bats and any other critter) out if the windows are open.

 

[radrush]

They seem to always collect a lot of dirt and debris in between the screen and the window so they seem silly unless you happen to cool your house with fresh air in the warmer months.

Screens that fit properly should not have a buildup of debris in between the screen and the window.

 

[ihatelaramie]

Another note, depending on the opacity of the screen, it may provide a halfassed shading effect.

 

[volvo]

..
If you check a real window/screening store they now have about five different types of screening materials, ranging from cheap looks like **** that discolors & wears out to heavery material that you actually do not notice as much. Pretty interesting if you haven't seen them before at a reasonable price points.