Stuck in the fan room

[Atomic_Piggy]

after this room: http://img463.imageshack.us/img463/594/hl22007101611331921xg0.jpg

There is a room with a fan, none of the surfaces of which actually respond to portals. Please help!

EDIT: Hag I'm retarded. FOund out how to get through by sheer accident

 

[Pi Mu Rho]

The window responds to a rocket...

 

[Ridge]

The window responds to a rocket...

LOL!!!