DS's bedroom suffers from a bad case of solar gain when we are out all day. Tried shutting curtains that have blackout lining but the heat is still entering the room and making it 25+ degrees plus in the eve until the sun goes down (32 last year!). Has anybody bought reflective film to fix to the window to reduce the solar gain? Quite a few websites marketing it but not too sure of price. Just trying to find alternative to buying air con unit for his room. The size of the window is about 1.2m x 1.2m with a window light of 1.2 x .25m high.