Window film or heat blocking shades?

[quakerboy]

12. Depends on the goal

For light blocking, window film. For heat blocking, insulating shades.

We use a blackout window film for the bedroom. I like a dark dark place to sleep. It works great for that.

But it turns the window into an oven. It radiates a huge amount of heat into the room. On a hot sunny day, it gets hot enough you cant really touch the window. Hot enough that it cracked the inner pane of the window. Even on a cool day, it radiates an uncomfortable amount of warmth into the room if the sun is out. We have resorted to putting a sheet of styrofoam in between the window and the blinds, which seems to block most of the heat.