If you’ve ever strolled into Home Depot or Walmart and purchased a set of Venetian or mini window blinds—which consist of a series of horizontal wood, aluminum, or plastic slats—you may have wondered whether the blinds should be adjusted so they’re pointing up or pointing down. If they’re convex (curved) blinds, they look more uniform pointed down. But since blinds can be adjusted, there must be some reason to want them oriented up, right? So which way should window blinds face?
It’s usually a matter of privacy. When you adjust blinds to face up with the curved part facing the interior of the space and the convex part facing the window, it’s harder for people to see inside because there’s less space between slats. If you position the blinds facing down, it may be easier for people to view the interior of the room through the spaces between the slats. (Note that if you have people peering inside your home with their nose pressed against the glass, your problem is probably not your blinds.)
Other people care less about privacy than aesthetics, and blinds facing down are neater in appearance than blinds facing up. They also let a little sunlight leak in, giving the room more natural light than if the blinds were turned up. This position can let in UV light, however, which might eventually fade certain surfaces near the window.
The time of year may also influence how you adjust the blinds. Blinds facing up let less sunlight enter the room, so you can keep it cooler in the summer by reducing heat from direct sun. In the winter, opening the blinds may help warm a room.