When deciding what type of window treatments to pursue, the question of horizontal versus vertical window blinds inevitably is asked. Which is more energy efficient? The answer is clear. Vertical window blinds provide more energy efficiency for several reasons.
For those who live in warmer climates, vertical window blinds better block the sunlight from peering though and seeping unbearable heat into the house. This ability to keep the sun away is a big reason that many people choose vertical blinds over horizontal blinds. While horizontal blinds try to keep the sun out, it does not get the job done. Because the sun shines downward, the sunlight easier enters into the home through horizontal blinds.
In cooler climates, vertical blinds still win over horizontal blinds. When the blinds are closed, the panes overlap one another. This overlapping action creates a highly efficient pocket between the blinds and the weather outdoors. During the cold months, it keeps the heat inside the house and the cold outside of the house. Likewise, during summer months, it works the same way to keep the cold air inside of the house and the heat outside of the home.
Because of the ability to insulate the home, the vertical blinds are much more energy efficient than horizontal blinds.