Recently published research has found that Venetian blinds can lead to an indoor air temperature drop of 8 degrees Celsius on hot days, and that increases in temperature are directly related to the amount of sunlight that enters a building.
The study, published in the journal Recent Trends in Civil Engineering and Built Environment, brings together the results of 20 previous papers, and focuses particularly on external Venetian blinds as a way to reduce indoor heat levels.
In their analysis, the researchers write: "It was found that the introduction of external Venetian blinds with at least 40 degrees of slat angle can produce heat reduction of 8C."
They add: "The relationship analysis shows that there was a moderate to strong correlation between the indoor air temperature and illuminance level."
While it is not surprising that allowing more sunlight into a room increases its temperature, the research demonstrates the significant effect that Venetian blinds can have to mitigate this.
How do window blinds reduce heat?
Window blinds can reduce indoor heat levels in several ways. The angled slats of Venetian blinds can be adjusted to reflect as much sunlight as possible, preventing thermal energy from entering the property.
At the same time, Venetian and vertical blinds can still have an aperture, to allow the desired amount of natural light into the room.
By angling this aperture away from direct sunlight, the natural light that enters can be diffused, with less heat coming into the room as a result.
For a maximum effect, the blinds can be fully closed, providing a physical barrier against both light and heat from the sun, and keeping interiors cooler during a prolonged heat wave.
Best window blinds for heat reduction
All window blinds will reduce heat to an extent, but some are more effective than others, so if you're keen to keep your interiors as cool as possible, here are some of the best options:
Cellular blinds
Cellular blinds have a honeycomb structure, which creates a thermal barrier when the blind is closed. This not only keeps heat out in summer, but also helps the room to retain warmth overnight in winter, to reduce heating bills.
They're a great option all year round, with a natural insulating effect and a wide choice of fabrics to make your blinds your own.
Blackout blinds
Blackout blinds use fabrics that prevent light from passing through. Though there will be some light ingress around the edge of the fabric, they're still a popular choice if you need darker rooms in daytime, for example if you need to sleep during the day.
By reducing the transmission of sunlight into the room, blackout fabrics for window blinds of all types can also prevent excess heating, making them a win-win for summer heat waves.
Urban shutters
Louvolite Urban Shutters are vinyl window shades that offer effective sunlight control in summer and again, provide insulating properties during winter months.
Striking and contemporary, window shutters reduce excess heat, retain warmth on cold days and offer exceptional privacy, making them an excellent all-around option no matter the time of year.