As a nation, we are challenged each summer to prevent buildings from overheating. The Climate Change Committee claims millions of homes, commercial buildings and hospital wards are overheating during summer, attributed to climate change and the unintended outcome of insulating buildings to conserve energy during winter. Evidence suggests that overheating not only leads to discomfort for residents but can also harm their health. 

Do blinds keep heat out? 

Blinds can help keep us cool, offering not just privacy and control over the amount of natural light that enters a room but also impacting thermal comfort and energy efficiency. Blinds act as a barrier between the indoor environment and the window, which can become a significant source of heat gain during warmer months.  

By blocking and reflecting sunlight, blinds reduce the amount of heat that enters a room. If the blind and fabric are effective in blocking the sun, this can lead to a reduction in the need for air conditioning, contributing to lower energy bills and a more comfortable indoor climate. 

A review of different blind fabrics  

The type of fabric and its colour greatly affect a blind’s ability to keep heat out. Generally speaking, the thicker the fabric, the more efficient the blind will be in reducing solar heating. Screen fabrics are designed to let more light in than any other type of fabric, so if an end user’s goal is to prevent the sun’s heat from entering, dimout or blackout fabrics are better solutions. Blackout fabrics are the thickest, meaning heat finds it more difficult to transfer through the material. 

Reflective blind fabrics are designed to reflect sunlight and heat away from the window. Light-coloured fabrics are more effective at reflecting sunlight, while dark colours tend to absorb it, potentially increasing heat gain. We offer a selection of white-back fabrics, which are more reflective and attract less sunlight. 

Window sun transmittance smaller 604pxHere’s a quick summary of the science behind reflective fabrics and white backing: 

A black object absorbs every wavelength of light and reflects none, which results in the object warming up. Conversely, a white object reflects every wavelength of light, preventing the light from being transformed into heat and, as a result, the object's temperature does not rise significantly. Therefore, a white backed fabric is ideal for south-facing windows.  

Do all blinds keep heat out? 

Certain types of blinds are better than others when it comes to thermal performance.  

Honeycomb blinds:  

Also known as cellular shades, honeycomb blinds are highly praised for their insulation properties. Their unique design, consisting of layers of fabric formed into cells, traps air within those cells, providing a barrier that helps keep heat out in the summer and retain warmth in the winter. 

Roller blinds:  

With the right reflective material, roller blinds can serve as a good option for heat control. They offer a sleek, minimalistic design and can be effective when fully closed. Cassette blinds are roller blinds with side channels which ensure there isn’t a gap either side of the fabric for heat to come through. A cassette blackout blind benefits from the side channels and thick blackout fabric with solar reflectance. 

We supplied overhead roller blinds to a cafe which was having problems with the sun making staff feel too hot while making drinks and serving customers. You can read about the installation here

2 3178 (1)

Do vertical blinds keep heat out?

Vertical blinds have gaps between the louvres, which allow hot air to pass through. Despite this, a vertical blind will still help to moderate room temperature to an extent. Similarly, venetian blinds have gaps between their slats, which air can pass through. Neither system can prevent solar heating as efficiently as a blind with a single piece of fabric, such as a blackout blind.

To ensure that blinds are as effective as possible in keeping heat out, ensure that blinds are installed as close to the window glass as possible to minimise heat transfer. The fit should be tight to prevent heat from entering around the edges. 

Keep cool this summer with Yewdale’s commercial blinds 

Blinds can be an effective tool in keeping heat out of a building, contributing to both comfort and energy efficiency. The key to maximising their effectiveness lies in choosing the right type of blind and fabric and installing the system correctly.  

We design and produce commercial blinds which are not only thermally efficient but also fire retardant and child-safe, ensuring compliancy with building regulations for commercial and public settings. Our team hand-craft flawless blinds in short lead times, supplying them directly to the people who install them.  

If you require any additional information, we’re on hand to help you. Just click here to reach out to us or call us on 01268 570900.