Do Blackout Blinds Keep the Heat Out?
When the temperature rises and sunlight pours in, many UK homeowners look for effective ways to cool their interiors. One common question is: do blackout blinds keep the heat out?
The short answer is yes, to an extent. While blackout blinds are mainly designed to block light, they can also help reduce indoor heat – especially when used correctly.
How Do Blackout Blinds Work?
Blackout blinds are made with thick, opaque fabrics designed to block out all external light. This makes them a popular choice for bedrooms, nurseries, and media rooms.
But the same properties that make them great for darkness also give them potential as heat reducing blinds.
Key Features:
- Multi-layered or foam-backed materials
- Light-blocking linings
- Tightly fitted frames or side channels to prevent light (and heat) leakage
Do Blackout Blinds Actually Keep the Heat Out?
Blackout blinds can reduce solar gain – the process by which sunlight heats up a room—by blocking direct sunlight from entering through the window.
However, the effectiveness depends on several factors:
Factors That Affect Heat Reduction:
- Colour of the blinds – Lighter colours reflect more heat, darker ones may absorb it
- Material and backing – Thermal or reflective linings boost heat resistance
- Installation quality – Well-fitted blinds block more heat
- Window type – Single glazing allows more heat in than double or triple glazing
While not as effective as external shading or reflective blinds, blackout blinds can contribute to a cooler room, particularly if kept closed during peak sunlight hours.
Benefits of Blackout Blinds in Hot Weather
While they’re often associated with sleep and privacy, blackout blinds offer several benefits during hot weather.
Cooling Benefits:
- Block sunlight before it heats up interior surfaces
- Maintain a consistent indoor temperature
- Reduce the need for air conditioning or fans
- Improve comfort during heatwaves or summer months

Comparison: Blackout Blinds vs Other Cooling Blinds
Are blackout blinds the best blinds for hot weather? Let’s compare them to other options:
Cooling Blinds Compared:
- Blackout blinds – Great at blocking light and reducing glare; moderate heat reduction
- Thermal blinds – Specifically designed with insulation in mind; better at both heat retention and reduction
- Solar shades – Reflect UV rays while allowing some visibility; highly effective at reducing heat
- Venetian blinds – Allow adjustable light control; less efficient at blocking heat unless tightly closed
Best Blackout Blinds for Hot Weather
To maximise the heat-reducing potential of blackout blinds, choose designs made with thermal or reflective backing.
Top Recommendations:
- Thermal blackout roller blinds – Compact, effective, and ideal for minimalist interiors
- Cassette blackout blinds – Include side channels for full blackout and better insulation
- Double roller blinds – Combine a blackout layer with a sunscreen layer for daytime and night-time use
Tips for Keeping Rooms Cool with Blackout Blinds
To get the most from your cooling blinds, use them strategically:
Practical Tips:
- Close blinds before the sun hits the window – prevents heat build-up
- Pair with light-coloured curtains – adds insulation and reflects heat
- Ventilate at night- open windows and blinds in the evening to let cooler air in
- Use window film or external awnings – for extra protection from solar gain
Fit your home with the perfect heat reducing blinds
Broadview Blinds is a leading specialist in residential and commercial blinds. Our team supplies and fits manual and automatic blinds across the south, so whether you’re looking to cover up south facing windows, or re-fit your house with stylish blinds that offer optimal heat reduction properties, pop into our showroom in Poole to explore your options.
From Venetian blinds to roller blinds, shutters to curtains, Broadview is your answer to keeping the heat out. If you have any questions, don’t hesitate to give our friendly team a call on 01202 679012.
