How To Use Thermal Blinds To Keep The Heat Out This Summer
By Ana Zuravliova
With a little bit of luck, the temperature in the UK will continue to rise over the next weeks and months until – hopefully – the summer will be warm, sunny and give us all a post winter boost of happiness. While many are looking forward to the heat, living amongst it 24 hours per day, every day, can be a bit much. So should you consider air conditioning? Before you make any expensive choices, read on…
Table of contents
Use thermal blinds to keep the heat out
How do thermal blinds work in summer?
What are the best blinds to keep the heat out?
Using air conditioning in the UK
Air conditioning has long been common in cars, and it’s increasingly being installed in UK homes following trends from the USA. While it helps to keep a space cool, there are some drawbacks: it’s expensive and many rely on hydrofluorocarbons (HFCs) and chlorofluorocarbons (CFCs), it’s not great for the environment.
The cost of running air conditioning units can start to rack up, especially during today’s cost of living crisis with inflation and energy prices soaring. With units often costing over £1000, and costs exceeding £100 per month, air conditioning is something that is simply out of the reach of many.
So while air conditioning can provide immediate relief from high temperatures, it comes with significant financial and environmental costs, particularly when used frequently during warmer months. As energy prices continue to rise and sustainability becomes more important in home design, relying on active cooling systems is not always the most practical long-term solution.
Instead, a more efficient approach is to reduce heat before it enters the home in the first place. This is where the design and treatment of your windows becomes critical — as they are one of the main entry points for solar heat gain.
Why windows are the main source of summer heat gain
A large proportion of unwanted heat in homes enters through glazing. Sunlight passes through glass and is absorbed by interior surfaces, causing indoor temperatures to rise — a process known as solar gain.
Once heat enters a room, it is harder and more energy-intensive to remove. This is why prevention at the window level is far more effective than cooling the air afterwards.
Blinds act as a physical barrier that reduces the amount of solar energy entering your home in the first place.
How blinds help reduce heat in a room
Blinds manage heat in several key ways:
- Blocking direct sunlight before it enters the room
- Reflecting solar radiation back through the glass
- Creating insulating air pockets near the window
- Reducing surface heating on floors, walls, and furniture
Different blind designs achieve this in different ways, depending on material, structure, and fit.
Use thermal blinds to keep the heat out
Thermal blinds offer several benefits in hot weather. They enhance privacy and reduce glare, lower indoor temperatures to keep rooms comfortable, and reduce reliance on air conditioning, which saves energy and makes your home more environmentally friendly. By helping maintain a cooler indoor climate naturally, thermal blinds can also cut energy bills and reduce overall heating and cooling costs.
What are thermal blinds?
Thermal blinds are special window coverings designed with insulating materials that help regulate indoor temperature. There are three main types of thermal blinds. The first are blinds made using specialist thermal fabrics (including roller blinds), the second using innovative construction techniques to form cells that better insulate a space. These include special honeycomb blinds. The third type are Roman blinds which can be upgraded with a free thermal blackout lining. This lining makes the blind thermally efficient while also adding blackout functionality to a window.
How do thermal blinds work in summer?
Thermal-lined blinds aren’t just for winter, they also help keep your home cool during warmer months. By creating an insulating barrier between the window and the room, they prevent hot air from entering, reducing indoor temperatures and keeping spaces more comfortable.
This same technology that traps heat in winter works in reverse during summer, making rooms cooler naturally. Installing thermal blinds on bedroom windows can also improve sleep quality by maintaining a more comfortable temperature at night.
What are the best blinds to keep the heat out?
Combine a thermal lining with a Roman blind or curtain to block heat while keeping your windows stylish. Elegance doesn’t have to be sacrificed for comfort. Many of our Roman blinds and curtains offer a free thermal lining upgrade.
Honeycomb blinds, also known as cellular shades, are designed to trap air within their unique cells, creating an insulating barrier that keeps heat inside during winter and blocks unwanted heat in summer. This air cushion helps maintain a comfortable indoor temperature, reducing the need for heating or cooling and saving both energy and money. They’re available in a variety of colours and patterns, blending functionality with style while helping reduce energy use.
Day and Night blinds
Day and Night blinds offer a modern, stylish alternative to vertical or roller blinds, providing excellent privacy, light control, and a slim-line silhouette, perfect for summer.
Made from alternating fabric strips with varying transparency, these blinds create a chic striped effect while allowing you to adjust light and privacy with a simple chain. Fully raise the blind for maximum sunlight and views, partially lower for filtered light, or close completely for full blackout.
Crafted from premium fabrics and fittings, our Day and Night blinds combine quality with style. Explore our favourites below, or check out our Day and Night Blinds Buyers Guide for more details.
Blackout roller blinds
As you would expect from a blackout blind, these high quality rollers are extremely effective at blocking out all sunlight. The blackout fabric will also help to prevent sun damage to textiles in your home, such as leather sofas.
As well as controlling the light, blackout blinds are thermally efficient, helping to maintain a more comfortable temperature when it’s very hot. You will also benefit from noise reduction, which is particularly useful on summer evenings when you live in a busy area. And if views from the outside are a concern, rest assured that your blackout roller blind will fully obscure views into your home, offering a better level of privacy and protection than sheerer fabrics. Our blackout roller blinds are handcrafted with the highest quality fabrics and components, ensuring a seamless fit and optimum functionality.
Do blinds really make a difference in hot weather?
Yes — but their effectiveness depends on how and when they are used.
To maximise performance:
- Keep blinds closed during peak sun hours (10 AM – 4 PM)
- Use in conjunction with fans or natural ventilation to keep the air moving around the room
- Choose light-coloured blinds to reflect more heat
- Layer the window with thermal blinds and curtains with a thermal blackout lining for maximum thermal functionality
- Consider electric or smart blinds, which can be scheduled to automatically open and close at set times, ensuring optimal heat control even when you are not at home
Thermal blinds are more than just a winter solution. When used right, they are a highly effective and visually pleasing way to beat the heat and reduce energy use. Adding them to your windows can enhance comfort and create a relaxing indoor environment.
Extra ways to keep your home cool this summer
Beyond using thermal blinds, there are a few additional strategies that can help your home stay comfortable during hot summer days.
1. Close your blinds
Blinds are a great way to create a barrier between where you relax and the sun’s heat without having to keep your windows closed. By blocking the sun’s light from your space, you won’t only keep cool during the heatwave, you’ll also be able to enjoy the style of your space to its greatest extent! Whether you select a Roman blind or a roller blind, a well-made window covering will help block out the heat this summer.
Which way to close blinds to keep heat out?
If you use Venetian blinds, to keep the heat out, tilt the slats upwards towards the ceiling. This reflects sunlight away from the room while still allowing some natural light in. Conversely, tilting the slats downwards directs sunlight into the room can increase indoor temperatures.
2. The value of voiles
Voiles are an amazing addition to any space for the summer. Their semi-transparent fabric filters sunshine and fresh air into your home, while offering subtle privacy and even keeping small insects at bay.They can be used in any room, on any sized window, providing a good level of privacy without taking sunlight away from your space. When it’s especially hot outside, voiles provide a light shade, helping to diffuse the sun’s rays. They will also reduce glare, which is useful if you’re working at a computer, using a device or reading.
What’s more, voiles often look their best when part of a layered window or patio door. For example, you could fit stylish Perfect Fit® Roller blinds directly to your window or door, and then have voiles set outside of the recess to enjoy the best of both worlds throughout the year. Learn more about voiles in our Know The Difference: Voile Or Net Curtains? Blog post.
3. Find the right lining
Linings for curtains and Roman blinds include our thermal blackout option, but many think thermal linings are only for keeping you warm in the winter – they do even more than that!
In the same way they stop hot air escaping during the colder months, thermal linings block the hot air from the outside keeping you cooler during warmer days. Moreover, few window furnishings are as stylish as curtains or Roman blinds so why not feel cool in a cool looking space this summer?
4. Installation matters
Installation plays a crucial role in how effectively blinds reduce heat, and it is often underestimated. Even high-performance blinds can underperform if they are not fitted correctly, as heat and sunlight can still enter through small gaps around the edges of windows, through blinds that are too narrow to provide full coverage, or when the blind is positioned too far from the glass. For the best results, blinds should fully cover the window recess wherever possible, with side gaps kept to an absolute minimum to prevent sunlight from leaking in. Fitted systems such as Perfect Fit blinds can also help improve performance by creating a closer seal against the window frame.
In many cases, the quality of the installation has just as much impact on thermal efficiency as the blind material itself.
If you’re also looking at how other window furnishings can support heat control, you may find our guide to summer curtains useful, where we explore more ways to reduce heat and improve comfort using different fabrics and layering techniques.
Fingers crossed, we’ll enjoy an excellent summer full of lovely long days, carefree weekends and the formation of many wonderful memories. With just a few steps and a small investment, you can enjoy a cooling shelter from the sun to help you recharge before returning to the fun, and if you’re hoping to open up your patio doors and spend more time in the garden, you may enjoy reading some of our ideas for garden and patio doors.
Shop some of the best blinds for keeping the heat out:
Other posts you may be interested in:
Curtains with Thermal Lining
Discover how thermal lined curtains work, what they’re made from, and why they’re one of the easiest ways to keep heat in during winter and out during summer—without the cost or disruption of replacing your windows.
The Benefits of Smart Blinds
Learn how smart blinds integrate seamlessly with your connected home, offering hands-free control, improved security, and energy efficiency—without compromising on style.
Creative Ways to use Venetian Blinds
Venetian blinds are a stylish, versatile way to elevate any room. From classic wooden tones to vibrant coloured aluminium, their adjustable slats allow precise light control, while layering with curtains adds depth and sophistication.
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