Do thermal curtains keep heat out in the summer? Experts reveal whether these window dressings are worth buying

As we find ourselves at the beginning of summer with the first (but certainly not the last) heatwave of the season behind us, we’re pondering how to best keep our homes - and by extension ourselves - cool and less bothered in the coming months. And while thermal curtains are traditionally associated with keeping the heat in during the winter months, we can’t help but wonder – do thermal curtains keep heat out too?

This specialised window treatment idea is specially designed with built-in layers and/or linings to prevent heat from escaping your home when it’s cold outside, which in turn helps to keep energy bills down - a benefit that’s particularly appreciated amid the energy and cost-of-living crises.

‘In 2023, we found that installing heavy curtains can have possible yearly savings of up to £344.50 – and that is even without factoring in thermal linings,’ reveals Leah Aspinall, head of design at Blinds 2go.

However, the shift of seasons and temperatures has led us to question the usefulness of thermal curtains during the warmer months and whether they are as effective in stopping extreme heat from the outside coming in as they are at keeping your house warm in winter. And that’s exactly what we’ve asked our experts to enlighten us about.

What are thermal curtains and do they keep heat out?

First of all, we should probably clarify what exactly thermal curtains are and how they work.

‘Thermal curtains are a great way to improve the thermal efficiency of a room,’ says Ana Zuravliova, trend specialist at Blinds Direct. ‘Made from multiple layers of material to improve thermal resistance, thermal curtains help to maintain a room’s warmth in a similar way to a winter coat. The same is true for special thermal linings which are added to the fabric during manufacture. By creating dead-air space between you and the cold, rooms retain their heat, which not only keeps the room a more pleasant temperature, but also reduces energy consumption and lowers bills.’

But given that Ana compares this curtain idea to a winter coat, which certainly doesn’t keep the heat away if you wear it in summer, does that mean thermal curtains are ineffective in the summer heat?

‘Thermal curtains can keep heat both in and out; their insulating layers trap heat at the window when it’s colder outside to keep the room they’re in warm, but they also work to keep the heat out by preventing solar heat from entering through its thick layers in the hot weather,’ Leah explains.

What rooms are thermal curtains recommended for in the summer?

As the experts are big fans of the benefits that thermal curtains provide all year round, confirming they are a worthwhile investment, perhaps the only question remaining is what type of rooms will benefit from them the most.

Ana believes they make for the perfect summer bedroom curtain idea, ‘For rooms where you relax, and especially sleep, we would absolutely recommend thermal curtains. Temperature - whether it's being too hot or too cold - is one of the leading causes of poor sleep quality in both adults and children.’

Leah continues, ‘Homes with large windows or patio doors are at particular risk for significant heat gain in the summer and loss in the winter. Thermal curtains will provide an effective barrier, improving the overall energy efficiency of the home. Single-glazed windows are another key source of heat loss. I’d recommend installing thermal curtains to any single-glazed windows to help to reduce draughts and improve insulation.’

Our top thermal curtain picks

Even though we’ve gone for neutral-coloured options because they go with almost any interior styles and colour scheme, all of these come in a variety of shades for you to choose from.

FAQs

Do thermal curtains make a room hotter?

Thermal curtains won’t make a room warmer on their own as they are entirely dependent on outside conditions. But they will assist in keeping a room warm if you heat it up, not allowing the warmth to escape through the windows.

‘Whether thermal curtains make a room warmer depends on the temperature outside,’ says Leah Aspinall, head of design at Blinds 2go. ‘If the weather is particularly hot outside then thermal curtains will help to prevent the heat from penetrating into the room and making it hotter. But when it’s cold outside, thermal curtains prevent the heat that is already inside from escaping through the fabric, helping to keep the space warm.’

She adds, ‘Thermal curtains help keep the room warmer for longer, making them an energy efficient choice and also reduces the amount you need to spend on heating.’

Do thermal curtains cause condensation?

Thermal curtains should not cause or make condensation in your home any worse. If anything, they should help with this issue.

‘While regular curtains can exacerbate the problem by trapping warm air against the windows, thermal curtains are specially designed to help reduce condensation on the inside of your windows,’ says Ana Zuravliova, trend specialist at Blinds Direct. ‘By creating a dead-air space between the window and the room, the warm air doesn’t get trapped against the glass and as a result, condensation is reduced.’

So it seems that thermal curtains get a big thumbs up!