Thermal blinds are insulating window blinds that trap a layer of air or use a lined, reflective fabric to slow down heat escaping through the glass. They keep rooms warmer in winter, cooler in summer and can help cut heating bills. Independent tests at the University of Salford found a blockout honeycomb blind in a framed, clip-in system cut heat loss through a window by 32%. At 1ClickBlinds every thermal blind is made to measure.
Windows are one of the main places a home loses heat. A thermal blind adds an insulating layer between the cold glass and your room, so your heating works less hard. The best thermal blinds sit close to the glass and seal the edges, which is why honeycomb and perfect fit designs perform so well.
Thermal blinds: the quick answer
- What they are: blinds made to insulate, using air pockets, linings or reflective backings.
- Best type: honeycomb (cellular) blinds, especially in a clip-in frame with side channels.
- Do they work? Yes. Tests found up to 32% less heat loss with a framed honeycomb blind and 13% with a standard roller blind.
- Summer benefit: they also block strong sun and help keep rooms cooler.
- Extra benefits: many thermal blinds are also blackout and help soften outside noise.
- Made to measure: a close fit is what makes a thermal blind work, so every blind is made to your size.
How much do blinds reduce heat loss?
Research commissioned by the British Blind and Shutter Association (BBSA) and carried out at the University of Salford's Energy House tested different blinds on an energy-efficient double-glazed window.
| Window covering tested | Reduction in heat loss through the window |
|---|
| Roller blind with zip side channels and low-e fabric | 33% |
| Blockout honeycomb blind in a framed bead-fit (clip-in) system | 32% |
| Internal plantation shutter | 28% |
| Roller blind with side channels | 22% |
| Standard roller blind | 13% |
Source: BBSA and University of Salford Energy House research (2023). The lesson is simple: the closer the blind sits to the glass and the better it seals the edges, the more heat it keeps in.
Types of thermal blinds
| Thermal blind type | How it insulates | Best for |
|---|
| Honeycomb (cellular) blinds | Honeycomb-shaped cells trap a layer of air, and side channels seal the edges | Bedrooms, cold rooms, tilt and turn windows |
| Thermal blackout perfect fit pleated blinds | Blackout pleated fabric in a frame that clips tight to the glass | uPVC windows, conservatories, French doors |
| Easy Stick honeycomb blinds | Honeycomb cells, fitted with adhesive and no drilling | Windows with no rubber seal or recess |
| Thermal blackout blinds | Dense or coated blackout fabric that adds a solid layer | Bedrooms and nurseries |
| PVC blackout vertical blinds | Solid PVC slats that overlap when closed | Wide windows and patio doors |
How do thermal blinds work?
- They trap air: still air is a good insulator. Honeycomb cells hold a layer of air between the glass and your room.
- They seal the edges: frames and side channels stop warm air escaping round the sides of the blind.
- They reflect heat: lined or foil-backed fabrics reflect heat back into the room in winter and reflect sun away in summer.
- They stop draughts: a close-fitting blind reduces the cold air that falls down from the glass.
Want the full detail? Read do thermal blinds really work?
Thermal blinds vs blackout blinds vs standard blinds
| Thermal blinds | Blackout blinds | Standard blinds |
|---|
| Main job | Keep heat in and sun heat out | Block light | Privacy and shade |
| Insulation | High | Medium (thicker fabric helps) | Low |
| Darkness | Often blackout too | High | Low to medium |
| Best rooms | Cold rooms, bedrooms, conservatories | Bedrooms, nurseries, TV rooms | Living rooms, kitchens |
Many blinds do both jobs. Read thermal blackout blinds explained.
Thermal blinds by room and window
- Bedrooms: thermal blackout or honeycomb blinds keep the room warm and dark for better sleep.
- Conservatories: lots of glass means big heat loss in winter and heat gain in summer. Perfect fit pleated and honeycomb blinds on each pane help most. See conservatory blinds.
- Tilt and turn windows: clip-in thermal blinds move with the window and stay sealed to the glass.
- Patio and French doors: a perfect fit blind on each glass panel, or thermal vertical blinds across a wide opening.
- Older or single-glazed windows: these lose the most heat, so a thermal blind makes the biggest difference.
- North-facing and cold rooms: keep the blind closed after dark to hold in the day's warmth.
How to get the most from thermal blinds
- Close them at dusk: lower your blinds as soon as it gets dark to trap the heat.
- Open them on sunny winter days: let free solar heat warm the room, then close them before sunset.
- Close them on hot summer days: block sun on south and west-facing windows to keep rooms cooler.
- Choose a close fit: blinds fitted to the glass or with side channels keep in the most heat.
- Do not cover radiators: keep blinds above or beside radiators so heat can reach the room.
How to measure for thermal blinds
- Perfect fit and honeycomb blinds: measure the visible glass, not the whole window, in three places and use the smallest number. Follow our perfect fit measuring guide.
- Recess blinds: measure the inside of the window recess at the top, middle and bottom and use the smallest width.
A close, accurate fit is what makes a thermal blind work, so measure carefully.
Frequently asked questions
What are thermal blinds?
Thermal blinds are blinds designed to insulate your windows. They use trapped air, lined fabrics or reflective backings to slow heat loss in winter and block heat in summer.
Do thermal blinds really work?
Yes. Research at the University of Salford found a framed honeycomb blind cut heat loss through a window by 32%, and even a standard roller blind cut it by 13%.
Are thermal blinds worth it?
Yes, especially for cold rooms, bedrooms, conservatories and older windows. They make rooms feel warmer, can help reduce heating bills and often give blackout and privacy too.
What are the best thermal blinds?
Honeycomb (cellular) blinds are the best thermal blinds, because their cells trap air. They work best in a clip-in frame with side channels that seal the edges.
Do thermal blinds keep the cold out?
Yes. They add a layer between the cold glass and your room and cut down the cold draught that falls from the window.
Do thermal blinds work in summer?
Yes. Closed thermal blinds block strong sun and reflect heat, so rooms stay cooler on hot days.
Are blackout blinds thermal?
Not always. Blackout blinds block light, but only some are made to insulate. Thicker blackout fabrics help a little, while honeycomb and lined thermal blackout blinds do both jobs well.
Do thermal blinds stop condensation?
No. Thermal blinds can make the glass behind them colder, so condensation can still form. Good ventilation and opening the blind in the morning help.
Can I get thermal blinds without drilling?
Yes. Our honeycomb and perfect fit pleated blinds clip into uPVC windows, and Easy Stick honeycomb blinds fit with adhesive. Browse all no drill blinds.
Are thermal blinds good for conservatories?
Yes. Conservatories lose and gain a lot of heat through the glass. Thermal blinds on each pane help keep them warmer in winter and cooler in summer.
Do thermal blinds reduce noise?
They can help. Layered honeycomb fabric and a close fit soften some outside noise, but they will not soundproof a room.
Can thermal roller blinds keep heat in?
Yes, but less than honeycomb blinds unless they have side channels. Read do thermal roller blinds keep the heat in?
Are thermal blinds made to measure?
Yes. At 1ClickBlinds every thermal blind is made to the size you give us, because a close fit is what keeps the heat in.
How much energy can thermal blinds save?
It depends on your windows, home and heating. Read how much energy thermal blinds can save in the UK.
Explore more: honeycomb blackout blinds and thermal roman blinds.
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