Light-coloured blinds, particularly white are the best choice for keeping your home cool in summer. Dark coloured blinds, especially black blinds, can have the opposite effect. They'll do their job in terms of privacy and light control, but the dark colour will attract the sun and could potentially add to overheating.
Overall, white blinds can reasonably be considered to be better in terms of their ability to support an ambient temperature to some degree in both hot or cold weather; they're definitely better than black blinds in this respect if you look at the year-round picture.
If you want to prevent sunlight from entering your home then blackout shades and blinds are your best bet. These are shades that are made from a blackout fabric that prevents light from entering through. They are also great privacy blinds as one can't see through them from outside.
Dimout Blinds
Dimout roller blinds are a thinner type of material that will help to filter out the sunlight, whilst still allowing enough in that you can see what you're doing. These blinds are great for living rooms, kitchens, bathrooms etc.
Cellular blinds are some of the best blinds to keep light out. They're a popular option for bedrooms and living room spaces because they're also a very effective insulator, capable of reducing heat transfer by up to 80% and dramatically reducing your energy bill.
Light-coloured blinds, particularly white are the best choice for keeping your home cool in summer. Dark coloured blinds, especially black blinds, can have the opposite effect. They'll do their job in terms of privacy and light control, but the dark colour will attract the sun and could potentially add to overheating.
Faux-wood blinds and thick Roman blinds are good too; followed by real wooden blinds which are also great at insulating and keeping heat out in summer. Roller blinds (regular ones, as opposed to supersonic thermally insulating ones) come next, along with Venetian blinds.
Roller Blinds are a great choice for helping keep rooms cooler. The best fabric for this is a Blackout fabric, as this stops light from penetrating and thus helps keep heat out.
Using Tin Foil Or Cardboard
Tinfoil, or aluminium foil, is a common and inexpensive way to blackout your window.
Use window shades
One of the most cost-effective materials that block UV rays is window shades. Whether you prefer the look of woven wood shades, cellular shades, or Roman shades, look for an option that offers high UV protection. Some solar shades, for example, can block 99 percent of UV rays while letting in light.
Cheap Room Darkening Hacks
Covering windows with dark blankets or sheets is an easy and fast way to block out light. You could also try hanging up blackout curtains in front of your existing curtains. This will give you the darkening effect of blackout curtains while still letting in some light.
Colour. The colour of your blackout blinds can also impact their ability to keep heat out. Lighter colours tend to reflect more sunlight, which can help reduce solar heat gain. In contrast, darker colours can absorb more heat, potentially making your room warmer.
The short answer is yes – blackout blinds block sunlight, making them one of the best ways to keep a room cool. Keep your blinds closed all day and you'll find there's a noticeable difference in room temperature – and the more sunlight your blinds block out, the cooler the room will be.
Honeycomb shades are one of the best window coverings to keep heat out. The honeycomb design helps to insulate the window, and the cellular shade structure traps air to further reduce heat transfer.
Opt for blackout curtains: Invest in quality blackout curtains that are specifically designed to block sunlight effectively. Use curtain rods with return: Curtain rods with a return, also known as wrap-around rods, can help cover any gaps at the sides of the window, preventing light from seeping through.
Sunshine streams in through the window, and the gap in between the window and blinds captures the heat, producing a greenhouse effect. In the winter, this is a desirable effect, and in the summer, when you want it to be cooler in your home, all you have to do is raise the blinds to leave the window uncovered.
Roller Blinds for Keeping Heat Out
Roller blinds are effective for keeping heat out as they act as a barrier between the sunlight and the room. With roller blinds you can open your door/window whilst your blind is lowered.
A lighter-colored shade — like white or cream — will reflect more sunlight, but the view out will be less visible. A darker-colored shade, like black, will absorb more light, but the view out will be clearer.
White or light coloured curtains and blinds are better at reflecting heat and light away from your home. If you have thick, dark curtains, closing them will only trap heat in the room.
Thermal lining fabric has a thin, rubberised backing to it and is therefore effective at reducing heat loss. Blackout lining has an additional acrylic layer to prevent light passing through the fabric.
Down (Rounded Side Facing In)
In terms of practicality, it also allows more sunlight to stream in, as blinds turned in the down position have larger gaps. For this same reason, they're unable to provide as much privacy and room darkening as blinds turned up.
If you can't invest in curtains, consider blinds or window films that darken the space. Be sure your curtains are closed each night, and keep them shut tight using clips. Invest in a good sleep mask. While you might find some cute or attractive masks, look instead for comfort and function.