Do Blackout Curtains Block Heat?

Do blackout curtains block heat or they only block the sunlight from entering your room? Is it even possible for a curtain to perform dual function? Can blackout curtains, in addition to blocking UV, cut down your energy bills? Let’s find out answers to these questions.

In this post, we’ll be covering the following topics in detail:

Read Also : Best Blackout Curtains for Day Sleepers

The effects of global warming predicted by scientists in the past are now starting to appear. Loss of sea ice, rise of sea-level, and intense heat waves are a few examples of it. These heat waves raise the temperature of homes, cause adversarial effects on mental health, and can trigger devastating wildfires.

Furthermore, the heat waves not only raise the temperature of your home, but it can also damage your furniture. So, to tackle the outside heat and its effects, one solution is to install a blackout curtain.

What Are The Advantages Of Using Blackout Curtains?

Most of the people are well aware of the fact that the blackout curtains can block the natural-light efficiently and it is one of the main reasons why they buy blackout curtains in the first place. Some might even believe that it blocks out 100% of the sunlight. However, it might be a good idea to read the manufacturer’s manual to know how much percentage of the sunlight it can block. Also, some brands claim to block 99% of the sunlight. Of course, it is still a very efficient and reliable percentage, but there’s more to blackout curtain than just blocking out the sunlight.

Below are some of the benefits of using blackout curtains

Helpful For Night Owls, Insomniacs And Night-Workers

Blackout curtains are a match made in heaven for insomniacs and for those who regularly work at night. Irregular sleeping habits can cause health problems for those who work night shifts. And they cannot find sleep during the day because of the sunlight. Therefore, blackout curtains can create an ambiance of night and can help them sleep better. Also, these curtains are helpful for children as they can help them fall asleep faster.

The Ambiance Of A Cinema

If you have a media room or home theater system in your house, and you want to create an ambiance of a cinema, then to create darkness, you need to have a blackout curtain to block any light any coming in. 

Urban Problem

Furthermore, blackout curtains can help out those living in a buzzy city as well. The flashing lights and neon can keep you up for hours without any sleep. Blackout curtains can cut all of that light and help you get to sleep. Also, blackout curtains have known to damp noise to some extent as well. 

Places Where The Sun Shines For A Day

There are some parts of the world where the sun shines for about 20-22 hours a day. If you’re living in that area, then it might be difficult to tuck yourself in the bed when the sun is shining like its 2 at noon whereas, in reality, it is 10 at night. Blackout curtains, in such a scenario, can help in blocking out the light and help you get that 6-hour healthy sleep.

Do Blackout Curtains Block Heat?

Well, the primary function of a blackout curtain is to block the light directly reaching you from the sun. But most of the homeowners want to know that if these curtains can block the heat as well. The answer is, fortunately, yes. Yes, blackout curtains can block heat in addition to light as well.

The blackout curtains can curtail the heat transfer from windows to your room by about 24%. As a result, your room would be warmer in winter and cooler in summer.

Furthermore, in addition to reducing energy loss, blackout curtains can save you some money by putting less load on your cooling and heating systems, and subsequently adding fewer digits to your energy bills. Without these curtains, your furnace and the air conditioner has to work doubly during winter and summer season to make the room temperature comfortable.

What Are The Types Available

There are a variety of blackout curtains available in the market, such as 

  • Thermal Insulated Curtains 
  • Roll-down Blackout shades 
  • Ring Top Curtains 
  • Pencil Pleat Curtains, and 
  • 3D Blackout Curtains. 

These products have a plain design and have a reasonable price.

Furthermore, they come in different sizes and lengths so that you can easily fit them into your windows. After pulling them down, you can block the sunlight and its heat without any hassle. Also, they are available in multiple colors as well, such as white, pink, brown, grey and pink, etc.

Additionally, blackout liners are also available, and they have the advantage of working in association with your current window treatments. In addition to blocking out sunlight and its warmth, they protect the existing curtains in your home as well.

If you want to experience the full-on benefits of blackout curtains, you should buy them directly. Blackout curtains, as mentioned before, are available in a variety of sizes and lengths, so it is wise to measure the dimensions of your window and buy the curtain accordingly. It is necessary to ensure that you get the right dimensions because if some part of the window is left uncovered, then you might not be able to experience the full effect of the blackout curtain. 

However, if you’re not up to the task of buying the curtains directly, then the option of sewing it yourself is always available, and surprisingly, sewing blackout curtains are not that hard. If you’re not into the look and matching your curtains with the decor of your house, then this is the most economical option as well.

Also, you can buy the decorative fiber just like a knit or woven fabric in a range of colors and prints. It doesn’t matter if the color of the decorative fiber is dark or light because the foam is what blocks the heat and sunlight from entering your house.

Things To Consider Before Buying Blackout Curtains

There are certain things which you can consider before buying blackout curtains. 

Firstly, take a closer look at the fabric and make sure it is made up of mid-weight or heavy-weight spongy material so that it can prevent both heat loss during winter and heat gain during summer efficiently.

Secondly, if your priority is to block the sunlight during summer, then it is advised to buy curtains with light-colored backing as it would reflect the light compared to dark-colored backing curtain.

Last but not least, carefully measure the dimensions of your window so that the curtains must cover every inch of the window, otherwise they would not work as they are intended to.

Blackout Curtain Tips

There are some tips to follow to maximize your energy and greenhouse gas emission savings:

The blackout curtains’ gather should be sufficiently above the rod to block the light from appearing at the top. Additionally, make sure that the curtain is as close to the window as possible, and use magnetic tape to stick the curtain to the sides of the windows so that the heat may not enter the room. 

The best practice in the summer is to close the curtains of the windows which receive direct sunlight. Otherwise, the sunlight will heat your home and will increase the cooling cost. During night time, you can close the curtains so that the cooling will not escape your room and it will lower your cooling cost as well.

On the other hand, during winters, you can open your curtains during the day so that the sunlight can warm your room. However, if the sunlight is not reaching directly to you, then it is advised to close the curtains. Furthermore, all of your curtains should be closed at night so that the warmth will not escape your room.


Before considering to buy a blackout curtain, it is worthwhile to know what a blackout curtain can and cannot do. Primarily, people use it to block out the light, but they can block heat, as well as, save you from high energy bills. 

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