If you’ve ever wondered, “Do blackout curtains keep heat out?”, the short answer is: yes, they can help reduce heat from sunlight and improve indoor comfort—especially when they are properly installed and made with the right fabric or lining.
Blackout curtains are often chosen for their ability to block light, but their benefits go beyond darkness. They can help reduce heat from sunlight, improve privacy, and support a more energy-efficient home. For bedrooms, living rooms, nurseries, media rooms, and sunny windows, choosing the right custom blackout curtains can create a more comfortable indoor environment throughout the day. In the bedroom especially, a good pair of blackout curtains can help create the dark, quiet, and restful atmosphere needed for better sleep.
How Do Blackout Curtains Help Keep Heat Out?
Blackout curtains work by creating a barrier between the window and the room. Since windows are one of the main areas where sunlight and heat enter the home, covering them with thick or lined window curtains can help reduce heat gain.
High-quality blackout drapes can help:
- Block direct sunlight
- Reduce solar heat gain
- Keep rooms cooler during warm months
- Protect furniture and flooring from UV exposure
- Improve privacy and light control
- Support better sleep in bedrooms
This makes blackout curtains especially useful for bedroom curtains, living room curtains, nursery curtains, and rooms with large windows or strong afternoon sun.
Blackout Curtains vs. Thermal Curtains: What’s the Difference?
Many people compare blackout curtains and thermal curtains because both can improve indoor comfort. However, they are designed with different primary functions in mind.
Blackout Curtains
Blackout curtains are mainly designed to block light. They are usually made with dense fabrics, blackout lining, or coated backing to help reduce outside light from entering the room.
They are a great choice for:
- Bedrooms
- Nurseries
- Media rooms
- Rest areas for shift workers
- Rooms that need better privacy
In addition to light blocking, high-quality blackout curtains can also help reduce heat from sunlight and keep the room feeling more comfortable.
Thermal Curtains
Thermal curtains are mainly designed to help insulate against heat and cold. They often feature a thicker lining or specialized insulating layer to reduce temperature transfer between indoors and outdoors.
They are ideal for:
- Hot climates
- Cold winters
- Spaces that need stronger heat or cold insulation
- Energy-efficient window treatments
If your space requires more targeted temperature control, thermal curtains may be the more specialized choice.
How to Choose
If your main goal is to create a specific insulated space or you need stronger temperature control, thermal curtains may be the better option.
However, for everyday home use, if you want curtains that add style while also blocking light, improving privacy, and helping with heat control, blackout curtains with thermal lining or custom lined curtains are often the better choice.
These curtains offer a balance of beauty and function, helping create a quieter, more comfortable living environment while making bedrooms, living rooms, or media rooms feel more polished and complete.
Can Blackout Curtains Help in Winter Too?
Yes. While many homeowners use blackout curtains in summer, they can also help during colder months.
Thicker custom curtains and lined drapes can help reduce drafts and slow heat loss through windows. This makes the room feel warmer and more comfortable, especially in bedrooms and living rooms.
If you want year-round comfort, consider:
- Blackout curtains
- Thermal curtains
- Room darkening curtains
- Velvet curtains
- Lined linen curtains
- Custom drapes with blackout lining
Which Fabrics Work Best for Heat Control?
The fabric and lining matter just as much as the curtain style. Some materials naturally provide more coverage and insulation than others.
Velvet Curtains
Velvet curtains are thick, plush, and naturally insulating. They are a strong choice for room darkening curtains, blackout drapes, and cozy bedroom styling.
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Linen Curtains with Blackout Lining
Linen curtains offer natural texture and an elegant look. When paired with blackout or thermal lining, they become a beautiful and practical option for custom window treatments.
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Polyester Blackout Curtains
Polyester blackout curtains are common, durable, and effective for blocking light. They are often used for bedroom blackout curtains and everyday light control.
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Layered Curtains
Layering sheer curtains with blackout drapes gives you flexibility: soft natural light during the day and full coverage when you need privacy or heat control.
How to Hang Blackout Curtains for Better Heat Control
Even the best blackout curtains will not perform well if they are hung incorrectly. Small gaps around the window can let in light and heat.
For better results:
- Hang curtains higher than the window frame
- Extend the curtain rod 6–12 inches beyond each side
- Choose floor-length curtains
- Use wider curtain panels for full coverage
- Consider a wraparound curtain rod
- Choose custom sizing for large or unusual windows
For custom blackout curtains, accurate measuring is especially important. A wider and taller installation helps reduce light gaps and improves insulation.
Blackout Curtains vs Room Darkening Curtains
It’s also helpful to understand the difference between blackout curtains and room darkening curtains.
| Curtain Type | Light Control | Heat Control |
|---|---|---|
| Light Filtering Curtains | Softly diffuses light | Low to moderate |
| Room Darkening Curtains | Blocks more light | Moderate |
| Blackout Curtains | Blocks most light | Moderate to high |
If your goal is better sleep and strong light blocking, choose blackout curtains.
If your goal is heat control, choose thermal blackout curtains or blackout curtains with an insulating lining.
Do Blackout Curtains Save Energy?
Blackout curtains can support energy efficiency by helping reduce heat gain in summer and heat loss in winter. While they are not a replacement for proper insulation or energy-efficient windows, they can be a simple and stylish way to make your home more comfortable.
They may help reduce how often you use:
- Air conditioning
- Fans
- Heating systems
For the best result, choose custom curtains that fit your window closely and provide full coverage.
Final Thoughts: Do Blackout Curtains Keep Heat Out?
Yes, blackout curtains can help with heat insulation, especially styles made with thick fabrics, blackout lining, or thermal backing. They can effectively block direct sunlight and reduce heat from entering through the windows, helping the room stay more comfortable while adding a more complete and polished look to your space.
For better light blocking and heat control, it is recommended to hang curtains higher and wider, so they fully cover the window area and reduce light gaps and heat transfer at the top, sides, and bottom.
Custom blackout curtains are often the better choice. The right size allows the curtains to fit your windows more closely and helps reduce light leakage and heat gain caused by panels that are too short, too narrow, or not wide enough. If the curtain size is not accurate, the overall performance may still be affected, even if the fabric itself has blackout and insulating properties.
Therefore, if you want the best balance between style and function, custom blackout curtains are highly recommended. They can be tailored to your window size, room needs, and daily lifestyle, offering better light blocking, heat insulation, and everyday comfort for your home.
IXA Curtains, we create custom curtains that bring warmth, texture, and refined style to beautifully lived-in🔗 Shop the Collection at ixacurtains.com
FAQ
Do blackout curtains really block heat?
Yes. Blackout curtains can help block sunlight and reduce heat entering through windows, especially when closed during the hottest part of the day.
Are blackout curtains the same as thermal curtains?
No. Blackout curtains mainly block light, while thermal curtains focus on insulation. Some curtains combine both features with blackout and thermal lining.
What curtains are best for keeping heat out?
Thermal blackout curtains, lined curtains, velvet curtains, and custom blackout drapes are strong options for heat control.
Should blackout curtains be hung wider than the window?
Yes. Hanging blackout curtains wider and higher than the window helps reduce gaps where light and heat can enter.
Can blackout curtains help lower energy costs?
They may help improve energy efficiency by reducing heat gain in summer and heat loss in winter, especially when properly installed.
