Will Blackout Curtains Keep Heat Out?

When summer temperatures climb, many homeowners look for simple ways to keep their homes cooler without relying entirely on air conditioning. One of the most effective window treatments for reducing heat gain is a quality set of blackout curtains. While they're best known for blocking light, they can also help improve indoor comfort by limiting the amount of solar heat entering through your windows.

Will blackout curtains keep heat out?

If you've been wondering, will blackout curtains keep heat out? The answer is yes, especially when they're properly fitted and made with thermal linings.

How Blackout Curtains Reduce Heat

Windows are one of the largest sources of unwanted heat gain in a home. Solar radiation entering through windows can significantly increase indoor temperatures during warmer months, particularly on south- and west-facing elevations.

Blackout curtains help by creating an additional barrier between the window and the room. Dense fabrics, combined with insulated or thermal backings, reduce the amount of radiant heat that passes through the glass. Instead of allowing sunlight to warm furniture, flooring and interior air, the curtain reflects or absorbs much of that heat before it reaches the living space.

The result is a room that stays cooler throughout the day and places less demand on your cooling system.

Custom Curtains Perform Better

Not all blackout curtains offer the same level of performance. Ready-made curtains often leave gaps along the top and sides of the window, allowing sunlight and warm air to enter. Custom curtains are made to the exact dimensions of your windows, providing fuller coverage and a more effective barrier against both light and heat.

Proper fullness also contributes to performance. Well-designed drapery creates deeper folds that trap air between the curtain and the window, adding another layer of insulation.

For homes with large windows or expansive patio doors, professionally measured curtains can make a noticeable difference in comfort.

They're Helpful in Winter, Too

The benefits of blackout curtains aren't limited to summer. During colder months, thermal-lined curtains can help reduce heat loss through windows by slowing the transfer of warm indoor air toward the colder glass. 

While they won't replace quality windows or insulation, they can complement your home's building envelope and contribute to a more comfortable indoor environment throughout the year.

Combined with thoughtful fabric selection, blackout curtains become both a design feature and an energy-conscious investment.

Style Meets Performance

Today's luxury curtains offer far more than room-darkening benefits. Available in elegant linens, velvets, textured weaves and designer fabrics, blackout linings can be incorporated into virtually any decorating style without compromising appearance.

At Auburn & Ash, we create custom curtains that balance beauty with performance. Whether you're looking to block early morning sunlight, improve energy efficiency or create a more comfortable bedroom, we'll help you choose window treatments tailored to your home and your lifestyle.