By Tony Carrick and Stacey L Nash | Updated Feb 3, 2022 10:01 AM

BobVila.com and its partners may earn a commission if you purchase a product through one of our links.

Even the highest-rated windows present an opportunity for air to infiltrate your home, causing your HVAC system to work harder to keep your house warm in the winter and cool in the summer. Thermal curtains are an extra layer of insulation you can use to make your home more energy efficient.

The best thermal curtains consist of multiple layers of fabric with thick padding that prevents air from circulating from your window into your home. In addition to this insulating effect, these window treatments have the added advantage of dampening sound and blocking light.

With so many brands and styles to choose from, selecting a set of thermal curtains that will add efficiency to your home’s heating and air conditioning system while meshing with its aesthetics can be a challenge. This guide will review the features you should consider in a set of thermal curtains and includes a list of some of the best products available. We tested each of the curtains on our list, noting their ability to insulate and block light. They were hung in bedrooms and tested during cold winter temperatures.

Although the fabric used to create thermal curtains is crucial to how well it insulates the windows in your home, you also need to consider other factors, including size, noise reduction, and aesthetics.

Thermal curtains are available as standard classic curtains as well as Roman shades, hobbled shades, balloon shades, and side-draw shades, to name a few. Thermal curtains consist of insulated padding sandwiched between material suspended by a curtain rod that prevents air from passing into the room from the window.

Side-drawn shades work best for large windows, French doors, and sliding-glass doors. Roman shades and hobbled shades open and close through this classic stacking style. Balloon shades function similarly but gather the fabric as they rise. Unlike conventional blinds, Roman and balloon shades feature thick padded material that works well for insulating.

Thermal curtains come in various sizes ranging in widths from 36 inches up to 52 inches and lengths from 54 inches to 108 inches. For the curtains to properly insulate, they should be large enough to cover the entire window casing.

Beyond that, the size you want depends on the look you’re trying to achieve. For a traditional look, mount the curtain rod so that the curtain hangs from 6 inches above the top of the window frame to about 3 inches below the bottom of the frame. The curtains should also extend beyond either side of the window by 3 inches. For modern style, mount the rod as close to the ceiling as possible and allow the curtains to extend to about 1 inch above the floor, or allow them to rest on the floor to create a puddled effect.

If you’re using blinds or shades, they must fit tightly inside the window casing to prevent air from leaking around the edges of the blinds.

Like standard curtains, insulated curtains come in a wide variety of fabrics, including cotton, polyester, silk, microfiber, and even velvet. Polyester and microfiber are the most effective fabrics for thermal curtains, as they resist moisture, which can build up in the air trapped between the curtain and the windowpane.

While insulated curtains may make you think of tacky window treatments found in cheap hotel rooms, they come in a wide variety of stylish colors and patterns. These curtains go beyond being functional, featuring attractive grommets and cuts that allow you to achieve traditional, modern, and classic looks.

The thick layers of material in an insulating curtain not only prevent heat loss in your home, but they also absorb sound waves. This works both ways, muting the sound of your neighbor’s barking dog or screaming children while also muffling your own loud music. Thermal curtains can reduce the noise in your home by as much as 10 decibels.

Thermal curtains use multiple layers of material to insulate. The middle layer, which is the insulating layer, consists of heat-resistant material such as foam, felt, thick cotton batting, or flannel. A thermal curtain should have at least two layers, although three is better. For maximum insulation in the summertime, they should also use blackout technology that eliminates up to 90 percent of light.

Whether you’re talking about the insulation in your home’s walls or thermal curtains, insulation is measured using what’s known as R-value. The higher the R-value, the better the insulation qualities of the material. R-value generally ranges from 0, which is open-air, to attic insulation, which has an R-value of as high as 60. Windows also have an R-value. Single-pane windows have an R-value of 1, while Energy Star–rated windows typically have an R-value of 3. When properly installed, an insulated curtain can increase a window’s R-value to as high as 6.

Some curtains are machine washable, making them easy to maintain. Many thermal curtains are even safe to dry in the dryer. Others require the trip to and expense of a dry cleaner. Be sure to follow the manufacturer’s instructions for cleaning to avoid damaging your curtains.

There are a variety of benefits to owning thermal curtains. With their multiple layers of fabric, these curtains provide an extra layer of insulation for your windows, saving you money on your utility bills.

The same triple-layer design that keeps cold air out and warm air in, or vice versa in the summertime, also does an excellent job of dampening outdoor noise, creating a more peaceful environment inside your home.

Thermal curtains also do a great job of filtering out light. Darker-color curtains will actually block all sunlight, allowing you to sleep in on those sunny Sunday mornings. This dense material also provides maximum privacy for bedrooms.

With so many different types of thermal curtains on the market, it can be difficult to make a decision. This list breaks down some of the best options in a variety of categories.

With its high insulating and light-blocking qualities, this thermal curtain from Best Home Fashion adds that extra layer of insulation to windows while contributing to the room’s aesthetics. It features triple-weave polyester construction that includes a layer of black yarn, keeping out up to 99 percent of light—the darker colors are most effective—and 100 percent of UV rays, helping to keep your home warm in the winter and cool in the summer.

Each panel features attractive antique bronze grommets that are 1.6 inches in diameter. These panels come in three sizes: 80 by 96 inches, 100 by 96 inches, and 100 by 108 inches. With 18 solid colors ranging from cardinal red to sky blue, there are plenty of options for matching your home’s decor. These curtains are machine washable, making them easy to maintain.

These curtains did an excellent job of insulating and blocking light. We tested the extra-wide curtain panel in burgundy. The dark, rich color kept nearly all light out, and the thick fabric draped well. The only downside to these curtains is that the back side of the curtain is the same color as the front. Those who like uniform curtain colors from the exterior of their home will need a second, neutral layer to face the street.

This set of thermal curtains from NICETOWN features insulating microfiber layers to simultaneously provide insulation while blocking out light. Each panel features a black yarn layer sandwiched between two microfiber layers, providing insulation against winter cold and summer heat while blocking up to 99 percent of sunlight as well as reducing noise.

These curtains feature 1.6-inch grommets, making them suitable for most standard curtain rods. A selection of 37 solid colors makes them ideal for a variety of styles. And, with sizes ranging from 29 by 45 inches to 55 by 96 inches, they’ll fit with both modern and classic looks. Their machine-washable fabric makes them easy to keep clean, though it can take some work to get wrinkles out.

During testing, we found the triple-layer design effective at hiding the inner black thread layer. However, we also found that the manufacturer’s claim of 99 percent light blocking was a bit of an exaggeration. While they did a good job of blocking out light and heat, we’d put the percentage closer to 75 to 80 rather than 99 percent. They also dampened some noise.

Window treatments don’t have to be expensive, as these thermal curtains from Deconovo prove. These energy-saving insulated curtains feature three layers of fabric for maximum blackout and insulation quality, allowing you to cut those energy bills without having to invest a lot of money up front.

These curtains include standard 1.6-inch grommets and are available in 11 size options. With 29 colors to choose from, you have plenty of options for matching your home decor. Cleaning the Deconovo curtains is easy: Just throw them in the washing machine on a cold, gentle cycle.

The Deconovo curtains look similar to the other curtains tested, even those that cost a lot more. They block out 75 to 80 percent of light and a similar amount of heat. The fabric doesn’t have quite the heft of some of the other curtains on the list, but they’re a great option for those on a budget. Keep in mind that the price is for a single curtain only—double the price to purchase a pair.

Add a bit of elegance to your living room or bedroom with this set of thermal curtains from August Grove. They feature a triple layer of fabric that provides excellent insulation while blocking out noise and 100 percent of light—and they live up to the claims of 100 percent. These curtains graced a main bedroom that had never been darker than when these curtains were up. The only way we could tell the sun rose was the light that peeked out the top of the window near the curtain rod.

A decorative outer sheer tulle curtain with floral and heart accents adds a romantic feel to this energy-efficient set. These curtains come in 11 pastel hues ranging from vapor (an off-white) to coral.

The three length options—63 inches, 84 inches, and 96 inches—allow you to achieve the right look for your room. All panels are 52 inches wide, and each panel attaches to the rod via eight stainless steel grommets. Two panels are included with this machine-washable set. The only issue we had with these curtains was the wrinkles in the tulle. They’re difficult to get out, and you can’t iron tulle without melting it.

With its diverse and rich collection of paisley patterns, the HLC.ME curtains add flair and visual interest. HLC.ME’s curtains use triple-weave polyester fabric to insulate the window, saving up to 30 percent on energy costs.

The HLC.ME curtains are machine washable and dryer-friendly on a low setting. The panels are all 50 inches wide and come in lengths ranging from 54 inches to 96 inches, allowing you to achieve looks ranging from tailored to elegant. Each set comes with two panels.

These curtains filter out about 60 percent of light and a similar amount of sound. In artificial light, the muted colors almost look faded. When light shines through these curtains, the silver light-blocking panel gives the paisley pattern a silvery cast. They’re a great option if you love the pattern, but they’re not the most effective at controlling temperature or light.

These thermal curtains add a sophisticated look to your living space while lowering your energy bill. They feature a unique striped, textured pattern in earth tones, including fig, navy, and dune. The fabric is designed to reduce noise and energy loss. This set also functions as blackout curtains, filtering out 90 to 100 percent of light.

This set is also easy to maintain and will hold up to machine washings. These curtains are designed to hang to the floor with length options of 84 inches and 96 inches. Panels are 50 inches wide. These curtains, which are sold as individual panels, hang from a standard 1.5-inch curtain rod via grommets.

These curtains did a great job of blocking light during testing. Their textured pattern offers a different look and feel than the usual smooth, solid-colored polyester thermal curtains. A unique feature was a white blackout panel on the back side of the curtain. For those who like a uniform look to their windows from their home’s exterior, these curtains let you achieve that with the neutral white backing.

With 22 colors to choose from, these thermal curtains from BGment have style options to suit most rooms. They feature a triple-weave design of microfiber and black yarn to insulate in both the summer and winter while remaining soft to the touch. We found that those three layers also muffle outside noises while blocking between 80 and 95 percent of light, allowing some sleeping in on the weekends.

Each panel includes six or eight 1.6-inch silver grommets (depending on the width), making them compatible with most standard rods. These curtains are easy to maintain, too. Simply throw them in the washing machine on the gentle cycle with cold water and tumble dry on low. BGment thermal curtains come in a variety of sizes ranging from 38 inches to 52 inches wide and between 45 inches and 95 inches long. Each set includes two curtain panels.

The wide color selection includes bold, deep colors that hold up to sunlight. However, they don’t have a neutral backing. The curtains will be the same color from the outside of the house as they are on the inside.

Barking dogs, road construction, and loud birds all seek to rob you of precious sleep. With their ability to block out 60 percent of sound, these polyester-blend thermal curtains from Utopia will restore peace in your home or at least help to reduce outdoor noise to a tolerable level. They also block out 99 percent of light, so you don’t have to worry about early morning sunrays that may be disturbing you.

This set of curtains comes in eight colors, including burgundy, navy, gray, and olive. Width options include 52 inches, with lengths of either 63 inches or 84 inches. Each panel features eight 1.6-inch grommets for easy hanging. These curtains are machine washable, making them easy to maintain as well.

These curtains are like hanging a blanket in front of the windows. They dampened sound well and blocked out approximately 90 percent of light, too. They’re limited in their size and color options, but if there’s a color that will work for you, these are a great curtain for quieting a room.

With a high-density layer of silk fabric at their core and microfiber polyester on the outside, H.VERSAILTEX’s thermal insulated curtains do an excellent job of keeping out the cold on frigid winter days. These curtains are triple woven to keep cold air at bay during the winter while holding warm air in, helping to keep your home toasty and your energy bill down. Attractive grommets and a sleek modern design add form to function.

These curtains come in 20 solid colors. In addition to their insulation properties, these curtains also effectively block out up to 95 percent of sunlight and help to reduce outside noise. They’re machine washable and dryer safe. With length options ranging from 63 inches to 108 inches, they’ll suit a variety of styles. The panels come in two widths, 42 inches and 52 inches.

We tested a set of deep red curtains that did an excellent job of insulating a bedroom, even in subfreezing temperatures. The fabric is on the stiff side, but they drape well, so it’s not really noticeable when they’re closed.

A summertime alfresco dinner stays cool and comfortable with thermal-insulated outdoor curtains. These multilayered backyard curtains from NICETOWN will provide cooling shade while also giving you privacy from the neighbors. They feature a layer of high-density black yarn sandwiched between two layers of polyester, protecting you from the sun’s damaging rays while also blocking wind.

Outdoor curtains wouldn’t be much good if they couldn’t endure the elements. These curtains are waterproof and include rustproof grommets. And when they get dirty, you can throw them in the washing machine to freshen them up. With 12 color options and a wide variety of sizes (in both width and length), these curtains will suit various patio sizes and styles.

We tested the 108-inch-length NICETOWN curtains. The length alone adds heft, but the fabric also makes these a heavier curtain panel, which is exactly what you want outdoors. They do an excellent job of controlling light and resist water damage, as long as you don’t leave them outside during a downpour. They’re sold as single panels, so measure your space carefully.

The Best Home Fashion Thermal Blackout Curtain provides quality materials, light and sound blocking, and a reasonable price. These curtains also come in a wide range of colors to fit with different interior designs. For those on a tight budget, the Deconovo Thermal Insulated Blackout Curtain also comes in many color options but will save a few dollars. Just remember that the curtains come in a single panel per package.

We tested all the curtains on our list and evaluated each of them by an established set of guidelines. All were installed in bedrooms. Their light-blocking abilities, thermal control, and quality were evaluated over several days of use.

Light-blocking abilities were tested by turning out the interior lights during the daytime to test the amount of light visible through the curtains. Thermal control was tested several times throughout the day by comparing the room temperature with the curtains open versus when they were closed.

We also took into account the fabric quality, thickness, and drape. These three factors also influence how well the curtains wash and wear over time.

If you’re wondering about what makes thermal curtains work or how to hang them so they are effective, read below for answers to these questions and more.

Although thermal curtains will actually function as blackout curtains due to the multiple layers of fabric they use to insulate the window, there are differences between these two curtain types. Whereas both feature multiple layers of fabric, thermal curtains feature a thick backing for insulation and may include a synthetic lining that resists moisture.

Thermal curtains use a triple or double layer of fabric with a layer of thick batting. The material is made of either polyester or microfiber to resist moisture, while the batting serves as a barrier that prevents air from entering the home.

While thermal curtains may not entirely keep cold out, they do raise the insulation level of windows, trapping cold air between the window and the curtain, preventing it from entering the room.

To hang thermal curtains so they are effective, it’s important to use the right size. Make sure the curtains extend beyond the window casing on all sides to provide enough coverage to block the air that passes through the window from entering the room. It’s crucial to make sure the curtains hang close enough to the wall so that there is no gap between the curtains that would allow air to pass between the two. This may require you to mount the curtain rod closer to the wall.

Most thermal curtains are machine washable, using cold water and a gentle cycle. Some can even handle a trip through the dryer. Just make sure to read the manufacturer’s instructions regarding care before attempting to machine wash your curtains.

Disclosure: BobVila.com participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for publishers to earn fees by linking to Amazon.com and affiliated sites.

Copyright © 2022 Acton Media Inc. All rights reserved.