As you can imagine, blackout curtains are most commonly used to create complete blackness in a living space, even during the day.
Given that these curtains are typically quite thick, people often wonder if these curtains insulate as well.
Furthermore, when so many blackout curtains are also advertised as thermal insulating, people commonly wonder if they truly do block heat and cold or if they are just labeled as “thermal” for advertising purposes.
However, blackout curtains specifically designed just to darken rooms do, in fact, block out heat and cold, providing SOME insulation. These curtains often just aren’t as effective for insulating as thermal curtains.
By understanding blackout curtains and their insulating qualities, you can make an informed decision on what types of curtains are best for you.
How blackout curtain can keep your room cool in the summer and warm in the winter
Whether it might be blackout curtains or your typical fully lined curtains, any curtains on the thicker side can provide some degree of insulation.
But how?
Simply put, curtains provide an extra barrier between the inside and outside of your house.
Even the best quality windows often allow for some air to leak in and out of your house. Curtains, however, can reduce this air leakage to some degree. Curtains make it more difficult for air from outside to seep into your living space and vice versa.
For instance, in the winter, when you want to keep the heated air from leaking out of your house, your closed curtains block off much of the warm air inside from reaching your windows where it can escape.
In the summer, when you want to keep your house feeling cool, closed curtain prevents much of the air-conditioned air inside from reaching your windows where it can leak out.
That being said, blackout curtains can certainly help better insulate your home… but likely no better than you typical fully line curtains. Curtains that are specifically just designed for blackout purposes are typically not made with any special thermal material that makes them better for insulation than any other pair of thick curtains.
Additionally, the degree to which your curtains insulates doesn’t only depend on the curtain material. A set of curtains insulating ability depends on how much space around your window your curtains can cover, and how airtight they are. In general, the less space between your curtains and window there is, the better they will be at insulating your windows.
Blackout curtains vs thermal curtains
Blackout curtains aren’t designed specifically for insulation purposes, however thermal curtains, also known as insulated curtains are different by design.
Blackout curtains are often made of two layers:
- Heavy decorative fabric on the side facing your room
- Thin liner stitched into the interior side of the curtain. This liner, of course, is responsible for blocking out the sunlight.
Thermal curtains are often built a bit more elaborately. These curtains often are comprised of three or more layers:
- Heavy decorative layer on the side facing your room. Sometimes two pieces of fabric for this layer are used for extra insulation.
- Acrylic foam that sits in between pieces of fabric. This high-density foam is responsible for giving these curtains their insulating qualities.
- Vapor layer, or the interior layer facing the window, responsible for preventing condensation from windows from seeping into the foam layer.
Sometimes heavy-duty thermal curtains even have a magnetic lining around the edges that connect with a complementary magnetic lining that you attach to the perimeter of your window. This way when you shut your curtains, the edges of your curtains will “stick” to the sides of your window to better prevent heat or cold from permeating through your window and into your room.
Which curtains are best for me?: Pros and cons of both…
There are a few advantages and disadvantages of curtains made solely for blackout purposes and curtains designed specifically for thermal insulation.
Blackout curtains are sometimes a bit lighter than thermal curtains. Because these curtains really only need to be made of tightly-woven fabric to completely darken your room, they often aren’t designed to be super heavy. This makes setting them up, taking them down and using them in general quite easy. In addition, you can wash blackout curtains quite easily as well which makes them easy to maintain.
On the other hand, thermal curtains are often a bit heavier given that they commonly have extra layers of foam and fabric for insulation. This can make the set up for these curtains a bit more tedious. You must make sure that your brackets for your curtains are plenty sturdy enough so that they can support the weight.
However, keep in mind that although blackout curtains do provide some insulation, the extra insulation from thermal curtains will lead to much greater energy savings. Thermal curtains that are specifically designed for the purpose of blocking airflow between your house and outside will surely be more cost-effective in the long run than curtains not designed for this purpose. The savings might be small day by day, but over the course of a year or two, the saving will really add up.
But wait… don’t thermal curtains darken rooms just like blackout curtains?
Flipping through any Amazon or any online décor store, you might see curtains advertised as thermal AND “100 percent blackout”.
Naturally, you might think that thermal curtains labeled as blackout, soundproof ect, are advertized this way simply for marketing purposes. Understandably so.
However, given the thickness of most thermal curtains and that they are often made to fully extend your entire window to block as much air leakage from your windows as possible, these curtains naturally block sunlight extremely well. Thermal curtains often truly do blackout windows given their design.
For this reason, thermal curtains may be the better choice over blackout curtains. It doesn’t make much sense to buy cheap blackout curtains that don’t insulate for a little less money than thermal curtains that also blackout your room.
Final thoughts
Ultimately, pretty much all curtains on the thick side insulate to some degree. Whether it be standard fully lined curtains, blackout curtains, or thermal curtains, all of these curtains can save money and energy. However, thermal curtains by design are undoubtedly better at doing so.
In turn, if you are stuck deciding between blackout and thermal curtains, if insulation is a priority, your choice should be obvious.
