{"id":9906,"date":"2026-11-06T02:01:43","date_gmt":"2026-11-05T21:01:43","guid":{"rendered":"https:\/\/loomandfiber.com\/blog\/?p=9906"},"modified":"2026-11-06T02:03:56","modified_gmt":"2026-11-05T21:03:56","slug":"do-blackout-curtains-block-heat","status":"publish","type":"post","link":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/","title":{"rendered":"Do Blackout Curtains Block Heat? A Guide to What Works and What Doesn\u2019t"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Do Blackout Curtains Block Heat? <\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Yes, but to some extent. Blackout curtains prevent sunlight from reaching surfaces within your room, which reduces the amount of heat those surfaces absorb. Medium-coloured drapes with a white plastic backing can reduce heat gains by up to 33%, according to the U.S. Department of Energy. Whether or not you\u2019ll get this level of reduction will depend on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Lining <\/strong>\u2013 white or light backing will be more effective.<\/li>\n\n\n\n<li><strong>Fit<\/strong> \u2013 any side\/top\/bottom gaps will let heat through.<\/li>\n\n\n\n<li><strong>Timing<\/strong> \u2013 if you close them before the sun hits the glass your room will be cooler. If you\u2019ve left them open until your room is hot then they won\u2019t remove the heat already stored in the room.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Blackout refers to how much light the curtains can block, not heat. Thin <strong><a href=\"https:\/\/loomandfiber.com\/blog\/what-is-a-curtain-panel\/?utm_source=chatgpt.com\">blackout panels<\/a><\/strong> can make your room dark but still hot. Blackout curtains will give a cheap option with no installation if you already have a suitable rod or track but should not replace external blinds\/window film\/air-con.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How Heat Enters Through Windows<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Much of the heat that makes a sunny room uncomfortably hot in the summer can be due to sunlight. To understand which blackout curtains will help and which won\u2019t, we need to look at how heat enters through windows.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Radiation \u2013 Sunlight travels through the glass and gets absorbed by the surfaces in your room (floor, walls, furniture, bed etc). This can be a major cause of heat gains in the summer and can be reduced by curtains. Conduction \u2013 The glass gets warm and heat passes through. A curtain can reduce heat transfer by trapping still air between the glass and fabric. Convection \u2013 Warm air rises around your hot window. Any gaps around your curtain will allow the warm air to circulate.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Light blocking doesn\u2019t mean heat blocking. Even if your curtain can block almost all visible light it may offer limited heat reduction. This is because it may be very thin, have a dark backing or have gaps around the edges. If your curtain absorbs the light then it will turn it into heat. You want to reflect the sunlight and ensure your curtain fits well to reduce the other two methods.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Blackouts, Thermal and Room Darkening Curtains<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">There are many <strong><a href=\"https:\/\/loomandfiber.com\/blog\/types-of-curtains\/?utm_source=chatgpt.com\">types of curtains<\/a><\/strong> available to do different jobs. Thermal curtains will help with heat. Take a look at how they\u2019re constructed.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Type<\/th><th>Main job<\/th><th>Light blocked<\/th><th>Heat and insulation<\/th><th>Best for<\/th><\/tr><\/thead><tbody><tr><td>Room-darkening<\/td><td>Soften and reduce light<\/td><td>Partial<\/td><td>Low<\/td><td>Living rooms where some daylight is wanted<\/td><\/tr><tr><td>Standard blackout<\/td><td>Block light<\/td><td>Nearly all (when sealed)<\/td><td>Low to moderate; depends on weight and lining<\/td><td>Bedrooms, nurseries, shift workers<\/td><\/tr><tr><td>Thermal<\/td><td>Slow heat transfer<\/td><td>Partial to high<\/td><td>Moderate to high<\/td><td>Rooms with big temperature swings<\/td><\/tr><tr><td>Thermal blackout (lined or multi-layer)<\/td><td>Both<\/td><td>Nearly all<\/td><td>Highest of the four<\/td><td>Sunny west- and south-facing rooms<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">As a general rule, if you want a cooler room then look for <strong><a href=\"https:\/\/loomandfiber.com\/blog\/curtains-and-drapes-for-living-room\/?utm_source=chatgpt.com\">lined and heavy curtains<\/a><\/strong>. Thermal blackout curtains with a white backing will generally be a good choice.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Factors That Affect How Well Blackout Curtains Block Heat<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">There are four factors to consider when looking at how well your blackout curtains will block heat.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Lining &amp; Backing Colour<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The main factor will be what colour the lining is facing the window. If it\u2019s white or light then more sunlight will be reflected. If it\u2019s dark then it will absorb more light and become warm, causing heat to radiate. This means the colour you can see from the inside matters less. The DOE figure refers to medium-coloured drapes with a white plastic backing.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\" style=\"max-width:700px\"><img loading=\"lazy\" decoding=\"async\" width=\"1536\" height=\"1024\" src=\"https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up.webp\" alt=\"Beige curtain folded back to reveal its white blackout lining.\" class=\"wp-image-9916\" srcset=\"https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up.webp 1536w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-300x200.webp 300w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-1024x683.webp 1024w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-768x512.webp 768w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-630x420.webp 630w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-150x100.webp 150w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-696x464.webp 696w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/White-backing-and-blackout-fabric-close-up-1068x712.webp 1068w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption class=\"wp-element-caption\"><strong>White backing on a beige blackout curtain.<\/strong><\/figcaption><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Weave &amp; Coating<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">There are different ways to create blackout curtains. These will affect how well they block heat:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Triple Weave \u2013 Has a dark yarn in the middle. Provides good darkness and some insulation. No extra coating to peel. Foam\/acrylic coating \u2013 The back of the curtain has an extra coating to stop light. Often the best value for money as long as it\u2019s light coloured. Film\/PVC backed \u2013 Very effective at blocking light; heat reflection depends on the backing\u2019s reflective properties. Less breathability and can be stiff. Lined \u2013 Extra layers to create an air gap.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Fibre &amp; GSM<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Generally the heavier and denser the fabric the better it will be at slowing down heat. However, the weave and lining will also affect this.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Fabric type<\/th><th>Typical GSM<\/th><th>Heat performance<\/th><th>Notes<\/th><\/tr><\/thead><tbody><tr><td>Lightweight polyester blackout<\/td><td>200-280<\/td><td>Moderate<\/td><td>Good light block, limited insulation<\/td><\/tr><tr><td>Mid-weight triple-weave polyester<\/td><td>280-380<\/td><td>Good<\/td><td>The common sweet spot for bedrooms<\/td><\/tr><tr><td>Heavy velvet or chenille<\/td><td>380-540<\/td><td>Very good<\/td><td>Dense pile traps air; can feel heavy and look formal<\/td><\/tr><tr><td>Wool blends<\/td><td>300-400<\/td><td>Very good<\/td><td>Natural fiber traps air; less common and pricier<\/td><\/tr><tr><td>Cotton or linen with blackout lining<\/td><td>250-400<\/td><td>Good with a proper lining<\/td><td>Breathable and cooler to the touch; the lining does the blocking<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">These figures will vary depending on the brand. Use as a guideline.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Things To Look For On Labels<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Backing Colour \u2013 White\/light is best for summer. GSM\/Fabric Weight \u2013 Linings \u2013 Coating \u2013 Triple Weave \u2013 Thermal\/Insulation \u2013 Width Options \u2013 Ensure you can get panels that will fully cover your window with some extra.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Why Your Room May Still Be Hot With Blackout Curtains<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">If your room is still hot with your curtains closed then it\u2019s likely to be one of the following:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li>Not closed in time \u2013 If your curtains are closed after sunlight has hit your floor, walls and furniture then they won\u2019t remove that stored heat. Try closing them before direct sunlight hits your window. 2. Dark Backing \u2013 If the backing is black or dark grey then it will absorb sunlight and radiate heat. 3. Lightweight Fabric \u2013 Light blackout panels will block the light but provide little insulation. 4. Gaps \u2013 If the panels are narrow, leave gaps at the top or don\u2019t reach the sill or floor then warm air will circulate. 5. Hot Glass \u2013 If there\u2019s strong sunlight then your window will become a radiator. If your curtains are hanging against the glass they can become warm too. You want a little gap. 6. Heat Source \u2013 If your roof, west facing wall, appliances and poor ventilation are causing heat issues then this can overcome the effect of your curtains.<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">Can Black Blackout Curtains Make a Room Warmer?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">They can. Dark colours will absorb more sunlight. This will make your curtains warm and the air around them, although they may still reduce heat gain compared with an uncovered window. A white\/light reflective backing will be your best choice. If you really like dark curtains then look for ones with a light lining on the window side.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What Blackout Curtains Won\u2019t Do<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">They won\u2019t actively cool your room below the outside air temperature and won\u2019t fix poor wall or roof insulation or a hot roof. They won\u2019t replace external blinds, reflective window film or air-con on very hot days. If used effectively they will reduce how quickly your room warms up.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">How To Hang Blackout Curtains To Reduce Heat<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The way you hang your curtains can make a big difference. According to the DOE you should hang drapes as close to the window as possible, reaching the sill or floor, and seal the sides.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\" style=\"max-width:700px\"><img loading=\"lazy\" decoding=\"async\" width=\"1536\" height=\"1024\" src=\"https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat.webp\" alt=\"Floor-length blackout curtains with labels showing a wide rod and centre overlap.\" class=\"wp-image-9914\" srcset=\"https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat.webp 1536w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-300x200.webp 300w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-1024x683.webp 1024w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-768x512.webp 768w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-630x420.webp 630w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-150x100.webp 150w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-696x464.webp 696w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Correct-curtain-installation-for-reducing-heat-1068x712.webp 1068w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption class=\"wp-element-caption\"><strong>Wide coverage and overlapping panels help limit gaps.<\/strong><\/figcaption><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Mount wide<\/strong> \u2013 Ensure you have a <strong><a href=\"https:\/\/loomandfiber.com\/blog\/how-to-measure-for-curtain-rods\/?utm_source=chatgpt.com\">wide rod<\/a><\/strong> that extends 4-6 inches beyond each side of the window frame. This will ensure the panels fully cover the glass. <\/li>\n\n\n\n<li><strong>Mount high<\/strong> \u2013 Position the rod close to the ceiling or just above the window frame, and seal the top gap to limit sunlight and air movement from above. <\/li>\n\n\n\n<li><strong><a href=\"https:\/\/loomandfiber.com\/blog\/should-curtains-touch-the-floor\/?utm_source=chatgpt.com\">Floor Length<\/a><\/strong> \u2013 Ensure your curtains <strong><a href=\"https:\/\/loomandfiber.com\/calculators\/curtain-length\/?utm_source=chatgpt.com\">reach the floor (or at least the sill)<\/a><\/strong>. This will reduce air flow along the bottom. <\/li>\n\n\n\n<li><strong><a href=\"https:\/\/loomandfiber.com\/blog\/how-much-wider-should-curtains-be-than-the-window\/?utm_source=chatgpt.com\">Wide Panels<\/a><\/strong> \u2013 Ensure your panels have a <strong><a href=\"https:\/\/loomandfiber.com\/calculators\/curtain-width-fullness\/?utm_source=chatgpt.com\">combined width<\/a><\/strong> of at least 1.5-2 times your window width. This will ensure the fabric is ruffled.<\/li>\n\n\n\n<li><strong>Centre Overlap<\/strong> \u2013 Ensure you have two panels that overlap or meet in the centre. Use magnetic tape or Velcro to seal the centre. <\/li>\n\n\n\n<li><strong>Side Seals<\/strong> \u2013 Use a wraparound rod, side returns or cornice to reduce convection along the edges. <\/li>\n\n\n\n<li><strong>Small Gap<\/strong> \u2013 Ensure you have a small gap between the curtain and glass. Don\u2019t push the fabric up against the hot glass. <\/li>\n\n\n\n<li><strong>Thermal Liner<\/strong> \u2013 Add a thermal liner to give a cheap upgrade. If your curtains are light blocking but feel thin or warm in the sun then this will help. <\/li>\n\n\n\n<li><strong><a href=\"https:\/\/loomandfiber.com\/blog\/how-to-layer-curtains\/?utm_source=chatgpt.com\">Layer Up<\/a><\/strong> \u2013 Add sheers or blinds to give you light control in the day and an extra layer.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">When To Close Them<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Window Orientation<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In the Northern hemisphere your East facing windows will get strong morning sunlight, South facing windows will get high sunlight in the middle of the day and West facing windows will get intense afternoon sunlight when your room is already warm. Start with your west and south facing windows. According to the DOE you should close any window coverings that are getting direct sunlight in the summer.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Simple Routine<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Close your curtains on any windows facing the sun before direct sunlight hits the glass. Keep them closed throughout the hottest part of the day. Open your windows after the sun has gone down to let in cooler air if it is cooler outside than indoors. Close your windows when the outside air becomes warmer than indoors, and close sun-facing curtains before direct sunlight reaches the glass.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Winter &amp; Year Round<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The same fabric that blocks sunlight will also reduce heat loss through cold glass. According to the DOE you should close your drapes at night and on any windows that aren\u2019t getting sunlight. Open them during sunny days to let in solar heating. Heavy\/lined curtains will help the most.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Blackout Curtains Vs Other Ways To Block Heat From Windows<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Blackout curtains are one of the easiest options to block heat from your windows but won\u2019t be the most effective. As a general rule external window coverings will be better than internal ones.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Option<\/th><th>Heat reduction (DOE where cited)<\/th><th>Strengths<\/th><th>Limits<\/th><\/tr><\/thead><tbody><tr><td>Blackout or thermal curtains with light backing<\/td><td>Up to about 33% for medium-colored drapes with white backing<\/td><td>Cheap, no installation, also block light and add privacy<\/td><td>Interior; performance depends on fit and color<\/td><\/tr><tr><td>Reflective blinds, fully closed<\/td><td>Around 45%<\/td><td>Adjustable slats; good on sunny windows<\/td><td>Gaps between slats; less insulation in winter<\/td><\/tr><tr><td>Cellular (honeycomb) shades<\/td><td>Often cited as among the best interior options<\/td><td>Trapped air cells insulate in both seasons<\/td><td>Higher cost; need an accurate fit<\/td><\/tr><tr><td>Solar shades<\/td><td>Varies by openness<\/td><td>Cut glare and heat while keeping some view<\/td><td>Don&#8217;t give full darkness<\/td><\/tr><tr><td>Reflective window film<\/td><td>Varies by film; check NFRC ratings<\/td><td>Works at the glass, keeps daylight<\/td><td>Permanent; can alter the view and appearance<\/td><\/tr><tr><td>Exterior awnings<\/td><td>Up to 65% (south-facing) and 77% (west-facing)<\/td><td>Stop sun before it reaches the glass<\/td><td>Cost and installation; not available to everyone<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Best Combinations<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Blackout Curtains + <strong><a href=\"https:\/\/loomandfiber.com\/blog\/do-sheer-curtains-provide-privacy\/?utm_source=chatgpt.com\">Sheers<\/a><\/strong>\/Blinds \u2013 Use blinds during the middle of the day and blackout curtains for full darkness at night. Cellular Shades + Curtains \u2013 A strong combination for large windows. Film + Curtains \u2013 Solar-control film will reduce solar heat gain through the glass throughout the day. Curtains will help with darkness and insulation during winter. External Shading + Anything \u2013 The most effective option for badly overheating rooms.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\" style=\"max-width:700px\"><img loading=\"lazy\" decoding=\"async\" width=\"1536\" height=\"1024\" src=\"https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains.webp\" alt=\"White cellular shade behind beige blackout curtains in a neutral living room.\" class=\"wp-image-9912\" srcset=\"https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains.webp 1536w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-300x200.webp 300w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-1024x683.webp 1024w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-768x512.webp 768w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-630x420.webp 630w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-150x100.webp 150w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-696x464.webp 696w, https:\/\/loomandfiber.com\/blog\/wp-content\/uploads\/2026\/11\/Cellular-shades-layered-with-blackout-curtains-1068x712.webp 1068w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption class=\"wp-element-caption\"><strong>Cellular shades paired with blackout curtains.<\/strong><\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center\">FAQs<\/h2>\n\n\n\n<div class=\"schema-faq wp-block-yoast-faq-block\"><div class=\"schema-faq-section\" id=\"faq-question-1793911215624\"><strong class=\"schema-faq-question\">Do Blackout Curtains Block Heat?<\/strong> <p class=\"schema-faq-answer\">Yes. They block sunlight to reduce heat. Medium-coloured drapes with a white plastic backing can reduce heat gains by up to 33%, according to the DOE. Using a light backing, a tight fit and good timing will give the best results.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1793911230074\"><strong class=\"schema-faq-question\">Do Blackout Curtains Make A Room Warmer?<\/strong> <p class=\"schema-faq-answer\">They can. If your backing is dark then it can absorb sunlight and release heat into the room, although the curtains may still reduce heat gain compared with an uncovered window. Dark colours absorb sunlight and turn it into heat.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1793911245407\"><strong class=\"schema-faq-question\">What Colour Should My Blackout Curtains Be To Block Heat?<\/strong> <p class=\"schema-faq-answer\">White\/light on the window side. The front matters less. White backed curtains will reflect more sunlight. Dark backed curtains will absorb more sunlight.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1793911264898\"><strong class=\"schema-faq-question\">Are Thermal Curtains Better For Summer Heat Than Blackout?<\/strong> <p class=\"schema-faq-answer\">Thermal blackout curtains will generally be a good option. They do both! Blackout curtains will block the light but thermal curtains will reduce heat transfer. Look for lined or multiple layered curtains.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1793911287983\"><strong class=\"schema-faq-question\">Why Is My Room Still Warm With Blackout Curtains Closed?<\/strong> <p class=\"schema-faq-answer\">It\u2019s likely to be due to closing them too late, dark backing, lightweight fabric, gaps on the sides and hot glass. Ensure they fit well and are closed at the right time.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1793911307668\"><strong class=\"schema-faq-question\">Do Blackout Curtains Work In Winter?<\/strong> <p class=\"schema-faq-answer\">Yes. Heavy\/lined curtains will reduce heat loss through cold glass. Close them at night and open during sunny days to let in solar heating.<\/p> <\/div> <div class=\"schema-faq-section\" id=\"faq-question-1793911341248\"><strong class=\"schema-faq-question\">Are Blackout Curtains Better Than Blinds?<\/strong> <p class=\"schema-faq-answer\">It depends. Highly reflective blinds that are fully lowered with closed slats can reduce solar heat gain by around 45%, according to the DOE. Cellular shades are good at insulation. Blackout curtains provide full darkness when properly fitted and can help with insulation during winter. Layering both together works well.<\/p> <\/div> <\/div>\n","protected":false},"excerpt":{"rendered":"<p>Do Blackout Curtains Block Heat? Yes, but to some extent. Blackout curtains prevent sunlight from reaching surfaces within your room, which reduces the amount of heat those surfaces absorb. Medium-coloured drapes with a white plastic backing can reduce heat gains by up to 33%, according to the U.S. Department of Energy. Whether or not you\u2019ll [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":9911,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-9906","post","type-post","status-publish","format-standard","has-post-thumbnail","category-curtains-drapes"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.8 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Do Blackout Curtains Block Heat? 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They block sunlight to reduce heat. Medium-coloured drapes with a white plastic backing can reduce heat gains by up to 33%, according to the DOE. Using a light backing, a tight fit and good timing will give the best results.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911230074","position":2,"url":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911230074","name":"Do Blackout Curtains Make A Room Warmer?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"They can. If your backing is dark then it can absorb sunlight and release heat into the room, although the curtains may still reduce heat gain compared with an uncovered window. Dark colours absorb sunlight and turn it into heat.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911245407","position":3,"url":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911245407","name":"What Colour Should My Blackout Curtains Be To Block Heat?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"White\/light on the window side. The front matters less. White backed curtains will reflect more sunlight. Dark backed curtains will absorb more sunlight.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911264898","position":4,"url":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911264898","name":"Are Thermal Curtains Better For Summer Heat Than Blackout?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Thermal blackout curtains will generally be a good option. They do both! Blackout curtains will block the light but thermal curtains will reduce heat transfer. Look for lined or multiple layered curtains.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911287983","position":5,"url":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911287983","name":"Why Is My Room Still Warm With Blackout Curtains Closed?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"It\u2019s likely to be due to closing them too late, dark backing, lightweight fabric, gaps on the sides and hot glass. Ensure they fit well and are closed at the right time.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911307668","position":6,"url":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911307668","name":"Do Blackout Curtains Work In Winter?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"Yes. Heavy\/lined curtains will reduce heat loss through cold glass. Close them at night and open during sunny days to let in solar heating.","inLanguage":"en-US"},"inLanguage":"en-US"},{"@type":"Question","@id":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911341248","position":7,"url":"https:\/\/loomandfiber.com\/blog\/do-blackout-curtains-block-heat\/#faq-question-1793911341248","name":"Are Blackout Curtains Better Than Blinds?","answerCount":1,"acceptedAnswer":{"@type":"Answer","text":"It depends. Highly reflective blinds that are fully lowered with closed slats can reduce solar heat gain by around 45%, according to the DOE. Cellular shades are good at insulation. Blackout curtains provide full darkness when properly fitted and can help with insulation during winter. Layering both together works well.","inLanguage":"en-US"},"inLanguage":"en-US"}]}},"_links":{"self":[{"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/posts\/9906","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/comments?post=9906"}],"version-history":[{"count":6,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/posts\/9906\/revisions"}],"predecessor-version":[{"id":9917,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/posts\/9906\/revisions\/9917"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/media\/9911"}],"wp:attachment":[{"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/media?parent=9906"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/categories?post=9906"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/loomandfiber.com\/blog\/wp-json\/wp\/v2\/tags?post=9906"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}