{"id":3904,"date":"2023-04-05T19:04:06","date_gmt":"2023-04-05T13:34:06","guid":{"rendered":"https:\/\/aluminiummagazine.com\/mag\/?p=3904"},"modified":"2026-04-03T02:15:40","modified_gmt":"2026-04-02T20:45:40","slug":"kelvink-value-of-doors-and-windows","status":"publish","type":"post","link":"https:\/\/aluminiummagazine.com\/mag\/efficiency\/kelvink-value-of-doors-and-windows.html","title":{"rendered":"Kelvin (K) Value in Windows: What It Means (and What It Doesn\u2019t)"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">When you\u2019re selecting high\u2011performance doors and windows, you\u2019ll often come across the term <strong>Kelvin (K)<\/strong> . But there\u2019s a common misunderstanding: Kelvin is frequently mistaken for a measure of thermal performance. In reality, it serves a completely different purpose.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let\u2019s clear up the confusion\u2014and then focus on the numbers that actually matter for energy efficiency, comfort, and durability.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What Kelvin (K) Actually Measures<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Kelvin is often misunderstood in windows \u2014 <strong>it only describes light colour, not heat performance.<\/strong><\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">In architectural and interior contexts, Kelvin defines the <strong>colour temperature of light<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>2700K \u2013 3000K<\/strong> \u2192 Warm, yellowish glow (cozy, residential feel)<\/li>\n\n\n\n<li><strong>5000K \u2013 6500K<\/strong> \u2192 Cool, bluish light (task\u2011oriented, commercial spaces)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">So when someone asks about the \u201cKelvin value\u201d of a window, they\u2019re asking about the <em>light source behind it<\/em>\u2014not how well the window insulates your home.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>The Real Metrics: U\u2011Factor, SHGC, and VT<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">To evaluate how a window or door performs, professionals rely on three key numbers. These determine whether a building stays comfortable, energy\u2011efficient, and cost\u2011effective.<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">1. U\u2011Factor (Thermal Transmittance)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The U\u2011factor measures how much heat escapes through a window, door, or skylight.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>It includes heat transfer through the glass, the frame, and the edges.<\/strong><\/li>\n\n\n\n<li><strong>Lower is better<\/strong> \u2013 a low U\u2011factor means superior insulation and lower energy bills.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For thermally broken aluminium systems, a low U\u2011factor is a direct indicator of quality.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. Solar Heat Gain Coefficient (SHGC)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">SHGC measures how much solar radiation (heat from the sun) passes through a window.<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<ul class=\"wp-block-list\">\n<li>It ranges from <strong>0 to 1<\/strong> \u2013 a lower value means less solar heat enters.<\/li>\n\n\n\n<li><strong>Low SHGC<\/strong> is ideal for hot climates (like Australia, Texas, or the Middle East) to reduce cooling loads.<\/li>\n\n\n\n<li><strong>High SHGC<\/strong> can be beneficial in cold climates where passive solar heating is desired.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. Visible Transmittance (VT)<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">VT indicates how much visible light comes through the glass.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>High VT = more daylight, less need for artificial lighting.<\/strong><\/li>\n\n\n\n<li>It\u2019s often a balancing act: low\u2011E coatings may lower SHGC (good for heat control) but can slightly reduce VT.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">The Bottom Line: Looks vs. Feel<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In short: Kelvin controls how your home <em>looks<\/em>, while U\u2011factor and SHGC control how your home <em>feels<\/em>.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When specifying or buying aluminium windows, always ask for the <strong>U\u2011factor, SHGC, and VT<\/strong> data. These numbers tell you the real story about energy efficiency, comfort, and climate suitability\u2014whether you\u2019re installing bifold doors in Queensland or thermal\u2011break windows in Canada.<\/p><div class=\"pai-ad\" style=\"min-height:250px;visibility:hidden;\"><span style=\"display: block; text-align: center; font-size: 10px; margin: 0 0 10px 0; color: #999999;\">Ads<\/span>\r\n<!-- Display-300x250-1 -->\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:inline-block;width:300px;height:250px\"\r\n     data-ad-client=\"ca-pub-3838168351244230\"\r\n     data-ad-slot=\"9933646018\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script><\/div>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Further Reading:<\/h2>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-aluminium-magazine wp-block-embed-aluminium-magazine\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"NDALxeFEPy\"><a href=\"https:\/\/aluminiummagazine.com\/mag\/efficiency\/comparing-shgc-and-u-factor-which-is-more-important-when-choosing-windows.html\">SHGC and U-Value of Windows and Doors for Optimal Energy Efficiency<\/a><\/blockquote><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;SHGC and U-Value of Windows and Doors for Optimal Energy Efficiency&#8221; &#8212; Aluminium Magazine\" src=\"https:\/\/aluminiummagazine.com\/mag\/efficiency\/comparing-shgc-and-u-factor-which-is-more-important-when-choosing-windows.html\/embed#?secret=SMzWDTm5mP#?secret=NDALxeFEPy\" data-secret=\"NDALxeFEPy\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-aluminium-magazine wp-block-embed-aluminium-magazine\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"4QHKS1ReOF\"><a href=\"https:\/\/aluminiummagazine.com\/mag\/efficiency\/thermal-break-windows-vs-double-glazing-due-for-energy-efficiency.html\">Confused About Thermal Break Windows &amp; Double Glazing<\/a><\/blockquote><iframe class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;Confused About Thermal Break Windows &amp; Double Glazing&#8221; &#8212; Aluminium Magazine\" src=\"https:\/\/aluminiummagazine.com\/mag\/efficiency\/thermal-break-windows-vs-double-glazing-due-for-energy-efficiency.html\/embed#?secret=rJfhU2lhZM#?secret=4QHKS1ReOF\" data-secret=\"4QHKS1ReOF\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n<\/div>\n<\/div>\n<\/p><script>document.addEventListener(\"DOMContentLoaded\",function(){\n        if(window.innerWidth <= 768){\n            if (\"immediate\" === \"delay\") {\n                setTimeout(function(){document.querySelectorAll(\".pai-ad\").forEach(el=>el.style.visibility=\"visible\")},0);\n            } else if (\"immediate\" === \"scroll\") {\n                window.addEventListener(\"scroll\",function(){\n                    let s=window.scrollY\/(document.body.scrollHeight-window.innerHeight);\n                    if(s>0.1){\n                        document.querySelectorAll(\".pai-ad\").forEach(el=>el.style.visibility=\"visible\");\n                    }\n                });\n            } else {\n                document.querySelectorAll(\".pai-ad\").forEach(el=>el.style.visibility=\"visible\");\n            }\n        } else {\n            document.querySelectorAll(\".pai-ad\").forEach(el=>el.remove());\n        }\n    });<\/script>","protected":false},"excerpt":{"rendered":"<p>When you\u2019re selecting high\u2011performance doors and windows, you\u2019ll often come across the term Kelvin (K) . But there\u2019s a common misunderstanding: Kelvin is frequently mistaken for a measure of thermal performance. In reality, it serves a completely different purpose. Let\u2019s clear up the confusion\u2014and then focus on the numbers that actually matter for energy efficiency, &#8230; <a title=\"Kelvin (K) Value in Windows: What It Means (and What It Doesn\u2019t)\" class=\"read-more\" href=\"https:\/\/aluminiummagazine.com\/mag\/efficiency\/kelvink-value-of-doors-and-windows.html\" aria-label=\"Read more about Kelvin (K) Value in Windows: What It Means (and What It Doesn\u2019t)\">Read more<\/a><\/p>\n","protected":false},"author":12,"featured_media":17517,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[791,46,45,139,1804],"tags":[4137,4134],"class_list":["post-3904","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-efficiency","category-doors","category-windows","category-knowledge","category-magazine","tag-kelvin-value","tag-kelvin-value-of-doors-and-windows"],"_links":{"self":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/posts\/3904","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/comments?post=3904"}],"version-history":[{"count":0,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/posts\/3904\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/media\/17517"}],"wp:attachment":[{"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/media?parent=3904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/categories?post=3904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aluminiummagazine.com\/mag\/wp-json\/wp\/v2\/tags?post=3904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}