{"id":997599,"date":"2026-10-21T08:00:00","date_gmt":"2026-10-21T06:00:00","guid":{"rendered":"https:\/\/kienzler-klima.de\/?p=997599"},"modified":"2026-08-19T11:26:25","modified_gmt":"2026-08-19T09:26:25","slug":"how-to-tell-if-ventilation-system-causes-drafts","status":"publish","type":"post","link":"https:\/\/kienzler-klima.de\/en\/how-to-tell-if-ventilation-system-causes-drafts\/","title":{"rendered":"How to tell if your ventilation system is causing draughts"},"content":{"rendered":"<div class=\"vgblk-rw-wrapper limit-wrapper\">\n<p>Drafts from the ventilation system can be identified by a noticeable, persistent airflow in the occupied zone, even when no windows or doors are open. The most common sign is an air velocity exceeding 0.2 m\/s at body height, combined with an uncomfortable sensation of cold on the skin or neck. The following sections show how to systematically diagnose drafts, narrow down the causes, and eliminate them permanently.<\/p>\n<h2>What symptoms indicate drafts from the ventilation system?<\/h2>\n<p>Drafts from the ventilation system typically manifest as a perceptible, directional airflow at body height that occurs independently of external influences. Those affected frequently report a cold sensation in the neck or shoulder area, dry eyes or mucous membranes, and a general sense of discomfort that is difficult to pinpoint precisely.<\/p>\n<p>Typical symptoms at a glance:<\/p>\n<ul>\n<li><strong>Noticeable draft<\/strong> at certain workstations or in certain areas of a room, even though no windows are open<\/li>\n<li><strong>Uneven temperature distribution<\/strong> in the room, with individual zones feeling noticeably cooler than others<\/li>\n<li><strong>Fluttering papers or curtains<\/strong> near air outlets<\/li>\n<li><strong>Increased sick leave rates<\/strong> or frequent complaints about neck tension and cold symptoms among room occupants<\/li>\n<li><strong>Noises from the ventilation duct<\/strong> indicating excessively high flow velocities<\/li>\n<\/ul>\n<p>Important: Not every perceived draft originates directly from the ventilation system. Leaky windows, door gaps, or thermal convection from cold exterior walls can trigger similar sensations. For this reason, a targeted diagnosis is essential before any measures are taken.<\/p>\n<h2>How do you measure air velocity to diagnose drafts?<\/h2>\n<p>To diagnose drafts from the ventilation system, air velocity is measured using an anemometer. Measurement is recommended at body height, i.e., approximately 1.0 to 1.2 meters above the floor, at multiple points in the room, particularly near air outlets and in regularly used occupied areas.<\/p>\n<p>As a guideline: air velocities above <strong>0.15 to 0.2 m\/s<\/strong> in the occupied zone are perceived as uncomfortable by many people, especially when the air is cooler than the ambient temperature. DIN EN ISO 7730 and VDI 6022 provide specific comfort threshold values for this purpose.<\/p>\n<p>The following steps are recommended for a meaningful measurement:<\/p>\n<ol>\n<li>Run the system in normal operation mode, do not activate any special settings<\/li>\n<li>Define multiple measurement points in the room, particularly below and beside air outlets<\/li>\n<li>Carry out measurements at different heights (foot level, seated level, head level)<\/li>\n<li>Document results and compare them with the system&#8217;s design values<\/li>\n<li>Simultaneously record the temperature difference between supply air and room air<\/li>\n<\/ol>\n<p>A simple smoke pencil or incense stick can additionally help to visualize the direction of airflow, which is particularly useful when a draft is felt in an area not directly beneath an outlet.<\/p>\n<h2>What are the most common causes of drafts in ventilation systems?<\/h2>\n<p>The most common causes of drafts in ventilation systems are excessively high discharge velocities at the air outlets, incorrect alignment of airflows, and an inadequately sized or incorrectly positioned distribution system. Operational causes such as an excessively high volume flow rate or a clogged filter that increases pressure loss in the system also play a role.<\/p>\n<p>The following causes are particularly prevalent:<\/p>\n<ul>\n<li><strong>Excessively high discharge velocity:<\/strong> Conventional slot outlets or nozzles produce concentrated air jets that, when incorrectly installed or operating at too high a volume flow, strike directly into the occupied zone.<\/li>\n<li><strong>Incorrect alignment of outlets:<\/strong> When air is directed straight at workstations or seating areas, drafts are inevitable, regardless of the volume flow rate.<\/li>\n<li><strong>Excessive temperature difference between supply air and room air:<\/strong> Cool supply air sinks more rapidly and reaches the occupied zone at a noticeable velocity.<\/li>\n<li><strong>Dirty or defective components:<\/strong> Clogged filters or damaged outlets alter the flow pattern and can create localized draft conditions.<\/li>\n<li><strong>Incorrect commissioning:<\/strong> If volume flow rates were not properly balanced after installation, the system operates outside its design parameters.<\/li>\n<\/ul>\n<p>With <a href=\"https:\/\/kienzler-klima.de\/en\/textile-air-ducts-basics\/\">textile air distribution systems<\/a>, the risk of drafts is significantly lower by design, as air exits over the entire surface of the duct in a large-area, very low-velocity manner rather than as a concentrated jet.<\/p>\n<h2>When is a draft a sign of incorrectly designed ventilation components?<\/h2>\n<p>A draft is a sign of incorrectly designed ventilation components when it persists despite correct balancing and a clean filter condition. In this case, the problem lies not in the operation but already in the planning \u2014 for example, in the choice of the wrong outlet type, an unsuitable positioning, or undersizing of the discharge cross-sections.<\/p>\n<p>Specific indicators of a design error include:<\/p>\n<ul>\n<li>Drafts occur from the very beginning, i.e., already during the first regular operation after commissioning<\/li>\n<li>Air velocity in the occupied zone exceeds comfort threshold values even at minimum volume flow<\/li>\n<li>The draft is concentrated in specific areas of the room that were designated as occupied zones in the planning<\/li>\n<li>Subsequent adjustments to dampers or volume flow controllers bring no lasting improvement<\/li>\n<\/ul>\n<p>Incorrect design is particularly critical in sensitive areas such as laboratories, hospitals, or offices, where comfort directly affects the productivity and health of occupants. In such cases, a renewed hydraulic calculation and, if necessary, replacement of the air outlets is unavoidable. An overview of suitable <a href=\"https:\/\/kienzler-klima.de\/en\/can-be-used-in-all-areas-and-industries\/\">application areas for textile systems<\/a> can be found on our industry page.<\/p>\n<h2>How can drafts from the ventilation system be permanently resolved?<\/h2>\n<p>Drafts from the ventilation system can be permanently resolved by reducing the discharge velocity, adjusting the airflow routing, and, if necessary, replacing the air outlets with more suitable components. Short-term measures such as covering outlets are not a sustainable solution \u2014 they alter the flow pattern in an uncontrolled manner and can lead to other problems.<\/p>\n<p>Proven measures for permanent resolution:<\/p>\n<ul>\n<li><strong>Reduce volume flow<\/strong> and repeat hydraulic balancing<\/li>\n<li><strong>Correct the discharge direction of the outlets<\/strong> \u2014 air should be guided along the ceiling or wall, not directly into the occupied zone<\/li>\n<li><strong>Use larger discharge cross-sections<\/strong> to reduce flow velocity at the same volume flow rate<\/li>\n<li><strong>Raise supply air temperature<\/strong> to reduce the temperature difference with the room air and minimize the sinking of supply air<\/li>\n<li><strong>Switch to a large-area air distribution system<\/strong> that delivers air evenly and at low velocity over a large surface<\/li>\n<\/ul>\n<p>The most effective approach is often a system change: <a href=\"https:\/\/kienzler-klima.de\/en\/countless-variation-options\/\">Textile air ducts<\/a> distribute air evenly along their entire length through the permeability of the fabric, with discharge velocities well below the draft threshold. This makes draft conditions structurally almost impossible.<\/p>\n<h2>How we can help you with drafts in your ventilation system<\/h2>\n<p>At Kienzler Klima, we have been developing textile air distribution systems for over 30 years \u2014 systems that not only reduce drafts but eliminate them by design. Our solutions are individually tailored to every application, from the initial consultation through to the fully installed system.<\/p>\n<p>What we do specifically for you:<\/p>\n<ul>\n<li><strong>Individual design<\/strong> of every textile duct based on your room geometry, volume flow rate, and comfort requirements<\/li>\n<li><strong>Draft-free air distribution<\/strong> through large-area, permeable textile systems with very low discharge velocities<\/li>\n<li><strong>Short delivery times<\/strong> averaging 14 days, manufactured in Germany, in the Allg\u00e4u region<\/li>\n<li><strong>Up to 60% savings<\/strong> on material and installation costs compared to conventional sheet metal systems<\/li>\n<li><strong>Cradle-to-Cradle certified<\/strong> with permanent, chemically anchored fire protection \u2014 without compromising on safety or sustainability<\/li>\n<\/ul>\n<p>If you notice drafts in your system or are planning a new ventilation system, please get in touch with us. <a href=\"https:\/\/kienzler-klima.de\/en\/contact-us\/\">Contact us<\/a> \u2014 we will advise you without obligation and work with you to find the right solution for your project.<\/p>\n<\/div>\n<p><!-- .vgblk-rw-wrapper --><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Detect drafts from your ventilation system, pinpoint the causes, and fix them for good. Here&#8217;s how.<\/p>\n","protected":false},"author":13,"featured_media":999548,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-997599","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-unkategorisiert"],"acf":[],"_links":{"self":[{"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/posts\/997599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/comments?post=997599"}],"version-history":[{"count":1,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/posts\/997599\/revisions"}],"predecessor-version":[{"id":997721,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/posts\/997599\/revisions\/997721"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/media\/999548"}],"wp:attachment":[{"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/media?parent=997599"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/categories?post=997599"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kienzler-klima.de\/en\/wp-json\/wp\/v2\/tags?post=997599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}