{"id":9281,"date":"2019-09-29T11:26:21","date_gmt":"2019-09-29T16:26:21","guid":{"rendered":"https:\/\/www.kele.com\/content\/?p=9281"},"modified":"2022-02-10T08:48:15","modified_gmt":"2022-02-10T14:48:15","slug":"considerations-for-selecting-a-smoke-duct-detector","status":"publish","type":"post","link":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector","title":{"rendered":"Considerations for Selecting a Duct Smoke Detector"},"content":{"rendered":"<p>[et_pb_section bb_built=&#8221;1&#8243;][et_pb_row][et_pb_column type=&#8221;4_4&#8243;][et_pb_text _builder_version=&#8221;3.2.1&#8243;]<\/p>\n<p>HVAC air ducts transfer conditioned air to occupied spaces in a building. In the event of a fire, air ducts can also transfer harmful\u2014and even deadly\u2014smoke, toxic gases, and flames to those same occupied spaces. National and local safety codes and standards address this issue by specifying the use of duct smoke detectors to help prevent injury, panic, and property damage. To prevent the spread and recirculation of smoke and other products of combustion, duct smoke detectors are used to shut off air handling systems, fans, and blowers when necessary. Duct detectors are often connected to the building\u2019s fire alarm system and may also be a part of a control system designed to exhaust smoke to the outside of the building. Duct smoke detectors are not to be used as a substitute for open area protection or early warning detection nor are they a substitute for a building\u2019s regular fire detection system.<\/p>\n<p>To detect smoke, detectors consisting of a sensor within an enclosure are mounted outside of the duct. Sampling tubes connected to the detector enclosure penetrate and traverse the duct to draw air into the detector, sample it, and then return it<br \/>\nto the air stream. When particles of smoke suspended in the air reach the alarm threshold of the detector, an alarm signal is initiated, and appropriate action can be taken to turn off equipment and alert the building\u2019s fire alarm control panel.<\/p>\n<p>Regardless of the sensing technology used, a duct smoke detector must be installed in a location that will ensure the detector monitors representative samples of<br \/>\nair flowing through the duct. There are several factors to be considered when selecting a detector location in a duct.<\/p>\n<ul>\n<li><strong>Dilution<\/strong>: Duct smoke detectors will alarm only when combustion particles make up a specified percentage of the sampled air. If circulated air mixes with fresh outside air, the combustion particle concentration can dilute and prevent a detector from sensing a fire condition. To avoid dilution, detectors should be located before fresh air intakes and before the exhaust air output.<\/li>\n<\/ul>\n<ul>\n<li><strong>Stratification<\/strong>: Within a duct, air and combustion particles may stratify, preventing proper air sampling. To get a representative air sample, locate the detector between six and 10 duct widths downstream from a bend or other obstruction in the duct.<strong>\u00a0<\/strong><\/li>\n<\/ul>\n<ul>\n<li><strong>Excess humidity<\/strong>: High levels of humidity or condensation within the duct can cause false alarms. Duct smoke detectors should be located a minimum of 10 feet downstream of humidifiers.<strong>\u00a0<\/strong><\/li>\n<\/ul>\n<ul>\n<li><strong>Air filters<\/strong>: Air filters within ducts tend to collect flammable materials<br \/>\nlike paper, lint, and trash. Detectors should be installed downstream of filters to detect fires occurring in the filters. Regular filter maintenance is critical since reduced air flow due to clogged filters could prevent correct operation of the duct detector.<strong>\u00a0<\/strong><\/li>\n<\/ul>\n<ul>\n<li><strong>Air velocity<\/strong>: Duct smoke detectors are designed to be used in air handling systems having a certain range of air velocities, usually 500 to 4000 fpm. For applications down to 100 fpm, low-flow technology detectors are available.<\/li>\n<\/ul>\n<p>Finally, when applying, installing, testing, and maintaining duct smoke detectors, be careful to follow the detector manufacturer\u2019s instructions and adhere to National Fire Protection Association standards National Fire Alarm Code (NFPA 72) and Standard for the Installation of Air Conditioning and Ventilating Systems (NFPA 90A). Copies of the standards can be ordered from <a href=\"http:\/\/www.nfpa.org\">www.nfpa.org<\/a>.<\/p>\n<p><a href=\"https:\/\/www.kele.com\/gas-and-specialty-sensors\/duct-smoke.aspx\" target=\"_blank\" rel=\"noopener\">Kele offers a variety of duct smoke detectors and accessories.<\/a><\/p>\n<p>[\/et_pb_text][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>\n","protected":false},"excerpt":{"rendered":"<p>HVAC air ducts transfer conditioned air to occupied&#8230;<\/p>\n","protected":false},"author":3,"featured_media":9307,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[5],"tags":[],"class_list":["post-9281","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-insights"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\r\n<title>Considerations for Selecting a Duct Smoke Detector - kele.com<\/title>\r\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\r\n<link rel=\"canonical\" href=\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\" \/>\r\n<meta property=\"og:locale\" content=\"en_US\" \/>\r\n<meta property=\"og:type\" content=\"article\" \/>\r\n<meta property=\"og:title\" content=\"Considerations for Selecting a Duct Smoke Detector - kele.com\" \/>\r\n<meta property=\"og:description\" content=\"HVAC air ducts transfer conditioned air to occupied...\" \/>\r\n<meta property=\"og:url\" content=\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\" \/>\r\n<meta property=\"og:site_name\" content=\"kele.com\" \/>\r\n<meta property=\"article:published_time\" content=\"2019-09-29T16:26:21+00:00\" \/>\r\n<meta property=\"article:modified_time\" content=\"2022-02-10T14:48:15+00:00\" \/>\r\n<meta property=\"og:image\" content=\"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg\" \/>\r\n\t<meta property=\"og:image:width\" content=\"500\" \/>\r\n\t<meta property=\"og:image:height\" content=\"194\" \/>\r\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\r\n<meta name=\"author\" content=\"Kele Inc\" \/>\r\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\r\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Kele Inc\" \/>\r\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\"},\"author\":{\"name\":\"Kele Inc\",\"@id\":\"https:\/\/www.kele.com\/content\/#\/schema\/person\/759cbd0e294ee37f0c4cd2630505e0cd\"},\"headline\":\"Considerations for Selecting a Duct Smoke Detector\",\"datePublished\":\"2019-09-29T16:26:21+00:00\",\"dateModified\":\"2022-02-10T14:48:15+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\"},\"wordCount\":597,\"commentCount\":0,\"image\":{\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage\"},\"thumbnailUrl\":\"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg\",\"articleSection\":[\"Insights\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\",\"url\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\",\"name\":\"Considerations for Selecting a Duct Smoke Detector - kele.com\",\"isPartOf\":{\"@id\":\"https:\/\/www.kele.com\/content\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage\"},\"thumbnailUrl\":\"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg\",\"datePublished\":\"2019-09-29T16:26:21+00:00\",\"dateModified\":\"2022-02-10T14:48:15+00:00\",\"author\":{\"@id\":\"https:\/\/www.kele.com\/content\/#\/schema\/person\/759cbd0e294ee37f0c4cd2630505e0cd\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage\",\"url\":\"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg\",\"contentUrl\":\"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg\",\"width\":500,\"height\":194,\"caption\":\"Young man in orange work vest, safety belt and hard hat going to repair HVAC system. Toned photography.\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.kele.com\/content\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Considerations for Selecting a Duct Smoke Detector\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.kele.com\/content\/#website\",\"url\":\"https:\/\/www.kele.com\/content\/\",\"name\":\"kele.com\",\"description\":\"Kele is a single source supplier with a huge inventory for all your building automation requirements. In-stock items ship same day, 3-day standard shipping.\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.kele.com\/content\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.kele.com\/content\/#\/schema\/person\/759cbd0e294ee37f0c4cd2630505e0cd\",\"name\":\"Kele Inc\",\"url\":\"https:\/\/www.kele.com\/content\/blog\/author\/keleinc\/\"}]}<\/script>\r\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Considerations for Selecting a Duct Smoke Detector - kele.com","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector","og_locale":"en_US","og_type":"article","og_title":"Considerations for Selecting a Duct Smoke Detector - kele.com","og_description":"HVAC air ducts transfer conditioned air to occupied...","og_url":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector","og_site_name":"kele.com","article_published_time":"2019-09-29T16:26:21+00:00","article_modified_time":"2022-02-10T14:48:15+00:00","og_image":[{"width":500,"height":194,"url":"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg","type":"image\/jpeg"}],"author":"Kele Inc","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Kele Inc"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#article","isPartOf":{"@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector"},"author":{"name":"Kele Inc","@id":"https:\/\/www.kele.com\/content\/#\/schema\/person\/759cbd0e294ee37f0c4cd2630505e0cd"},"headline":"Considerations for Selecting a Duct Smoke Detector","datePublished":"2019-09-29T16:26:21+00:00","dateModified":"2022-02-10T14:48:15+00:00","mainEntityOfPage":{"@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector"},"wordCount":597,"commentCount":0,"image":{"@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage"},"thumbnailUrl":"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg","articleSection":["Insights"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector","url":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector","name":"Considerations for Selecting a Duct Smoke Detector - kele.com","isPartOf":{"@id":"https:\/\/www.kele.com\/content\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage"},"image":{"@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage"},"thumbnailUrl":"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg","datePublished":"2019-09-29T16:26:21+00:00","dateModified":"2022-02-10T14:48:15+00:00","author":{"@id":"https:\/\/www.kele.com\/content\/#\/schema\/person\/759cbd0e294ee37f0c4cd2630505e0cd"},"breadcrumb":{"@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#primaryimage","url":"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg","contentUrl":"https:\/\/assets.kele.com\/content\/wp-content\/uploads\/2019\/09\/DuctWork.jpg","width":500,"height":194,"caption":"Young man in orange work vest, safety belt and hard hat going to repair HVAC system. Toned photography."},{"@type":"BreadcrumbList","@id":"https:\/\/www.kele.com\/content\/blog\/considerations-for-selecting-a-smoke-duct-detector#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.kele.com\/content\/"},{"@type":"ListItem","position":2,"name":"Considerations for Selecting a Duct Smoke Detector"}]},{"@type":"WebSite","@id":"https:\/\/www.kele.com\/content\/#website","url":"https:\/\/www.kele.com\/content\/","name":"kele.com","description":"Kele is a single source supplier with a huge inventory for all your building automation requirements. In-stock items ship same day, 3-day standard shipping.","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.kele.com\/content\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.kele.com\/content\/#\/schema\/person\/759cbd0e294ee37f0c4cd2630505e0cd","name":"Kele Inc","url":"https:\/\/www.kele.com\/content\/blog\/author\/keleinc\/"}]}},"_links":{"self":[{"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/posts\/9281","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/comments?post=9281"}],"version-history":[{"count":0,"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/posts\/9281\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/media\/9307"}],"wp:attachment":[{"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/media?parent=9281"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/categories?post=9281"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.kele.com\/content\/wp-json\/wp\/v2\/tags?post=9281"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}