{"id":9210,"date":"2026-11-03T12:40:19","date_gmt":"2026-11-03T10:40:19","guid":{"rendered":"https:\/\/www.bunker-bssd.de\/2026\/11\/03\/bunker-ventilation-how-ventilation-and-nbc-filter-systems-work\/"},"modified":"2026-11-05T17:33:03","modified_gmt":"2026-11-05T15:33:03","slug":"bunker-ventilation-how-ventilation-and-nbc-filter-systems-work","status":"publish","type":"post","link":"https:\/\/www.bunker-bssd.de\/en\/2026\/11\/03\/bunker-ventilation-how-ventilation-and-nbc-filter-systems-work\/","title":{"rendered":"Bunker Ventilation: How Ventilation and NBC Filter Systems Work"},"content":{"rendered":"\t<div class=\"img has-hover x md-x lg-x y md-y lg-y\" id=\"image_691818510\">\n\t\t\t\t\t\t\t\t<div class=\"img-inner dark\" style=\"margin:0px 0px 25px 0px;\">\n\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"1020\" height=\"680\" src=\"https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-1200x800.jpg\" class=\"attachment-large size-large\" alt=\"Bel\u00fcftungsanlage f\u00fcr Bunker &amp; Schutzr\u00e4ume\" srcset=\"https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-1200x800.jpg 1200w, https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-600x400.jpg 600w, https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-768x512.jpg 768w, https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-1536x1024.jpg 1536w, https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-2048x1365.jpg 2048w, https:\/\/www.bunker-bssd.de\/wp-content\/uploads\/2026\/11\/4467-510x340.jpg 510w\" sizes=\"auto, (max-width: 1020px) 100vw, 1020px\" \/>\t\t\t\t\t\t\n\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\n<style>\n#image_691818510 {\n  width: 100%;\n}\n<\/style>\n\t<\/div>\n\t\n<p><span data-contrast=\"none\"><b>In brief: <span data-contrast=\"none\"><span data-contrast=\"none\"><b><\/b>A shelter ventilation system draws in outside air, cleans it through several filter stages and pushes it into the room at a slight positive pressure. This positive pressure keeps contaminated air out, even if a joint is not perfectly airtight.<\/span><\/span><\/b> <span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"><span data-contrast=\"none\">If the power fails, the system can continue to be operated manually.<\/span><\/span><\/span>\n<\/p>\n<h2 aria-level=\"3\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"><b>How does ventilation work in a bunker?<\/b><\/span><\/h2>\n<p><span data-contrast=\"none\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\">A sealed room uses up its own air. With every breath, oxygen levels decrease and CO2 levels rise. In an emergency, you cannot simply open a window, because the outside air may contain smoke, radioactive dust or toxic gas.<\/span><\/span><\/p>\n<p><span data-contrast=\"none\">A ventilation system solves this in four steps. A fan draws in outside air, several filters clean it, the fan blows it into the room, and the stale air escapes outside through an<\/span> <span data-contrast=\"none\"><a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/shelter-equipment\/filter-systems-and-valves\/overpressure-explosion-protection-valve-uev-esv\/\">explosion protection valve <span data-contrast=\"none\"><span data-contrast=\"none\"><a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/shelter-equipment\/filter-systems-and-valves\/overpressure-explosion-protection-valve-uev-esv\/\"><\/a>with positive-pressure relief.<\/span><\/span><\/a><\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h2 aria-level=\"3\"><b><span data-contrast=\"none\">What filters are used in an NBC filter system?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"> <\/span><\/h2>\n<p><span data-contrast=\"none\">NBC stands for<\/span> <span data-contrast=\"none\"><b>nuclear, biological and chemical<\/b><\/span>. <span data-contrast=\"none\">The system filters the air in stages. A pre-filter traps coarse dust, for example in the<\/span> <a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/shelter-equipment\/filter-systems-and-valves\/overpressure-explosion-protection-valve\/\"><span data-contrast=\"none\">explosion protection valve with pre-filter.<\/span><\/a> <span data-contrast=\"none\">A particulate filter then captures fine particles, including radioactive dust and pathogens. An activated carbon filter binds toxic gases.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h2 aria-level=\"3\"><b><span data-contrast=\"none\">Why is positive pressure so important?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"> <\/span><\/h2>\n<p><span data-contrast=\"none\">The system supplies slightly more air to the room than can escape through all the gaps. As a result, air flows from the inside to the outside through every small leak, preventing contaminated outside air from entering.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<p><span data-contrast=\"none\">Common operating pressures range from at least 50 to a maximum of 250 pascals. This is a low pressure. That is why the airtightness of the enclosure, the door and every penetration is essential to maintaining it.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h2 aria-level=\"3\"><b><span data-contrast=\"none\">What happens during a power outage?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"> <\/span><\/h2>\n<p><span data-contrast=\"none\">If the power fails, people in the shelter operate the fan manually. This requires physical effort and should be shared among several people over an extended period. The system continues supplying air to the room until power is restored.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<p><span data-contrast=\"none\">For longer periods, it is also worth having an independent power source. BSSD offers portable EcoFlow<\/span> <a href=\"https:\/\/www.bunker-bssd.de\/en\/produkte\/accessories\/electrical-accessories\/\"><span data-contrast=\"none\">power stations <span data-contrast=\"none\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\">for this purpose.<\/span><\/span><\/span><\/a><\/p>\n<h2 aria-level=\"3\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"><span data-contrast=\"none\"><b>What size system do you need?<\/b><\/span><\/span><\/h2>\n<p>The size depends on the number of places in the shelter. Conventional systems are available in three sizes: the VA 40 for up to 13 people, the VA 75 for up to 25 people and the VA 150 for up to 50 people.<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"><\/span><\/p>\n<p><span data-contrast=\"none\">The order matters: determine the number of people first, then choose the system. A system designed for 13 people cannot supply 20.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h2 aria-level=\"3\"><b><span data-contrast=\"none\">How often does the filter need to be replaced?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"> <\/span><\/h2>\n<p><span data-contrast=\"none\">In peacetime, meaning while the system is not in use, the gas filter has a shelf life of 30 years. <\/span>The <span data-contrast=\"none\"><a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/shelter-equipment\/filter-systems-and-valves\/filter-replacement-for-va-75-and-va-150\/\">coarse <\/a><span data-contrast=\"none\"><span data-contrast=\"none\"><span data-contrast=\"none\"><span data-contrast=\"none\">filter<\/span> <span data-contrast=\"none\"><span data-contrast=\"none\"><span data-contrast=\"none\"><span data-contrast=\"none\"><span data-contrast=\"none\"><\/span><\/span><\/span>is compatible with the VA 40, VA 75 and VA 150, costs from \u20ac220 and can be installed yourself.<\/span><\/span><\/span><\/span><\/span><\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h2 aria-level=\"3\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"><span data-contrast=\"none\"><b>Can you build a shelter ventilation system yourself?<\/b><\/span><\/span><\/h2>\n<p><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"><span data-contrast=\"none\">Technically, it is possible to connect a fan to a filter. However, this does not guarantee reliable protection. The result depends on every stage having been tested and verified: filter performance, airtight connections, positive pressure and emergency operation. With a DIY system, no one can guarantee these values, and you will no longer be able to check them when an emergency occurs.<\/span><\/span><\/p>\n<h2 aria-level=\"3\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"><span data-contrast=\"none\"><b>What components are part of the system?<\/b><\/span><\/span><\/h2>\n<p><span data-contrast=\"none\">A filter system only works in combination with the rest of the shelter. This includes valves, such as <a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/shelter-equipment\/filter-systems-and-valves\/explosion-protection-valve\/\"><span data-contrast=\"none\"><span data-contrast=\"none\"><span data-contrast=\"none\">the explosion protection valve<\/span><\/span><\/span><\/a>, <span data-contrast=\"none\">and an airtight<\/span> <a href=\"https:\/\/www.bunker-bssd.de\/en\/produkte\/shelter-equipment\/doors-and-escape-routes\/\"><span data-contrast=\"none\">shelter door<\/span><\/a>. <a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/shelter-equipment\/filter-systems-and-valves\/air-heater-shelter-heating\/\">An air heater<\/a> <span data-contrast=\"none\"><span data-contrast=\"none\">is also available for the VA 75 and VA 150.<\/span><\/span><\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<p><span data-contrast=\"none\">If you want to control everything from one place, you can use the<\/span> <span data-contrast=\"none\"><a href=\"https:\/\/www.bunker-bssd.de\/en\/shop\/accessories\/electrical-accessories\/intelligent-building-control-system\/\">intelligent building control system<\/a><\/span>. <span data-contrast=\"none\">It controls the NBC filter system, lighting and sensors via tablet, smartphone or PC, optionally with an LTE emergency connection.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h2 aria-level=\"3\"><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"><span data-contrast=\"none\"><b>What should you check before buying?<\/b><\/span><\/span><\/h2>\n<ul>\n<li aria-setsize=\"-1\" data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559683&quot;:0,&quot;335559684&quot;:-2,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" data-aria-posinset=\"1\" data-aria-level=\"1\">Is the system designed for the number of people you need to accommodate?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:0}\"><\/span>\n<\/li>\n<ul>\n<li aria-setsize=\"-1\" data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559683&quot;:0,&quot;335559684&quot;:-2,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" data-aria-posinset=\"2\" data-aria-level=\"1\">Does it continue operating during a power outage?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\"><\/span>\n<\/li>\n<\/ul>\n<\/ul>\n<ul>\n<li aria-setsize=\"-1\" data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559683&quot;:0,&quot;335559684&quot;:-2,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" data-aria-posinset=\"3\" data-aria-level=\"1\">Have the filters and the system been type-tested?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\"><\/span>\n<\/li>\n<ul>\n<li aria-setsize=\"-1\" data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559683&quot;:0,&quot;335559684&quot;:-2,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" data-aria-posinset=\"4\" data-aria-level=\"1\">Are the door, valves and penetrations compatible with the system?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:0}\"><\/span>\n<\/li>\n<ul>\n<li aria-setsize=\"-1\" data-leveltext=\"\uf0b7\" data-font=\"Symbol\" data-listid=\"1\" data-list-defn-props=\"{&quot;335552541&quot;:1,&quot;335559683&quot;:0,&quot;335559684&quot;:-2,&quot;335559685&quot;:720,&quot;335559991&quot;:360,&quot;469769226&quot;:&quot;Symbol&quot;,&quot;469769242&quot;:[8226],&quot;469777803&quot;:&quot;left&quot;,&quot;469777804&quot;:&quot;\uf0b7&quot;,&quot;469777815&quot;:&quot;hybridMultilevel&quot;}\" data-aria-posinset=\"5\" data-aria-level=\"1\">How long does the filter last, and how do you replace it?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:0,&quot;335559739&quot;:240}\"><\/span>\n<\/li>\n<\/ul>\n<\/ul>\n<\/ul>\n<h2 aria-level=\"3\"><b><span data-contrast=\"none\">Frequently Asked Questions About Bunker Ventilation<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"> <\/span><\/h2>\n<h3><b><span data-contrast=\"none\">How much does a bunker ventilation system cost?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/h3>\n<p><span data-contrast=\"none\">At BSSD, a bunker ventilation system starts at \u20ac5,990 (VA 40). An individual gas filter (GF-40) is available from \u20ac3,189.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h3><b><span data-contrast=\"none\">What filter system does a shelter need?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/h3>\n<p><span data-contrast=\"none\">Specialised NBC filter systems are used to protect against certain chemical, biological and radioactive hazards. The appropriate system depends, among other things, on the room size, intended use and required level of protection.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h3>How does a gas filter system work in a bunker?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"><\/span><br \/>\n<\/h3>\n<p>A gas filter system cleans the incoming outside air of certain contaminants. In a suitable shelter system, the filtered air is directed into the room. Controlled positive pressure can also help prevent unfiltered air from entering through leaks.<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"><\/span>\n<\/p>\n<h3>How long does an NBC filter for a bunker last?<span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"><\/span><\/h3>\n<p>The service life of an NBC filter depends, among other things, on the type and concentration of contaminants, the air volume and the operating conditions. In peacetime, an unopened filter has a shelf life of 30 years.<\/p>\n<h3>Can a shelter ventilation system be installed retrospectively?<\/h3>\n<p>Yes. Under certain conditions, a shelter ventilation system can be retrofitted in an existing basement or shelter. Important factors include the airtightness of the room, the possibility of supplying outside air and the structural conditions.<\/p>\n<h3><b><span data-contrast=\"none\">Can you build a shelter ventilation system yourself?<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/h3>\n<p><span data-contrast=\"none\">A basic ventilation system is not equivalent to a tested shelter ventilation system. To protect against hazardous substances, the filters, airflow, airtightness and, where necessary, positive-pressure maintenance must be coordinated. A self-built solution does not automatically provide comparable protection.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<h3 aria-level=\"3\"><b><span data-contrast=\"none\">Buy a Bunker Filter System<\/span><\/b><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;134245418&quot;:true,&quot;134245529&quot;:true,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:280,&quot;335559739&quot;:80}\"> <\/span><\/h3>\n<p><span data-contrast=\"none\">Are you looking for bunker ventilation or an NBC filter system for your shelter? Discover the suitable filter systems and components from BSSD.<\/span><span data-ccp-props=\"{&quot;134233117&quot;:false,&quot;134233118&quot;:false,&quot;335551550&quot;:0,&quot;335551620&quot;:0,&quot;335559738&quot;:240,&quot;335559739&quot;:240}\"> <\/span><\/p>\n<p><a href=\"https:\/\/www.bunker-bssd.de\/en\/produkte\/shelter-equipment\/filter-systems-and-valves\/?srsltid=AYCX9vKz9AJBhoi9KLq-T5rycNmtd7KBuYULP8EPuSQrz_EvH0UB9e8A\"><b><span data-contrast=\"none\">Discover filter systems now. <\/span><\/b><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In brief: A shelter ventilation system draws in outside air, cleans it through several filter stages and pushes it into the room at a slight positive pressure. This positive pressure keeps contaminated air out, even if a joint is not perfectly airtight. If the power fails, the system can continue to be operated manually. How [&#8230;]\n","protected":false},"author":849,"featured_media":9195,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[532],"tags":[],"class_list":["post-9210","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-knowledge"],"_links":{"self":[{"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/posts\/9210","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/users\/849"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/comments?post=9210"}],"version-history":[{"count":1,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/posts\/9210\/revisions"}],"predecessor-version":[{"id":9211,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/posts\/9210\/revisions\/9211"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/media\/9195"}],"wp:attachment":[{"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/media?parent=9210"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/categories?post=9210"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bunker-bssd.de\/en\/wp-json\/wp\/v2\/tags?post=9210"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}