{"product_id":"backdraft-damper-150mm","title":"Backdraft Damper 150mm","description":"\u003ch2\u003eKeep the grow room sealed when the fan is off\u003c\/h2\u003e\n\u003cp\u003eThis \u003cstrong\u003ebackdraft damper\u003c\/strong\u003e fits inline into a standard round duct run and uses two spring-loaded galvanised steel blades to seal the outlet automatically whenever the fan isn't running. The moment airflow stops, the blades close under their own spring tension, stopping outside air, insects and odour finding their way back into the grow space through an idle extraction line.\u003c\/p\u003e\n\u003cp\u003eIt's a passive part — no power, no controller, nothing to set up — that simply does its job every time the fan cycles off, which makes it a cheap and permanent fix for the smell and bug-ingress problems that come from running extraction on a timer or thermostat.\u003c\/p\u003e\n\u003ch3\u003eKey Benefits\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAutomatic spring-loaded blades\u003c\/strong\u003e seal the duct when the fan stops\u003c\/li\u003e\n\u003cli\u003eStops \u003cstrong\u003eodour escaping\u003c\/strong\u003e and outside air or bugs getting in\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGalvanised steel\u003c\/strong\u003e construction for durability\u003c\/li\u003e\n\u003cli\u003eNo power or controls needed — fully passive operation\u003c\/li\u003e\n\u003cli\u003eFits standard round ducting\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv class=\"hcs-specs\"\u003e\n\u003cp\u003e\u003cstrong\u003eDuct size:\u003c\/strong\u003e 4\",5\",6\"8\",10\",12\"\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterial:\u003c\/strong\u003e Galvanised steel, spring-loaded butterfly shutter\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFitting:\u003c\/strong\u003e Female-female coupling or duct clip\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Hydro Crop Shop","offers":[{"title":"100mm","offer_id":53525166915850,"sku":null,"price":9.45,"currency_code":"GBP","in_stock":true},{"title":"125mm","offer_id":53525166948618,"sku":null,"price":10.95,"currency_code":"GBP","in_stock":true},{"title":"150mm","offer_id":53500727918858,"sku":"DUCT-HCS-BKDFT-150","price":11.95,"currency_code":"GBP","in_stock":true},{"title":"200mm","offer_id":53525166981386,"sku":null,"price":14.95,"currency_code":"GBP","in_stock":true},{"title":"250mm","offer_id":53525167014154,"sku":null,"price":17.95,"currency_code":"GBP","in_stock":true},{"title":"315mm","offer_id":53525167046922,"sku":null,"price":18.95,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0748\/7127\/5786\/files\/back-draft-damper_1024x1024_9956f4fc-64f3-43b2-8a25-83f71c81853f.png?v=1786377732","url":"https:\/\/hydrocropshop.co.uk\/products\/backdraft-damper-150mm","provider":"Hydro Crop Shop","version":"1.0","type":"link"}