{"product_id":"100mm-gravity-shutter-for-extractor-fans-white","title":"100mm Gravity Shutter for Extractor Fans - White","description":"\u003ch5\u003eDescription\u003c\/h5\u003e\n\u003cp\u003eThe Knightsbridge 100mm gravity shutter is a wall-mounted backdraught prevention fitting designed for 100mm (4-inch) round extractor fan installations. Three internal gravity-operated flaps close when the fan is off, blocking backdraught air, rain, and vermin from entering through the duct. When the fan runs, airflow pushes the flaps open, allowing extraction to proceed normally.\u003c\/p\u003e\n\u003cp\u003eDesigned for installation on external walls where 100mm round ducting terminates, the shutter fits both rigid and flexible round duct types and requires a 105mm diameter cut-out in the wall. The white polycarbonate construction withstands outdoor exposure without rust or corrosion, and the 152mm square faceplate covers the cut-out and secures to the wall with the four recessed fixing points at each corner.\u003c\/p\u003e\n\u003cp\u003eThe 38mm projection from the wall when surface-mounted includes the flap housing depth, while the 22mm recessed depth indicates how far the fitting sits into the wall when flush-mounted into a recess. The gravity-operated flaps require no manual intervention or electrical connection — they open and close purely in response to airflow direction, making them a reliable passive solution for kitchens, bathrooms, utility rooms and toilet compartments with intermittent extractor fan use.\u003c\/p\u003e\n\u003ch5\u003eSpecification\u003c\/h5\u003e\n\u003ctable class=\"spec_table\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeight\u003c\/td\u003e\n\u003ctd\u003e152 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWidth\u003c\/td\u003e\n\u003ctd\u003e152 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eProjection\u003c\/td\u003e\n\u003ctd\u003e38 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eRecessed Depth\u003c\/td\u003e\n\u003ctd\u003e22 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCut-out Diameter\u003c\/td\u003e\n\u003ctd\u003e105 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConstruction\u003c\/td\u003e\n\u003ctd\u003ePolycarbonate\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinish\u003c\/td\u003e\n\u003ctd\u003eWhite\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch5\u003eDownloads\u003c\/h5\u003e\n\u003cp\u003e\u003ca href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/products_1503949_datasheet.pdf\" target=\"_blank\"\u003eProduct Specification Sheet\u003c\/a\u003e\u003c\/p\u003e\n\u003ch5\u003eFrequently Asked\u003c\/h5\u003e\n\u003cp\u003e\u003cstrong\u003eWhat fan size is this compatible with?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe shutter is designed for 100mm (4-inch) diameter extractor fans with round ducting. It fits both rigid and flexible duct types that terminate at 100mm diameter.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow does the gravity shutter prevent backdraught?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThree internal flaps close under their own weight when the fan is off, blocking reverse airflow, rain and debris. When the fan runs, the airflow pushes the flaps open. No manual operation or electrical connection is required.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCan this be installed flush with the wall?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eYes. The 22mm recessed depth allows the shutter to sit partially into the wall when installed into a recess. Surface mounting is also possible, with a total projection of 38mm from the wall face.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhat wall cut-out size is needed?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eA 105mm diameter circular cut-out is required. The 152mm square faceplate then covers this opening and fixes to the wall at the four corner points.\u003c\/p\u003e","brand":"Knightsbridge","offers":[{"title":"Default Title","offer_id":45293804093707,"sku":"EX007W","price":3.99,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/8993\/3835\/files\/107484_359d7eb4-f8cc-4729-9387-66c554f59d73.jpg?v=1714664443","url":"https:\/\/niori.co.uk\/products\/100mm-gravity-shutter-for-extractor-fans-white","provider":"Niori","version":"1.0","type":"link"}