{"product_id":"duct-smoke-detector-photo-4wire","title":"Duct Smoke Detector 4-Wire Photoelectric Smoke Detection","description":"\u003cp\u003eSmoke introduced into an air duct system can quickly spread throughout an entire building, making early detection critical. The D4120 and D4S Duct Smoke Detectors are specifically designed for HVAC air duct applications, providing reliable smoke detection before hazardous conditions escalate. Using advanced 4-wire photoelectric sensing technology, these detectors continuously sample airflow within the duct to identify the presence of smoke at its earliest stages.\u003c\/p\u003e\u003ch3\u003eKey Features\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eDuct smoke detector designed for HVAC air duct smoke detection\u003c\/li\u003e\n\u003cli\u003e4-wire photoelectric smoke sensing technology for early detection\u003c\/li\u003e\n\u003cli\u003eEfficient housing design samples air passing through the duct\u003c\/li\u003e\n\u003cli\u003eInitiates alarm signals to support fan shutdown and system control\u003c\/li\u003e\n\u003cli\u003eDesigned to operate on 24 VDC, 24 VAC, or 120 VAC power sources\u003c\/li\u003e\n\u003cli\u003eAlarm and supervisory relay contacts for control panel integration\u003c\/li\u003e\n\u003cli\u003eAuxiliary relay provided for fan and blower shutdown\u003c\/li\u003e\n\u003cli\u003eDetector interconnection supports signaling of up to 50 detectors for coordinated fan shutdown\u003c\/li\u003e\n\u003cli\u003eNot designed for 2-wire applications\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Buildory","offers":[{"title":"Default Title","offer_id":52083117195585,"sku":"D4210","price":175.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0881\/7806\/5729\/files\/Buildory_D4210.webp?v=1786676843","url":"https:\/\/buildory.com\/products\/duct-smoke-detector-photo-4wire","provider":"Buildory.com","version":"1.0","type":"link"}