The SuperDuct four-wire smoke detector is ideally suited to HVAC applications where early indication of combustion is required within the confined space of ventilation ductwork. SuperDuct detectors and controllers feature a unique modular design that speeds installation and simplifies maintenance. Separate housings enable access to either the controller or detector without affecting the other. The detector assembly provides easy access to the smoke sensor, its wiring connections, sample and exhaust tube fittings, and the smoke chamber itself. Air enters the assembly by means of an air sampling tube, and exits by means of a six-inch exhaust tube. The controller can accommodate up to two detectors. One or both detectors may be installed remotely from the controller. A Category 5 wiring harness is used for interconnection when detectors are installed remotely from the controller.