System Sensor DST5 InnovairFlex Sampling Tube
Overview
The DST5 is a patented sampling tube designed to extend smoke detection capability across HVAC ductwork in commercial fire alarm systems. This 4-to-8-foot tube connects to a System Sensor InnovairFlex D4120 duct smoke detector head, allowing aspiration-based detection across long duct runs where a single detector cannot cover the required distance. The tube operates at 29VDC and installs from front or back of the detector housing with no tools required — a key advantage when access is tight or when reconfiguring detection zones without breaking wiring.
Compatibility
The DST5 pairs exclusively with System Sensor InnovairFlex D4120 4-wire photoelectric duct detectors. It is designed for rectangular or square ductwork installations where air velocity ranges from 100 to 4,000 feet per minute. The detector head itself supports temperatures from –4°F to 158°F and humidity from 0 to 95 percent (non-condensing), so the tube operates within those same environmental bounds. The D4120 power board can monitor up to two sensors simultaneously (supply and return side), and as many as 50 InnovairFlex detectors can be interconnected in a single network.
Installation Notes
The sampling tube installs without tools — the patented quick-connect design snaps into the front or back of the D4120 detector housing. The D4120 housing provides a ¾-inch conduit knockout for field wiring entries and built-in short-circuit protection to safeguard the power board during installation. High-contrast terminal designations on the power board simplify wiring. Air velocity and ductwork dimensions must stay within the D4120's rated 100–4,000 fpm range to avoid nuisance alarms or missed detections; verify HVAC blower CFM before selecting tube length.
