The 14340 Smoke Emitter Provides Effective, Low Cost Leak Testing of Heat Exchangers, Air Ducts, Tanks, Boilers, and Provides Visual Air Balancing of HVAC Systems. The Cartridges Produce Clean, Oil-Free Smoke through Chemical Reaction. Can also be used for Fire Drills, as well as the Placement and Testing of Smoke Alarms and Detectors