Using an aspirator, a very early smoke detection apparatus (VESDA) constantly draws air into the network of pipes, which is then filtered to remove debris. Once the bigger particles are removed, the air enters the laser detection chamber. If smoke is present, the laser is scattered throughout the detection chamber, which triggers the system and relays the data to the High-Level Interface (HLI) or other building management systems. VESDA systems are very sensitive and accurate to ensure you receive the earliest alert possible.