Aspirating smoke detection
Air-sampling detection that draws the room to the detector through a pipe network — for high ceilings, high airflow, and anywhere a point detector reacts too late.
- Scope
- Survey → commissioning → AMC
- Practice
- IS 2189 · NBC 2016 Pt.4
- Typical use
- Data halls, atria, warehouses
It samples the air instead of waiting for smoke to arrive
A ceiling detector waits for smoke to reach it. In a data hall the air handling dilutes and diverts that smoke; in a warehouse or an atrium the ceiling is thirty metres above the fire; in a cold store the smoke never rises at all. An aspirating system solves this by reversing the arrangement — a fan continuously draws air from sampling points through a pipe network to one very sensitive detector.
Because it is sampling rather than waiting, and because the detector is far more sensitive than a point head, it reports at the stage where a cable is overheating rather than where a rack is alight. Multiple alarm thresholds are the point of that sensitivity: an early warning to investigate, then a pre-alarm, then fire — so somebody looks at a hot power supply long before anything triggers a suppression discharge.
The pipe network is the design. Sampling point spacing, pipe lengths and hole sizes are calculated so that transport time from the furthest point stays within limits and every point draws its share, and the pipe is routed to sample where the air actually goes — above the ceiling, under the floor, in the return air path of the CRAC units. We calculate the network, install and commission it with a smoke test from the furthest sampling point, and set the thresholds against the room rather than leaving them at factory default.
What the installation is built from
A detector, an aspirator and a calculated pipe network — plus the thresholds, which are what make it useful rather than noisy.
Tell us about the project
Send the drawings or the BOQ and we will price it line by line. Most enquiries start with a site visit, because the site decides the system — not the catalogue.