Condensed aerosol is suppression stripped to its essentials: a compact, self-contained unit that needs no pipework, no pressurised cylinders and no agent storage room. Fixed to the enclosure it protects, it discharges a fine potassium-based aerosol that interrupts the fire at the flame itself. For switchrooms, plant rooms and battery enclosures, it’s protection without the construction project.
Condensed aerosol works differently from gas. Each unit holds a stable solid compound that, on activation, generates an ultra-fine potassium-based aerosol. The particles interrupt the chemical chain reaction of the flame itself, so a small unit delivers serious suppression without displacing oxygen from the room. Systems are designed to the BS EN 15276 series — the European standard covering condensed aerosol components, design, installation and maintenance.
Because everything lives inside the unit, there is nothing else to build. No pipework runs. No pressurised cylinder banks. No agent storage room, no major penetrations to fire-stop, no weeks of disruption. Units mount directly in or above the enclosure they protect and connect to detection by cable. For a live site, that is the difference between an afternoon’s work and a construction project.
Aerosol earns its place in the spaces a full gaseous system cannot justify: electrical switchrooms, plant rooms, generator enclosures, UPS and battery rooms, and the energy-storage enclosures now appearing across commercial estates. These are typically compact, normally unoccupied spaces where discharge visibility matters less and installation economics matter more. We assess each risk against BS EN 15276 — including occupancy, clearances and enclosure behaviour — before specifying it.
This is proven work, not a new line. Gemini installed condensed aerosol units at the Peterborough Court & Daniel House project in the City of London, alongside the IG-55 gas suppression delivered for the same building. Small units, demanding client, zero fuss — which is rather the point of aerosol. Every unit we fit is backed by our 24-hour named-engineer response.
On activation, a solid compound inside the unit converts to an ultra-fine cloud of potassium-based particles. Those particles interfere with the free radicals that keep a flame burning, breaking the combustion chain reaction directly. Unlike inert gas, it does not work by removing oxygen, which is why such a small unit can protect a meaningful volume. The BS EN 15276 series governs how units are specified, applied and maintained.
It is best suited to normally unoccupied enclosures. A discharge fills the space with a dense particulate cloud that sharply reduces visibility, and BS EN 15276 sets safety requirements around occupancy, warnings and pre-discharge delays. For switchrooms, plant rooms and battery enclosures — spaces people enter occasionally rather than work in — it is ideal. For occupied areas such as data halls, we would normally design an inert gas system instead.
Economics and disruption. For a small enclosure, a gaseous system carries fixed overheads — cylinders, pipework, venting, storage space — that can dwarf the risk being protected. Aerosol removes nearly all of that: units are compact, installation is quick and the building barely notices the work. Because Gemini designs and installs gaseous and aerosol systems alike, our recommendation follows your risk, not our stockroom.
A named engineer, not a call centre, comes back within 24 hours. Tell us the building and what you’re dealing with, and we’ll scope it properly.