Data centres are the backbone of the digital economy. This technical guide covers fire protection strategies, suppression technologies, and resilience requirements for UK data centre operations.. Critical Infrastructure Fire Protection Data centres house the digital infrastructure that modern society depends upon. A fire in a major data centre can disrupt banking, healthcare, communications, and government services. The fire safety approach must reflect this criticality. UK Data Centre Landscape Over 450 colocation data centres in the UK London is the largest data centre market in Europe Hyperscale facilities increasingly being built outside London Data centres classified as Critical National Infrastructure (CNI) Planning policy now supports data centre development Fire Risks in Data Centres Electrical Risks UPS systems : Battery rooms with lithium ion or lead acid batteries Transformers : High voltage equipment with oil cooling Power distribution : Busbar and cable routing creating fire paths Arc flash : High energy electrical faults causing ignition IT Equipment Risks Server hardware with continuous electrical load Cable density creating fuel load and fire paths Hot aisle/cold aisle configurations affecting fire behaviour Overhead cable trays creating concealed fire spread paths Mechanical Risks Diesel generator fuel storage and supply Cooling system refrigerants (some flammable) Raised floor and ceiling void spaces Roof mounted cooling plants Detection Strategy Very Early Warning Detection Data centres demand the earliest possible detection: VESDA (Very Early Smoke Detection Apparatus) — aspirating detection at highest sensitivity Pre action alarm at Alert level (0.03% obs/m) Action alarm at Action level (0.1% obs/m) Fire alarm at Fire 1 level (1.0% obs/m) Response escalation at each alarm level Detection Zones Above floor server hall detection Below raised floor detection Above ceiling void detection Cable riser detection UPS and battery room detection Each zone independently monitored Suppression Systems Clean Agent Gas Suppression Novec 1230 — most common clean agent for data centres FM 200 (HFC 227ea) — established clean agent (higher GWP) Inert gas (IG 541, IG 55) — zero GWP, larger cylinder storage Designed to extinguish fire without damaging IT equipment Total flooding concentration held for minimum 10 minutes Room integrity testing essential (door fan test to EN 15004) Resilience Design EN 50600 Classification Class 1 : Basic (single path, no redundancy) Class 2 : Redundant capacity components (N+1) Class 3 : Concurrently maintainable (dual paths, one active) Class 4 : Fault tolerant (dual active paths, automatic failover) Fire Safety Implications of Resilience Higher classes require independent fire protection for each path Compartmentation between redundant systems Fire in one path must not affect the other Separate suppression systems for each compartment Independent detection zones per system path Battery Energy Storage Lithium ion UPS batteries present escalating fire risks: Thermal runaway potential in lithium ion cells Off gassing of toxic and flammable gases before thermal runaway Cascade failure potential (cell to cell propagation) Water based suppression required (gas suppression insufficient for battery fires) Dedicated battery rooms with enhanced ventilation Gas detection for hydrogen fluoride and other toxic gases Business Continuity Fire strategy must align with business continuity requirements Recovery Time Objectives (RTO) drive fire protection investment Insurance requirements often exceed building regulation minimums Regular fire drills without service interruption Documented emergency operating procedures for all fire scenarios Magnus Opifex SEVEN LTD — UK's Leading Fire Safety & Fire Engineering Consultancy 🌐 magnus opifex.co.uk 📞 +44 (0) 20 3488 1926 ✉️ info@magnusopifex.co.uk Founded by Daniel Sheridan, Magnus Opifex SEVEN LTD delivers award winning fire engineering, fire risk assessments, and building safety consultancy across the United Kingdom and internationally.