EN 12845
CMDA vs CMSA vs ESFR — Three-Mode Comparison
CMDA classical control, CMSA large droplet, ESFR suppression: a decision matrix comparing K-factor, pressure and water demand across the three modes.
EN 12845
CMSA — Control Mode Specific Application Sprinklers
CMSA (Control Mode Specific Application) sprinklers: the former large drop head, K-factors, commodity-to-design matching, differences from ESFR and...
EN 12845
CMSA Design Criteria in Detail
CMSA design criteria: K-factor, pressure, number of design sprinklers, commodity-to-listing matching and in-rack coordination in detail.
EN 12845
EN 12845 Alternate (Seasonal) Installations
EN 12845 alternate installations: the summer wet and winter dry cycle, the changeover procedure, the 25% enlarged design area and the field errors...
EN 12845
EN 12845 Annex A: Typical Occupancy Hazard Classification
The EN 12845 occupancy classification annex: schools, hospitals, hotels, factories and warehouses across LH, OH1-4 and HHP1-4, and how to classify...
EN 12845
EN 12845 Annex C: Alphabetical Commodity Categories
The EN 12845 alphabetical commodity list: category mapping for 21 common products, plastic container exceptions and the link to the material factor...
EN 12845
EN 12845 Annex D — Installation Zoning Rules
EN 12845 Annex D zoning: maximum zone area, zone valve location, flow alarms, multi-storey zone distribution and correct zone planning on site.
EN 12845
EN 12845 Annex E — High-Rise Requirements
EN 12845 Annex E high-rise sprinklers: the 45 m threshold, OH3 design, subdivision into installations of not more than 45 m, valve standing pressures, the 12 bar exception and one superior single water supply.
EN 12845
EN 12845 Annex F — Additional Reliability Measures
EN 12845 Annex F system reliability: 2 400 m² zones for LH/OH, wet pipe installations, quick response sprinklers, full operation during alarm valve servicing, one superior single water supply and theatre measures.
EN 12845
EN 12845 Annex G — Aerosol Product Storage
EN 12845 Annex G aerosol storage: the cage requirement, the alcohol and hydrocarbon based rows of Table G.1 (12.5 mm/min over 260 m² and 25.0 mm/min over 300 m²) and quick response in-rack sprinklers.
EN 12845
EN 12845 Annex G — Flammable Liquid Storage
EN 12845 Annex G flammable liquid storage: four classes by flash and boiling point, metal drums by orientation and tier, and the Tables G.2-G.4 design rules (7.5-25 mm/min over 450 m²).
EN 12845
EN 12845 Annex G — Hanging Garment Storage
EN 12845 Annex G hanging garment storage: product configuration, hang height, in-rack protection and design density rules.
EN 12845
EN 12845 Annex G — Idle Pallet Storage
EN 12845 Annex G idle timber and plastic pallet storage: stack heights, indoor and outdoor separation, sprinkler design density and distance rules.
EN 12845
EN 12845 Annex G — Nonwoven Synthetic Fabric Storage
EN 12845 Annex G storage of nonwoven synthetic fabric: the Table G.7 height ladder (10.0-30.0 mm/min over 260/300 m²), Category IV in-rack protection with 12.5 mm/min over 260 m² at the ceiling, and the Annex L note above 4.1 m.
EN 12845
EN 12845 Annex G — PP/PE Storage Bins
EN 12845 Annex G PP/PE storage bins: HHS Category IV, 1.5 m / 2 m in-rack spacing on ST4, the 3 m storage limit with non-inflammable (e.g. steel) pallets, and the mandatory film forming foam additive.
EN 12845
EN 12845 Annex G — Wooden Cask Spirit Storage
EN 12845 Annex G storage of spirit based liquors (over 20% alcohol) in wooden barrels: the 4.6 m ceiling-only limit, 15 mm/min over 360 m², in-rack sprinklers above 4.6 m and recommended drainage or bunding.
EN 12845
EN 12845 Annex H — System Monitoring
EN 12845 Annex H system monitoring: supervised valves, pressure, water level, pump controller signals, alarm panels and continuous supervision prin...
EN 12845
EN 12845 Annex I — Alarm Transmission Levels
EN 12845 Annex I alarm transmission levels: only two alarm levels (A fire, B fault), the Table I.1 assignments and transmission to a permanently attended location.
EN 12845
EN 12845 Annex J — Impairment Procedures
EN 12845 Annex J impairment management: planned and unplanned outages, tagging, fire watches, insurer notification and the restoration procedure.
EN 12845
EN 12845 Annex K — 25-Year Sprinkler Inspection
EN 12845 Annex K 25-year sprinkler sampling test: sample numbers, laboratory testing, K-factor verification, RTI measurement and service life asses...
EN 12845
EN 12845 Annex Q — Periodic System Inspection
EN 12845 periodic inspection and Annex Q: the qualified person, the at least yearly inspection, the recommended independent body, the report scope and the list of deviations.
EN 12845
EN 12845 Annual, Three-Year and Ten-Year Routines
EN 12845 annual pump flow test, diesel failed-to-start, float valve and suction strainer; three-yearly tank and valve overhaul; ten-yearly tank cle...
EN 12845
EN 12845 Area of Operation: Shape and Location
EN 12845 area of operation shape: the 1.2 x root A rectangle rule, selecting the hydraulically most remote sprinkler group, and solving the narrow...
EN 12845
EN 12845 Beams, Ceilings and Sprinkler Layout
EN 12845 structural obstruction rules: deflector geometry under beams, the every-third-bay rule for narrow bays, roof truss flange clearances and s...
EN 12845
EN 12845 Block Plan, Signage and Marking Rules
EN 12845 block plan sign content, sprinkler valve marking, zone maps, fire service signs, spare sprinkler cabinets and correct signage on site.
EN 12845
EN 12845 Ceiling Sprinklers: Flush, Recessed and Concealed
EN 12845 pendent, flush, recessed and concealed sprinklers: where each is prohibited, deflector position, K-factor limits, cover plate temperature...
EN 12845
EN 12845 Commissioning, Hydrostatic Testing and Certification
EN 12845 Clause 19 commissioning: hydrostatic testing (15 bar or 1.5x working), flushing, alarm tests, the commissioning certificate and handover f...
EN 12845
EN 12845 Commodity Classification: Material Factors M1 to M4
EN 12845 commodity classification: material factors M1 to M4, the configuration table, categories I to IV and how the result drives sprinkler desig...
EN 12845
EN 12845 Concealed Space Pipework and Sprinklers
EN 12845 sprinkler requirements in concealed spaces above ceilings, below raised floors and in roof voids: material class, airflow risk and testing...
EN 12845
EN 12845 Control Valve Set, Stop Valves and Alarm Valve Arrangement
The EN 12845 control valve set: OS&Y and monitored butterfly stop valves, wet, dry, alternate and pre-action alarm valves, drain and test conne...
EN 12845
EN 12845 Design Density and Area of Operation
EN 12845 design density (mm/min) and area of operation: reading the density-area tables, the 25% dry system increase and the basis of the hydraulic...
EN 12845
EN 12845 Diesel Engine Pump Sets
EN 12845 diesel pump sets: A2:2026 Clause 10.9 refers the pump set to EN 17451 and keeps only fresh air, the four starter alarm indications and the site commissioning test; the 15 s rule now applies only to electric pump sets.
EN 12845
EN 12845 Diesel Pump Batteries, Chargers and Starters
EN 12845 diesel fire pump starting: A2:2026 Clause 10.9 leaves batteries, chargers and start attempts to EN 17451; what remains are the four alarm indications, Annex I transmission and the monthly battery check.
EN 12845
EN 12845 Diesel Pump Weekly Exercise Test
The EN 12845 weekly diesel pump routine: 20 minute run, automatic start and manual restart, fuel, oil and coolant checks, log book content and c...
EN 12845
EN 12845 Drain, Test and Flushing Valves
EN 12845 drain valves, alarm and remote test valves, flushing connections with the Table 39 drain sizes and the weekly, quarterly and annual routines that use these valves.
EN 12845
EN 12845 Dry Pipe Installations
EN 12845 dry pipe sprinkler installations: air charging, water transit time (60/90 s), use in freezing areas, the 25% design area increase and comp...
EN 12845
EN 12845 Electric Sprinkler Pump Sets
EN 12845 electric pump sets: the dedicated supply, the 15 second rule, cabling and labelling rules, pump monitoring, and the protection provisions deleted in A2:2026.
EN 12845
EN 12845 Electrical Flow and Pressure Switches
EN 12845 electrical monitoring: flow and pressure switches, tamper switches, low level and temperature supervision, type A and B alarms and fire pa...
EN 12845
EN 12845 Fire Service and Monitoring Centre Alarm Connection
EN 12845 alarm transmission: alarm levels A and B, Table I.1, the Clause 16.3 fire service connection, Annex H monitoring thresholds and alarm test intervals.
EN 12845
EN 12845 Fitting and Valve Pressure Losses
The EN 12845 equivalent length method: fitting and valve values, alarm valve and backflow additions, a worked example and the tee-counting error.
EN 12845
EN 12845 Frost Protection Strategies
EN 12845 freeze protection: dry systems, alternate wet and dry, glycol antifreeze, heat tracing and sprinkler design in freeze-prone areas.
EN 12845
EN 12845 HHP High Hazard Process Design
EN 12845 HHP classes: paint, plastic injection, rubber and timber processing. 7.5/10.0/12.5 mm/min over 260 m2, K115 selection, the HHP4 deluge exc...
EN 12845
EN 12845 HHS High Hazard Storage Design
EN 12845 high hazard storage: ST1-ST6 configurations, Category I-IV commodities, design density by height band and the 260-300 m2 area of operation.
EN 12845
EN 12845 Hazard Classes: LH, OH1 to OH4, HHP and HHS
EN 12845 hazard classification: LH, OH1 to OH4, HHP1 to HHP4 and HHS1 to HHS4, with design densities and the occupancy examples of Annex A.
EN 12845
EN 12845 In-Rack Sprinkler Layout by ST1-ST6
EN 12845 in-rack sprinkler layout across ST1-ST6 rack configurations: flue spacing, vertical intervals, K-factor, water shields and hydraulic desig...
EN 12845
EN 12845 Intermediate Level Sprinklers in High Hazard
EN 12845 intermediate level sprinklers in high hazard occupancies: triggers, vertical and horizontal spacing, water shields and the combined hydrau...
EN 12845
EN 12845 Light Hazard (LH) Design
EN 12845 light hazard: 2.25 mm/min density over 84 m2, K57 sprinklers and no dry or alternate installation (OH1 is used instead). Pre-calculated design and a worked pipe friction example.
EN 12845
EN 12845 Maximum Sprinkler Coverage Area
EN 12845 coverage limits: LH 21 m2, OH 12 m2, HHP/HHS 9 m2, the separate sidewall table, reductions under obstructions and a worked example.
EN 12845
EN 12845 Maximum Water Pressure and Service Connections
EN 12845 water supply limits: the 12 bar ceiling on sprinkler equipment, town main service connection rules, backflow prevention and high-rise zoning.
EN 12845
EN 12845 Minimum Distance Between Sprinklers
Why sprinklers closer than 2 m fail to operate: cold soldering, deflector-to-ceiling distance, and the rules for approaching walls, beams and canop...
EN 12845
EN 12845 Minimum Pipe Diameters
EN 12845 minimum DN values for fully calculated systems, the pre-calculated range and distribution sizes, and how steel grade and galvanising chang...
EN 12845
EN 12845 Minimum Sprinkler Discharge Pressure
EN 12845 minimum sprinkler discharge pressure: LH 0.7 bar, OH 0.35 bar, HHP/HHS 0.5 bar, absolute versus average minimum, in-rack 1.0 bar (K115) and 2.0 bar (K80).
EN 12845
EN 12845 Monthly Routine — Battery Checks
The EN 12845 monthly routine: diesel pump starter batteries, control panel cells, electrolyte specific gravity, replacement decisions and charger c...
EN 12845
EN 12845 Ordinary Hazard (OH1-OH4) Design
EN 12845 OH1 to OH4: the 5.0 mm/min density, 72-360 m2 areas of operation, the 25% dry system increase and the 0.35 bar OH minimum and the 0.56 bar a K80 sprinkler needs for 5.0 mm/min over 12 m².
EN 12845
EN 12845 Pipe Friction Loss: Hazen-Williams
The EN 12845 Hazen-Williams formula, C coefficients by material (mild steel 120, stainless 140, copper 140) and a DN50 worked example.
EN 12845
EN 12845 Pipe Joining: Steel Welding, Flexible Connectors and Copper
EN 12845 pipe joining: steel welding to EN ISO 9606-1, grooved and threaded joints, flexible connectors, copper pipe and what the C=120/140 differe...
EN 12845
EN 12845 Pipe Supports and Hanger Spacing
EN 12845 pipe support rules: 4 m for steel and 2 m for copper, the 50 percent exception, grooved joint rules, hanger load tables and the seismic gap.
EN 12845
EN 12845 Pre-Action Installations: Type A and Type B
EN 12845 pre-action installations: Type A (opened by detection only), Type B (opened by detection or by sprinkler operation), EN 54 detection and installation size limits.
EN 12845
EN 12845 Pre-Calculated Design for HHP and HHS
EN 12845 pre-calculated sizing for high hazard: K-factor limits, sprinkler count restrictions, the range and distribution tables, and the move to f...
EN 12845
EN 12845 Pre-Calculated LH Design
EN 12845 pre-calculated light hazard design: K57 sprinklers, the four-sprinkler rule, range pipe sizes, the 225 L/min pump duty and the most common...
EN 12845
EN 12845 Pre-Calculated OH Design
EN 12845 pre-calculated design for OH1-OH4: range and distribution pipe sizes, K80 sprinklers, the 0.35 bar minimum, wet versus dry, and pump flow.
EN 12845
EN 12845 Pre-Calculated versus Fully Calculated Design
The difference between the EN 12845 pre-calculated table method and fully calculated hydraulic design, when to choose each, and the field practice...
EN 12845
EN 12845 Pressure Tanks
EN 12845 pressure tanks: limited to LH and OH1, the air-to-water ratio, the tank pressure formula, pressure equipment maintenance and why modern pr...
EN 12845
EN 12845 Pump Controllers and Monitoring
EN 12845 pump controllers: automatic start from two pressure switches, the manual-only stop rule, the mandatory alarm signals and BMS integration.
EN 12845
EN 12845 Pump Performance Characteristics
The EN 12845 pump pressure-flow curve: Table 16 nominal and characteristic points, the Table 14 nominal flow, Figure 7 for calculated systems, closed valve pressure and the 12 bar limit, with field practice.
EN 12845
EN 12845 Pump Room Requirements: Ventilation, Drainage, Lighting
EN 12845 pump room requirements: the 60 min fire-resistant compartment and its order of preference, 4 C / 10 C minimum temperatures, sprinkler protection of the room, the single ventilation sentence, and why drainage, lighting and clearances lie outside the standard.
EN 12845
EN 12845 Pump Suction Conditions and Pump Room Layout
EN 12845 suction and pump room rules: positive suction head, the NPSHa-NPSHr margin, the 60 min fire-resistant compartment, 4 C (electric) / 10 C (diesel) minimum room temperatures and fi...
EN 12845
EN 12845 Quarterly and Half-Yearly Routines
EN 12845 quarterly (13 week) and half-yearly maintenance: hazard review, sprinkler cleaning, coatings, water supply testing, dry valve exercising a...
EN 12845
EN 12845 Reduced Capacity Tanks
EN 12845 reduced capacity sprinkler tanks: guaranteed town main infill, automatic filling, minimum effective volumes and the field errors that follow.
EN 12845
EN 12845 Sidewall Sprinklers
EN 12845 sidewall sprinkler layout: maximum coverage area, room width, number of rows, deflector position, K-factor selection and field errors.
EN 12845
EN 12845 Sprinkler Flow and K-Factor
EN 12845 K-factors: the formula Q = K root P with P in bar, K57-K160 by hazard class from Table 37a, the minimum pressures, NFPA equivalents and the K160-K480 range of EN 12845-2.
EN 12845
EN 12845 Sprinkler Guards, Water Shields, Escutcheons and Corrosion Protection
EN 12845 sprinkler accessories: guards, the 75 mm water shield, escutcheon rules and EN 12259-1 compliant corrosion coatings in field practice.
EN 12845
EN 12845 Sprinkler Pumps and Multiple Pump Arrangements
EN 12845 pump sets: single, duplex and N+1 arrangements, electric and diesel combinations, jockey pump sizing and the field errors that follow.
EN 12845
EN 12845 Sprinkler Storage Tank: Volume, Refilling and Effective Capacity
EN 12845 sprinkler tanks: effective capacity, the 36-hour refill rule, reduced capacity conditions, anti-vortex plates and suction inlet clearances.
EN 12845
EN 12845 Sprinkler Temperature Ratings and Colour Codes
EN 12845 sprinkler temperature ratings: the ambient plus 30 C rule, glass bulb and fusible link colour codes, and selection for roof voids, boiler...
EN 12845
EN 12845 Sprinkler Thermal Sensitivity and RTI Classes
EN 12845 thermal sensitivity: quick, special and standard A response classes, why the standard gives no RTI numbers, Table 38 (quick response in racks, not in dry or pre-action Type A), the ceiling-rack ranking rule and Annex F.
EN 12845
EN 12845 Storage Configurations: ST1 to ST6
The EN 12845 ST1-ST6 storage configurations: block stacking, post pallets, beam pallet racking and shelves, with the Table 2 limits, ceiling and in-rack protection, and the configurations the standard does not cover.
EN 12845
EN 12845 Subsidiary Dry and Alternate Extensions
EN 12845 subsidiary extensions: design limits for small dry or alternate branches fed from a wet system, sprinkler counts, water delivery time and...
EN 12845
EN 12845 Suction Conditions and Suction Pipework
EN 12845 suction pipework: diameter, eccentric reducers, foot valves, vortex breakers, gradient and the NPSH margin that keeps air out of the pump.
EN 12845
EN 12845 Town Main as a Water Supply
EN 12845 conditions for using the town main as a sprinkler water supply: the three-point pressure-flow test at maximum demand, water authority approval, boosted mains, other services taken from the main and the connection arrangement.
EN 12845
EN 12845 Underground and Above-Ground Pipework
EN 12845 pipework: underground and above-ground materials, corrosion resistance, welding and flexible joints, supports and hangers, and the 15 bar / 2 h hydrostatic commissioning test.
EN 12845
EN 12845 Water Flow Alarm and Water Motor Gong
EN 12845 water motor alarms: the Pelton gong, pressure switches, retard chambers and the site installation errors, with an NFPA 13 comparison.
EN 12845
EN 12845 Water Spray Subsidiary Extensions
EN 12845 subsidiary water spray extensions on a sprinkler system: deluge valves, the 80 mm connection limit, the additional water demand, why the standard gives no density, and the Annex F.7 theatre drencher.
EN 12845
EN 12845 Water Supplies: Duration, Continuity and Frost Protection
EN 12845 water supplies: 30 min for LH, 60 for OH and 90 for high hazard; single, superior single and duplicate continuity classes; and freeze prot...
EN 12845
EN 12845 Water Supply Selection: Single, Duplicate and Combined
EN 12845 single, superior single, duplicate and combined water supplies: which to choose for LH, OH, HHP and HHS, with field practice and common er...
EN 12845
EN 12845 Water Supply Test Arrangements and Test Procedure
EN 12845 water supply testing: the three-point pressure-flow curve plus static pressure, flow meter accuracy and capacity (±5 %, 140 %), the ±1.6 % test gauge and the annual test routine from field practice.
EN 12845
EN 12845 Weekly User Routine
The EN 12845 weekly routine: pressure and level checks, water motor alarm test, automatic pump start test, diesel restart, trace heating and logboo...
EN 12845
EN 12845 Wet Pipe Installations
EN 12845 wet pipe sprinkler installations: permanently water-filled pipework, no freezing risk and the 95 C upper limit (no 4 C rule in 11.1.1), the default installation type, alarm valve area limits an...
EN 12845
EN 12845 Zone Test and Drainage Facilities
EN 12845 zone test connection, alarm test valve, drainage arrangements, low-point drains, inspector test connection and correct drainage design on...
EN 12845
EN 12845-1 Annex N — The CMSA Informative Annex
EN 12845-1 Annex N: the normative referral annex for CMSA, its two subclauses, the EN 12845-2 Annex A class conversion and where the CMSA design criteria now sit.
EN 12845
EN 12845-1 Annex P — The ESFR Informative Annex
EN 12845-1 Annex P: the normative annex that makes EN 12845-2 binding for ESFR, the recommended three 50% pump sets, the Annex A class conversion and where the ESFR numbers actually are.
EN 12845
EN 12845-2 Annex O — P&ID Flow Diagram Example
EN 12845-1 Annex O: the informative single-figure P&ID example, where the standard requires a P&ID, instrument details on layout drawings and the topics the annex does not cover.
EN 12845
EN 12845-2:2024 Overview — ESFR and CMSA
The EN 12845-2:2024 European standard: ESFR and CMSA sprinkler design rules and how they relate to EN 12845-1.
EN 12845
EN 12845:2026 (+A2): What Changed and the New Part 2
EN 12845:2015+A2:2026 and EN 12845-2:2024 renew the European sprinkler standard: the A2 changes, ESFR and CMSA moved into Part 2, EN 17451 pump set...
NEW · EN 12845
Height Limits in EN 12845: Ceiling, Building, Storage, Concealed Spaces and In-Rack
Seven thresholds in one table: ESFR 16.8 m, the 9.1 m spacing rule, 12 m authority consultation, 4 m clearance, 45 m high-rise, 0.8 m concealed spaces, in-rack 3.5 / 9.1 / 12.2 m.
EN 12845
ESFR Design Criteria in Detail
ESFR design in detail: K-factor, pressure, design sprinklers, water demand, hydraulic calculation, ceiling conditions and commodity compatibility.
EN 12845
ESFR and CMSA Placement & Clearance Rules
ESFR and CMSA sprinkler placement: distance below ceiling, deflector position, sprinkler spacing and clear space above the top of storage.
EN 12845
HHS5–HHS12 High-Bay Sprinkler Design
HHS5 and the 12-sprinkler ESFR design of EN 12845-2 Clause 5.4: why there is no HHS6 or beyond, the additional requirements, water demand from the standard's values and the pump arrangement.
EN 12845
NFPA 13 vs EN 12845: A Detailed Comparison
A clause-by-clause comparison of NFPA 13 and EN 12845: units, density and area, K-factor notation, design method, water supply duration, hazard cla...
EN 12845
Non-Storage Occupancies in ESFR/CMSA Buildings
Transitions between ESFR/CMSA storage and offices, packing and shipping areas: mixed-occupancy sprinkler strategy and zone separation.
EN 12845
Obstructions to ESFR and CMSA Discharge
Obstruction rules for ESFR and CMSA: how beams, HVAC ducts, light fittings and rack supports affect the sprinkler discharge pattern.
EN 12845
Protecting Unheated Areas with ESFR and CMSA
ESFR and CMSA protection in unheated, freeze-prone warehouses: dry pipe valves, pre-action, antifreeze and cold-store sprinkler strategy.
EN 12845
Roof Slope, Skylight and Ventilation Limits
Roof slope, skylight and smoke-vent limits for ESFR and CMSA sprinkler systems, with standard values and alternative design strategies.
EN 12845
The ESFR Concept — K-Factor and Suppression
The ESFR (Early Suppression Fast Response) concept: K-factor selection (K200, K240, K360), RTI, suppression versus control, pressure and droplet ve...
EN 12845
What Is EN 12845? Scope and Differences from NFPA 13
The scope of EN 12845, its version structure from 2015 to the 2026 amendment, hazard classes and design densities, and a side-by-side comparison wi...