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EN 12845 · OH1 (Ordinary Hazard Group 1)

Hotel fire sprinkler design

Guest rooms, corridors and back-of-house in hotels are classified OH1 under EN 12845. NFPA 13 maps the same occupancy to Light Hazard with quick-response heads.

Design parameters

StandardEN 12845
Hazard classOH1 (Ordinary Hazard Group 1)
Design density5.0 mm/min
Area of operation72 m² (wet)

Design notes

  • Concealed pendent heads in guest rooms for aesthetics
  • Sidewall heads above bed lines where ceiling penetration is limited
  • Risers in service shafts with floor-level isolation valves
  • Coordinate with smoke control / pressurisation system

Typical equipment

  • QR pendent K80 sprinklers
  • Recessed concealed heads
  • DN100 wet alarm valve
  • Single electric pump

How FireTwin AI handles hotel projects

Upload your floor plan or model the building footprint directly. FireTwin AI classifies rooms, applies the EN 12845 OH1 (Ordinary Hazard Group 1) grid, runs the hydraulic calculation from the most remote area back to the pump, and produces a priced BOM — all re-verified on every edit.

Design it in FireTwin AI

Generate a compliant sprinkler layout, run the hydraulic calculation and export a priced bill of materials — checked against EN 12845 and NFPA 13.

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