ℹ️ About This Calculator
Sprinkler system layout determines the number, spacing, and arrangement of sprinkler heads to achieve complete coverage of the protected area. Correct spacing ensures each head covers its design area at the required density. This calculator determines head spacing and count based on hazard classification, ceiling height, and room geometry per NBC 2016 Part 4 and IS 15105.
IS 15105 (Design and Installation of Fixed Automatic Sprinkler Fire Extinguishing Systems) and NBC 2016 Part 4 are the primary standards for sprinkler systems in India. Hazard classes: Light Hazard (LH) – hotels, offices, hospitals, schools; Ordinary Hazard (OH1/OH2) – manufacturing, warehouses; High Hazard (HH) – flammable liquid storage, paint shops. Sprinkler heads must be within 150 mm of ceiling; sidewall sprinklers used near walls/obstructions. TAC (Tariff Advisory Committee) approval required for insured buildings.
📐 Sprinkler Layout Calculations
❓ Frequently Asked Questions
What is the maximum sprinkler head spacing allowed?
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Per IS 15105: Light Hazard – max 4.6 m between heads, max coverage 21 m²; Ordinary Hazard – max 4.0 m (open head), 3.75 m (closed head), coverage 12–14 m²; High Hazard – max 3.0 m, coverage 9 m². Distance from wall to first head: half the maximum spacing (e.g., 2.3 m for LH). These limits ensure full coverage with spray overlap.
What is the difference between closed and open head sprinkler systems?
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Closed head (wet/dry): Each head activates individually when its fusible element or glass bulb melts at the fire. Only heads in the fire area operate – minimising water damage. Wet pipe (always water-filled) and dry pipe (air/nitrogen-filled for freezing environments) are the two types. Open head (deluge): All heads in a zone operate simultaneously when system triggers. Used for high-hazard areas, aircraft hangars, stage areas.
Does every building in India require a sprinkler system?
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NBC 2016 mandates sprinklers for: all buildings above 15 m (5 storeys); basements over 200 m²; storage buildings over 500 m²; assembly occupancies over 1000 m²; educational over 1500 m²; high-rise buildings (above 30 m – mandatory full building coverage); special hazard areas (fuel stores, paint shops) regardless of building height. Many fire insurance providers (TAC) also require sprinklers for insured buildings.
What is a concealed sprinkler and when is it used?
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Concealed sprinklers have a decorative cover plate that pops off when the ambient temperature rises. The head is recessed into the ceiling, making it invisible in normal conditions. Used in hotels, hospitals, and high-end offices for aesthetic reasons. They are slightly slower to activate than conventional pendent heads (cover plate must detach first). Same coverage and spacing rules apply.
How do I determine the hazard class for my building?
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Light Hazard (LH): hotels, offices, schools, hospitals, residential. Ordinary Hazard Group 1 (OH1): car parks, light industrial, paper mills (low-intensity). Ordinary Hazard Group 2 (OH2): chemical works, textile mills, wood working. High Hazard (HH): flammable liquid storage, aircraft hangars, paint manufacturing. When in doubt, use the higher (more conservative) classification. TAC guidelines also provide occupancy-specific classifications.
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