Sprinkler flow, number of heads and water tank calculator
Enter the hazard group and floor area to get design flow, head pressure, tank volume, pump power and a material list per TCVN 7336:2021.
Group 2, 1,500 m² floor: about 14.4 L/s (52 m³/h), sprinkler tank 52 m³ for 60 min, pump about 8.5 kW at 39 m head, and 125 K80 heads.
Preliminary results
| Step | Result | Basis |
|---|---|---|
| Density q, design area F, duration tq = 0.12 L/s·m²; F = 120 m²; t = 60 min; S = 12 m² ⚠ | TCVN 7336:2021 ⚠ | |
| Required flowQ = q·F = 0.12 × 120 | 14.40 L/s | TCVN 7336:2021 |
| Heads operating simultaneouslyn = ⌈F/S⌉ = ⌈120/12⌉ | 10 heads | TCVN 7336:2021 |
| Flow per headq₁ = q·S·60 = 0.12 × 12 × 60 | 86.4 L/min | q = K√P |
| Head pressureP = max((q₁/K)², Pmin) = max((86.4/80)², 0.50) | 1.17 bar | Q = K√P · TCVN 7336 ⚠ |
| Design flowQ = max(n·K·√P/60, q·F) | 14.40 L/s = 51.8 m³/h | TCVN 7336:2021 |
| Water volumeW = Q·t·60/1000 | 51.8 m³ | TCVN 7336:2021 ⚠ |
| Pump headH = P·10.2 + Hhh + ΔP·10.2 | 39.2 m | Bernoulli |
| Pump shaft powerN = ρ·g·Q·H/η | 8.52 kW | N = ρgQH/η |
| Total heads for the floor⌈A/S⌉ = ⌈1,500/12⌉ | 125 heads | TCVN 7336:2021 ⚠ |
Suggested materials
Frequently asked questions
How much water does a hazard group 2 sprinkler system need?
A density of 0.12 L/s·m² over a 120 m² design area gives 14.4 L/s. A 60-minute supply needs about 52 m³. Preliminary figure per TCVN 7336:2021, excluding hose reels and external hydrants.
What pressure does a K80 sprinkler need?
Head flow Q = K×√P. A K80 head delivering 96 L/min needs P = (96/80)² = 1.44 bar at the head.
How many m² does one sprinkler cover?
Under TCVN 7336:2021, hazard groups 1–3 allow about 12 m² per head and group 4 about 9 m² per head. Check the original table and head spacing.
Can I submit these results for approval?
No. The results are preliminary for material selection and budgeting. Approval drawings must be prepared by a qualified design consultant under Decree 105/2025/ND-CP (amended by Decree 347/2026/ND-CP).