🚿

Hot Water Production Sizing

Free

Size hot water tank volume and production power based on building type and occupancy.

🏢Building
dwellings

0.7 housing, 0.8 hotel, 1.0 gymnasium

🔥Production
h

4h housing, 2h hotel

°C

8°C winter, 15°C summer

%

10-20% depending on network

📊DHW sizing

🛢️Tank volume

300L

🔥Production power

8,8kW

💧Daily demand

1 050L/j

Gross demand at 60°C

20 dwellings × 75 L/dwelling

1 500L/jour

Peak volume

Over 4h with simultaneity 0.7

175L

Calculated storage volume

Storage factor: 100%

202L

ΔT

60°C storage — 10°C cold water

50°C

Daily energy

61,1kWh/j

Estimated annual consumption

25,629kWh/an
💡
Storage must be at least 60°C for Legionella prevention. Distribution ≥ 50°C at all points.
📐 Sizing formulas
V_jour = N × q × Cs = 20 × 75 × 0.7 = 1050 L/j P = V × Cp × ΔT / t Cp = 1.163 Wh/L·°C Énergie = V × Cp × ΔT = 61.1 kWh/j

N = number of units, q = unit demand (L/d at 60°C), Cs = simultaneity factor, Cp = specific heat of water, ΔT = temperature difference.

Standards & regulations

  • DTU 60.11Règles de calcul des installations de plomberie sanitaire
  • Arrêté 30/11/2005Prévention du risque lié aux légionelles dans les ERP
  • NF EN 12831-3Calcul des besoins en eau chaude sanitaire

This tool provides indicative estimates. Results do not substitute professional advice. Always verify with current regulations.

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