Smarter Heating & Hot Water

Volume Flow Rate Q Calculator

Calculate volumetric flow rate for central heating pump sizing and other heating system applications.

Φ = Heat demand in [kW] 5.0
tF = Flow pipe temperature [°C] 75
tR = Return pipe temperature [°C] 65
Volume Flow Rate
0.4300
m³/h
Volume Flow Rate
0.1194
L/s

Formula

Q = (Φ × 0.86) / (tF - tR)

Q = Volume flow rate
Φ = Heat demand (kW)
tF = Flow pipe temperature (°C)
tR = Return pipe temperature (°C)
0.86 = Conversion factor (kcal/h to kW)

Important: This calculator is for central heating pump sizing and system design. Always consult with a qualified heating engineer for your specific system requirements.