HVAC & Ventilation
Pipe Heat Loss (Insulation)
Calculate heat loss from insulated hot/cold water pipes. Useful for heating, cooling and process piping systems.
Units:
For cold pipes (chilled water), heat gain causes condensation problems. Minimum insulation thickness to prevent condensation depends on ambient RH. For hot pipes, insulation payback is typically 1–3 years.
Q = 2π × λ × L × (T_pipe - T_amb) / ln(r_outer/r_inner)
Input
Pipe outer diameter iPipe outer diameter in mm. DN50: 60.3mm, DN80: 88.9mm, DN100: 114.3mm.
mm
Insulation thickness iInsulation layer thickness in mm. Typical: 20–80mm for process pipes.
mm
Insulation λ iThermal conductivity of insulation material. Mineral wool: 0.035–0.045, PIR foam: 0.022–0.028 W/mK.
W/mK
Pipe medium temperature iTemperature of the medium in the pipe in °C.
°C
Ambient temperature iAmbient (surrounding) temperature in °C.
°C
Pipe length iTotal pipe length in metres.
m
Result
Inner insulation radius [mm]
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Outer insulation radius [mm]
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Heat loss per metre [W/m]
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Total heat loss [W]
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Total heat loss [kW]
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Annual heat loss (8760h) [kWh/yr]
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