Energy
Pipe Insulation Heat Loss Calculator
Calculate heat loss through insulated piping from pipe diameter, insulation thickness, thermal conductivity and temperature difference.
Use thermal conductivity at a representative mean insulation temperature where available.
Editable combined external coefficient assumption. Actual value depends on air movement, orientation and radiation effects.
Optional. Leave blank if you only need heat-loss rate.
Optional cost per kWh of supplied heat or energy.
Pipe Heat Loss
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Estimated heat loss per metre of insulated pipe.
Heat loss per metre
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Total heat loss
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Annual energy loss
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Annual energy cost
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Outer insulation diameter
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Insulation resistance
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External resistance
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Temperature difference
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Method:
Heat loss through cylindrical insulation is estimated using thermal resistance.
Insulation conduction resistance is:
Rins =
ln(r₂ / r₁) ÷
(2πkL)
External heat-transfer resistance is:
Rext =
1 ÷
(h × 2πr₂L)
Total heat loss is:
Q =
(Tpipe − Tambient) ÷
(Rins + Rext)
where:
r₁ = pipe outside radius
r₂ = outer insulation radius
k = insulation thermal conductivity
h = external heat-transfer coefficient
L = pipe length
Heat loss per metre is calculated using the same equations for a one-metre pipe length.
If operating hours are entered:
Energy Loss =
Heat Loss × Operating Hours
If energy cost is also entered:
Annual Cost =
Energy Loss × Energy Cost
This is a simplified steady-state model. It assumes one uniform insulation layer, constant thermal conductivity, uniform pipe surface temperature and a single external heat-transfer coefficient.
Radiation is not calculated separately. If the entered external coefficient is intended to represent combined convection and radiation, it should be selected accordingly.
Real installations can differ because of insulation joints, supports, valves, flanges, weather cladding, wind, moisture ingress, surface emissivity, thermal bridges and temperature-dependent insulation properties.