Thermal Conductivity Calculator Formula

Understand the math behind the thermal conductivity calculator. Each variable explained with a worked example.

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Formulas Used

Heat Flow Rate

heat_rate = conductivity * area * delta_t / thickness

Variables

VariableDescriptionDefault
conductivityThermal Conductivity (k)(W/(m·K))0.04
areaArea(m²)10
delta_tTemperature Difference(°C)20
thicknessMaterial Thickness(m)0.1

How It Works

Thermal Conductivity (Fourier's Law)

Fourier's law describes the rate of heat conduction through a material.

Formula

Q/t = k * A * DeltaT / d

where k is thermal conductivity, A is area, DeltaT is temperature difference, and d is thickness. Lower k means better insulation.

Worked Example

Heat loss through a 10 m² wall, 10 cm fiberglass insulation (k=0.04), 20°C temperature difference.

conductivity = 0.04area = 10delta_t = 20thickness = 0.1
  1. 01Q/t = k * A * DeltaT / d
  2. 02Q/t = 0.04 * 10 * 20 / 0.1
  3. 03Q/t = 8 / 0.1
  4. 04Q/t = 80 W

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