Conductive Heat Transfer Calculator
Calculate steady-state conductive heat flow through walls, insulation layers, and heat exchanger surfaces using Fourier's Law of Heat Conduction.
Use this free calculator to determine the rate of conductive heat transfer through a flat wall or slab. This tool is widely used in chemical engineering for insulation design, heat exchanger analysis, and energy loss estimation.
Conductive Heat Transfer Calculator
Fourier's Law of Heat Conduction
Steady-State Conduction through a Flat Wall:
\[ q = \frac{k}{s} \times A \times (t_1 - t_2) \]
Where: q = heat transfer rate (W), k = thermal conductivity (W/(m·K)), s = thickness (m), A = area (m2), t1, t2 = surface temperatures (°C or K).
Thermal Resistance (R):
\[ R = \frac{s}{k \times A} \]
Thermal resistance is the reciprocal of thermal conductance. Higher R-values indicate better insulation performance.
What is Conductive Heat Transfer?
Conductive heat transfer is the process by which thermal energy moves through a solid material from a region of higher temperature to a region of lower temperature, without any bulk motion of the material itself. It is governed by Fourier's Law of Heat Conduction, which states that the rate of heat flow is proportional to the temperature gradient and the cross-sectional area.
In chemical engineering, conductive heat transfer calculations are essential for:
- Designing insulation for pipes, vessels, and reactors
- Sizing heat exchanger walls and tubes
- Estimating heat losses from storage tanks and furnaces
- Evaluating thermal performance of building envelopes in plant facilities
Common Thermal Conductivity Values
| Material | k (W/(m·K)) | Typical Use |
|---|---|---|
| Copper | 385 | Heat exchanger tubes |
| Carbon Steel | 45 – 54 | Process piping, vessels |
| Stainless Steel 304 | 14 – 16 | Corrosive service |
| Glass | 0.8 – 1.0 | Sight glasses, linings |
| Brick (common) | 0.6 – 1.0 | Furnace walls |
| Fiberglass Insulation | 0.03 – 0.05 | Pipe & tank insulation |
| Mineral Wool | 0.03 – 0.04 | High-temp insulation |
| Air (still) | 0.026 | Gap reference |
References & Further Reading
- • Incropera, F.P., et al. (2011). Fundamentals of Heat and Mass Transfer (7th ed.). John Wiley & Sons. (Fourier's Law derivation and material properties)
- • Holman, J.P. (2010). Heat Transfer (10th ed.). McGraw-Hill. (Thermal resistance networks and insulation design)
- • Cengel, Y.A. (2014). Heat and Mass Transfer: Fundamentals and Applications (5th ed.). McGraw-Hill. (Practical engineering applications and tables)
- • Perry, R.H. & Green, D.W. (2018). Perry's Chemical Engineers' Handbook (9th ed.). McGraw-Hill. (Industrial thermal conductivity data)
Frequently Asked Questions
Fourier's Law states that the rate of heat transfer through a material is proportional to the negative temperature gradient and the area through which the heat flows: q = −k·A·(dT/dx). For a flat wall with constant conductivity, it simplifies to q = (k/s)·A·ΔT.
Heat transfer is inversely proportional to thickness. Doubling the wall thickness halves the heat flow (assuming all other parameters remain constant). This is why thicker insulation reduces heat loss.
This calculator is designed for flat walls. For cylindrical geometries (pipes), the logarithmic mean area must be used. Please refer to specialized pipe heat loss calculators for cylindrical conduction.
The calculator allows you to toggle between Metric (SI) and Imperial (US) units for each input. It automatically converts all values to base SI units internally to ensure accurate calculations, then displays the results in standard SI units (Watts, W/m2, K/W).