Steady-state conduction through a plane wall: Q = k·A·ΔT / L. The U·A building block for every insulation calculation.
Formula
$$ Q = \frac{k \cdot A \cdot \Delta T}{L}, \quad U = \frac{k}{L} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $k$ | Thermal conductivity | W/(m·K) | material spec |
| $A$ | Heat-transfer area | m² | geometry |
| $L$ | Wall thickness | m | construction |
| $ΔT$ | Temperature difference | K | operating condition |
| $Q$ | Heat flow | kW | result |
Sources
- Incropera - Fundamentals of Heat and Mass Transfer.