Thermodynamics
Heat Transfer & Thermal Power
Calculate heat transfer rate through a wall or surface (conduction/convection), essential for cooling system design, panel thermal management and process heating.
Units:
Poor thermal management is a leading cause of electronic and motor failures. Control panel temperature should remain below 35–40°C inside. Every 10°C increase above rated temperature halves component lifetime (Arrhenius rule).
Q [W] = U × A × ΔT | U = 1 / (1/h₁ + d/λ + 1/h₂) [W/m²K]
Input
Overall heat transfer coeff. U iOverall heat transfer coefficient. Steel panel to still air: ~5 W/m²K. With forced convection: 10–30. Insulated wall: 0.3–2.
W/m²K
Transfer surface area A iEffective heat transfer area in m².
m²
Hot side temperature iTemperature of the hot side (e.g. inside cabinet) in °C.
°C
Cold side temperature iTemperature of the cold side (e.g. ambient) in °C.
°C
Result
Temperature difference ΔT [K]
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Heat transfer rate Q [W]
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Heat transfer rate Q [kW]
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Heat flux q [W/m²]
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