Heat Loss Bare Surface

Overview

Engineering reference data for Heat Loss Bare Surface in heat transfer.

Key Formulas

Fourier's Law

$q = -k \nabla T$

Heat flux proportional to temperature gradient.

Convective Heat Transfer

$Q = hA(T_s - T_\infty)$

Heat transfer between surface and fluid.

Stefan-Boltzmann Law

$q = \varepsilon \sigma T^4$

Radiative heat flux from a surface.

Thermal Resistance

$R_{th} = \frac{L}{kA}$

Resistance to heat conduction.

Variables

Symbol	Description	Unit
$q$	Heat flux	W/m²
$k$	Thermal conductivity	W/(m·K)
$h$	Convection coefficient	W/(m²·K)
$T$	Temperature	K
$\varepsilon$	Emissivity	—
$\sigma$	Stefan-Boltzmann constant	5.67×10⁻⁸ W/(m²·K⁴)

Conditions and Assumptions

The data and diagrams for heat loss from bare pipes are based on the following conditions:

• Air Movement: Still air (natural convection only).
• Ambient Air Temperature: 70°F (21°C).
• Surface Emissivity ($\varepsilon$): 0.95.

These parameters are critical for accurately applying the general heat loss values, as both convective and radiative heat transfer are dependent on them.

References

• Original Source