Thermal Resistance Network

mechanical

Calculates heat transfer through multi-layer flat walls or cylindrical pipes using thermal resistance networks. Looks up thermal conductivity for each layer from reference tables. Computes individual and total thermal resistances, steady-state heat flow rate Q, overall heat transfer coefficient U, and interface temperatures at each boundary.

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Geometry*

Wall geometry. 'flat_wall' uses R = L/(kA) for each layer. 'cylindrical' uses R = ln(r_outer/r_inner)/(2*pi*k*L) for radial conduction through pipes/tubes.

Layers*

Ordered list of material layers from innermost to outermost. Each layer specifies a material_id for conductivity lookup plus geometry (thickness_m for flat, outer_radius_m for cylindrical).

Area M2

Heat transfer area in m^2. This is the cross-sectional area perpendicular to heat flow. Only required when geometry is 'flat_wall'.

Length M

Axial length of the pipe/cylinder in meters. Only required when geometry is 'cylindrical'.

Inner Radius M

Inner radius of the innermost layer in meters. This is the pipe bore radius. Only required when geometry is 'cylindrical'.

h inner*

Inner surface convection specification. Provide either h_W_m2K directly or convection_type + scenario for table lookup.

h outer*

Outer surface convection specification. Provide either h_W_m2K directly or convection_type + scenario for table lookup.

T Inner C*

Bulk fluid temperature on the inner (hot) side in degrees Celsius. Heat flows from T_inner toward T_outer. Hot side temperature. Typical: 20-25 C indoor, 60-150 C for process piping.

T Outer C*

Bulk fluid/ambient temperature on the outer (cold) side in degrees Celsius. Cold side temperature. Typical: -20 to 35 C outdoor, 5-15 C for chilled surfaces.

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Reference data

This calculator pulls live values from the following engineering reference tables in the database.

thermal conductivity
convective htc

About this calculator

Thermal Resistance Network is part of the Engineering Database calculator suite. Each tool runs deterministic calculations against authoritative reference data and code-compliant methods, so results are reproducible and traceable to source standards.

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Reference data

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