Materials

Thermal Cable Model includes a built-in database of thermal material properties sourced from IEC 60287-2-1 and standard reference tables. All quantities are in SI units.

The `ThermalMaterial` class

Each material is described by:

Property	Unit	Description
`thermal_conductivity`	W/(m·K)	λ — thermal conductivity
`thermal_resistivity`	(K·m)/W	ρ = 1/λ
`volumetric_heat_capacity`	J/(m³·K)	ρ_m · c_p

The derived property thermal_diffusivity is computed as α = λ / (ρ_m · c_p).

You can create a custom material using the from_conductivity() class method:

from thermal_cable_model import ThermalMaterial

my_soil = ThermalMaterial.from_conductivity(
    name="Sandy soil",
    conductivity=1.5,                # W/(m·K)
    volumetric_heat_capacity=2.0e6,  # J/(m³·K)
)

Built-in materials

Conductor materials

Constant	λ [W/(m·K)]	ρ [(K·m)/W]	ρc_p [MJ/(m³·K)]
`COPPER`	385	0.0026	3.45
`ALUMINUM`	230	0.0043	2.42

Insulation materials (IEC 60287-2-1)

Constant	λ [W/(m·K)]	ρ [(K·m)/W]	ρc_p [MJ/(m³·K)]
`XLPE`	0.286	3.5	2.4
`PVC`	0.167	6.0	1.7
`EPR`	0.286	3.5	2.4
`PAPER_INSULATION`	0.167	6.0	2.0

Jacket / bedding / filler

PVC_JACKET, PE_JACKET, POLYPROPYLENE_FILLER

Metallic layers

LEAD_SHEATH (λ = 35 W/(m·K)), STEEL_ARMOUR (λ = 50 W/(m·K))

Soil types

Constant	λ [W/(m·K)]	ρ [(K·m)/W]	ρc_p [MJ/(m³·K)]
`SOIL_DRY`	0.83	1.2	1.3
`SOIL_WET`	1.43	0.7	2.5
`SOIL_STANDARD`	1.0	1.0	1.8
`THERMAL_BACKFILL`	2.0	0.5	2.2
`CONCRETE_DUCT`	1.2	0.83	2.0

Other

AIR_STILL (λ = 0.025 W/(m·K)) — for duct installations.

The `MATERIALS` dictionary

All built-in materials are also available as a name-keyed dictionary:

from thermal_cable_model import MATERIALS

soil = MATERIALS["Standard soil (ρ=1.0)"]