ASHRAE_K

This function returns the thermal conductivity of a material listed in the ASHRAE insulation and building-material tables. The conductivity is treated as a tabulated property for the selected material entry and does not vary with temperature in this lookup.

Thermal conductivity relates conductive heat flux to a temperature gradient through Fourier’s law:

q = -k\nabla T

where k is the thermal conductivity in W/m/K. Choose the material ID that matches the desired tabulated entry.

Excel Usage

=ASHRAE_K(ID)

• ID (str, required): Material ID from ASHRAE tables (dimensionless).

Returns (float): Thermal conductivity of the material (W/m/K).

Example 1: Mineral fiber conductivity

Inputs:

ID
Mineral fiber

Excel formula:

=ASHRAE_K("Mineral fiber")

Expected output:

0.036

Example 2: Glass fiber batts conductivity

Inputs:

ID
Glass-fiber batts, 90 mm

Excel formula:

=ASHRAE_K("Glass-fiber batts, 90 mm")

Expected output:

0.043

Example 3: Expanded polystyrene conductivity

Inputs:

ID
Expanded polystyrene, extruded

Excel formula:

=ASHRAE_K("Expanded polystyrene, extruded")

Expected output:

0.026

Example 4: Cellular glass conductivity

Inputs:

ID
Cellular glass

Excel formula:

=ASHRAE_K("Cellular glass")

Expected output:

0.048

Python Code

Show Code

from ht.insulation import ASHRAE_k as ht_ASHRAE_k

def ASHRAE_k(ID):
    """
    Return thermal conductivity for an ASHRAE material.

    See: https://ht.readthedocs.io/en/latest/ht.insulation.html

    This example function is provided as-is without any representation of accuracy.

    Args:
        ID (str): Material ID from ASHRAE tables (dimensionless).

    Returns:
        float: Thermal conductivity of the material (W/m/K).
    """
    try:
        result = ht_ASHRAE_k(ID)
        return float(result)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

ID *

Material ID from ASHRAE tables (dimensionless).