1. Eurocode 1: Actions on structures – Part 1–2: General actions – Actions on structures exposed to fire Part of the One Stop Shop program Annex G (informative) → Configuration factor

2. Introduction Measurement of the fraction of the total radiative heat leaving a given surface that arrives at a given receiving surface The value of the configuration factor depends on –Size of radiating surface –Distance between two surfaces –Relative orientation of surfaces “Position” effect and “Shadow” effect Calculation of temperatures in external members

3. Position and Shadow effects Position effect –Radiative heat transfer to an infinitesimal area of convex member surface is determined by the position and size of the fire only Shadow effect –Radiative heat transfer to an infinitesimal area of concave member surface is determined by the position and size of the fire as well as by the radiation from other parts of the member Combination of position and shadow effects –Rules for quantifying the shadow effect are given in material orientated parts of the Eurocodes

4. External members For the calculation of temperatures in external members, all radiating surfaces assumed rectangular –E.g. windows, doors, etc. in compartment walls See Annex B – Thermal actions for external members – the simplified calculation method The configuration factor determined in this Annex is used within Annex B

5. Rectangular envelope should first be drawn around cross-section of member Configuration factor The configuration factor is then determined for the mid-point P of each face of the rectangle

6. Configuration factor setup From point P, there are normally 4 zones visible on the radiating surface Radiating surface Receiving surface

7. Configuration factor setup Shadowing can result in some zones from not being visible from point P Radiating surface Receiving surface No contribution is thus taken from these zones and the configuration factor is taken as

8. Determination of factor If the surface receiving is parallel to the radiating surface - Height of zone on radiating surface - Width of zone on radiating surface - Distance from P to x This process is repeated for all visible zones of the radiating surface – normally 4 for parallel surfaces

9. Determination of factor If the surface receiving is perpendicular to the radiating surface - Height of zone on radiating surface - Width of zone on radiating surface - Distance from P to x This process is repeated for all visible zones of the radiating surface

10. Determination of factor If the surface receiving is at an angle to the radiating surface