FH approach

As in the case of the F1 approach, the first step in setting up the FH method simulation is to assign the F aperture. The aperture for the FH approach, shown in Figure 64, should envelope the façade from all sides so that all directions of flux transfer from the façade to the sky are accounted for. Figure 65 provides a screen capture of the definition for the FH aperture (fports/FH.rad). As explained earlier, the FH aperture is assigned a single hemispherical sampling basis.

The F-Matrix can now be created with rfluxmtx as:

rfluxmtx -v -ff -ab 4 -ad 10000 -lw 1e-5 -c 5000 -n 8 objects/GlazingVmtx.rad fports/FH.rad -i roomFmtx.oct > matrices/fmtx/FH.fmx

The corresponding Daylight matrix can be created as:

rfluxmtx -v -ff -ad 10000 -ab 4 -lw 1e-5 -c 5000 -n 8 fports/FH.rad skyDomes/skyglow.rad -i roomFmtx.oct > matrices/dmtx/DFH.dmx

The F-Matrix and D-Matrix can now be merged into a single matrix by using dctimestep as:

dctimestep -of matrices/fmtx/FH.fmx matrices/dmtx/DFH.dmx > matrices/dmtx/DFH.dfmx

Figure 64. The FH aperture in the above is comprised of four polygons that account for flux transfer from the front, left, right and top of the façade. The directional-normal of each of the polygons must face towards the room.

Figure 65. A partial screen capture of the aperture of the FH aperture (fports/FH.rad). Although FH aperture consists of polygons whose directional-normals face in different directions, a single hemispherical sampling basis is employed. As indicated by the rfluxmtx comment in first line in the above figure, a full-klems basis with the hemisphere-up direction of +Z was assigned.

A comparison with the steps outlined in the previous section show that the Radiance syntax for generating F1 and FH matrices are identical. The steps for generating results with this approach are described in section 7.5.