Page 385 - Divyank Tyagi

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energy MoDeling 351

5. Repeat steps 3 and 4 for all the Mass Exterior Wall surfaces on the two flat sides of the
massing form.

Because these surfaces are oriented toward the north, we may be able to avoid the cost
of the sunshades and increase the glazing area to allow more natural light into the
interior spaces for a possible reduction in artificial lighting costs without increasing solar
heat gain.
6. From the Analyze tab, click Run Energy Simulation. Set the Run Name to North Faces
Refined, and make sure to select the Use Existing radio button and choose your existing
project from the drop-down list.
7. When the simulation is complete, click the Results & Compare button in the Analyze
tab of the ribbon. In the Results And Compare dialog box, select both the North Faces
Refined and Shading + HighPerfGlass runs, and then click Compare.
Examining the results in these two examples may reveal some interesting comparisons.
It seems that the overall energy use intensity (EUI) and carbon emission are estimated to be
higher with the refined model than the previous run that included sun shading and high-
performance glazing on the entire exterior enclosure (Figure 9.37). By increasing the percentage
of glazing on the northern faces, we may be increasing the amount of natural light, but we are
also increasing the surface area of a less-efficient enclosure material. As a result, the winter
heating load increases.

Figure 9.37
Comparing carbon
emissions between
two simulation
runs

As a final exercise to examine methods for refining your conceptual analysis model, we
will add an extruded in-place mass that will represent a slightly more accurate depiction of a
building core. As we mentioned earlier in this chapter, the Divide Perimeter Zones option in the
Energy Settings dialog box is checked by default. This setting creates a simulated zone that is
offset from the exterior face of the massing form (Figure 9.38). If the exterior faces of the massing
form are irregularly shaped, the simulated core will be irregularly shaped as well.

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