Net ZEB Case Studies - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 441

Fig. 7.64 Simulated interior daylight illuminance distribution on the
workplane on a clear sunny winter day using radiosity method
7.4.3.3 Integrating Design and Control for Daylighting and Solar Heat
Gain - Option with Controlled Shading
Duringthewinterseason,thesolaraltitudeangleislowandhencecaneasily
penetrate deeply into perimeter zones and cause glare. Without suitable
daylighting and solar heat gain storage measures, blinds will likely block
this solar radiation potentially useful for passive space solar heating. On the
other hand, in the cooling season, excessive transmitted solar radiation can
increase the cooling load. Integrated daylighting and solar heat gain design
and control aims to maximize the utilization of solar radiation, not only for
daylighting, but for passive solar heating as well. The key design and control
elements will be the daylighting portion of the equator-facing window and
building-integrated thermal energy storage.
The integrated approach being investigated in this case study is to adopt
a Vision Control® (VC) window on the optimally sized equator-oriented
windows, and to use it to control the incoming amount of solar radiation
to satisfy daylighting and solar heat gain requirements. The VC window
has highly reflective blinds between two glass panes. The blinds can be
rotated to block direct solar radiation penetration, and reflect the radiation
to desired surfaces (normally the ceiling) to allow it to reach deeper into
the space. This way, glare from direct sunlight can be avoided, and solar
radiation and daylight can be better utilized. Figure 7.65 shows the VC