Comfort Considerations in Net ZEBs: Theory and Design - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 137

is the angle between line of sight and line from eye to source (°), is the
distance between eye and plane of source, in the view direction, is the
vertical distance between source and view direction, and is the horizontal
distance between source and view direction.
3.3.5 Daylight and Occupant Behavior
The last aspect described in this section is about the interaction between
occupants and the daylighting/lighting domain. Dynamic window shading
devices are normally installed with the design intent to be temporarily
closed to provide privacy and protection from glare, while remaining partly
or fully open to exploit daylight and passive solar gains, when possible.
However, observations have revealed that occupants tend to be inactive
users of shading systems (e.g., blinds and roller shades). The mean rate of
shade movement is well below once per day for most office buildings with
some shades being never moved (Van Den Wymelenberg, 2012). Instead of
being highly responsive to daylight conditions, occupants tend to leave their
shades in a position that “causes the least trouble” (Bordass et al. , 2001) or
minimizes conflict between occupants in shared offices (Cohen etal. , 1999),
namely, partly or fully closed. This leads to reduced views and unnecessary
electric lighting use that ultimately increases energy use relative to what
designers predicted. An effective daylight design should create a pleasant,
glare-free environment, so as to minimize actions that will reduce daylight
admission (Boyce, Hunter, and Howlett, 2003), while exploiting daylight.
Good passive and indoor design, such as window geometry, window type,
fixed exterior shading, interior design surface reflectances, and strategic
furniture layout, can reduce the frequency of closed shades and increase the
daylight utilization and view to the outdoors. Moreover, field surveys reveal
that occupants value some degree of individual control over the shading
devices and windows (Leaman and Bordass, 2005). This aspect cannot be
ignored as occupants are significantly less active and energy-conserving
than designers might expect.
3.4 Acoustic Comfort
Acoustic comfort describes the indoor acoustic conditions of a building with
regard to providing a healthy and productive environment for occupants.
It is critical to properly functioning buildings, yet often neglected during
design and in green building standards (Hodgson, 2008). Acoustic comfort