Page 12 - 14th @ Irving Basis of Design (internal)

Preliminary analysis indicates that an array this size with a conservative 13% efficient photovoltaic modules would generate 95,000
kWh of electricity per year, which equates to 28.7 mt CO2/e in avoided emissions. Depending on module selection and energy
performance achieved, the array could cover between 1% and 5% of the building’s energy use, easily offsetting roof terrace or living
room lighting and earning four points in the LEED-CS certification.

Opaque thin-film panels Translucent amorphous
panels at balcony wall

Bifacial frameless Façade-integrated
modules installation

Electricity generation will scale with the cell coverage of the PV panels. Visual examples of some options show variation in aesthetics and
installation strategies. The basis of design product is closest to that on the bottom left.

DAYLIGHT QUALITY
14 @ Irving’s open, highly glazed design lends itself to quality daylighting, which can reduce electric lighting energy and
th
associated cooling loads. Access to daylight provides measurable benefits in offices, where workers may experience eye strain from
extended computer use or other detailed repetitive visual tasks. There is evidence that exposure to high levels of daylight during
appropriate hours has long-term health benefits for employees, reducing absenteeism by 15% and even improving the frequency of
exercise and activity throughout the day. Along with air quality, daylight is a key driver in the perceived indoor environmental
quality of a space. As a result, access to daylight is now considered an important amenity for the modern workplace.
As a proxy for evaluating daylight quality, a daylight analysis was conducted investigating spatial daylight autonomy (sDA) and
annual sunlight exposure (ASE), which are the two metrics included in the LEED v4 Quality Daylighting credit. Spatial daylight
autonomy measures the floor area which can be adequately lit through daylight alone for more than half of occupied daytime
hours, and sDA over 50% generally indicates that a floorplate receives good daylight access. Annual sunlight exposure measures the
floor area which experiences direct sunlight for more than 250 occupied daytime hours. ASE over 10% generally indicates a
potential problem with glare and high thermal loads.
Assuming a glazing visual light transmittance of 0.64, 61% of the front-of-house area can be adequately lit through daylight alone
for more than half of occupied daytime hours (sDA300,50). On the lower floors, due to contextual overshadowing, daylight levels
are lower in the core. These floors should be served well by the ASHRAE 90.1 prescriptive requirements for perimeter daylight
sensors.

14th @ IRVING WSP
Project No. B1809809.000
RAL COMPANIES & AFFILIATES Page 12