swings of 40°F, the concept relies
heavily on nighttime cooling of the
thermal mass in the floor slab and
existing tilt-up concrete walls, which
were intentionally insulated on the
exterior and left exposed on the
interior. This strategy has greatly
reduced cooling load and shifted
peak closer to after hours.
To further promote natural venti-
lation, ceiling fans were installed
with varying speeds, maintaining a
comfortable environment. Due to the
passive architectural design strate-
gies, we were able to reduce the size
and complexity of the HVAC systems
for the building from a typical 350
ft2/ton to over 1,200 ft2/ton.
For the passive system to work well
as intended, the design-build team
collaborates with a master system
integrator hired by the developer
on the overall controls. An omni-controller was developed to function
smoothly according to the defined
sequence of operations for all the
system components (sensors, window
and skylight actuators, room fans,
etc.) as well as the standard HVAC
system controls. The windows and
skylights are both equipped with
actuators that can respond to signals
for a range of operation.
To further reduce energy consumption, circuit metering was installed to
provide feedback on a tenant’s plug
load use. It turns out that the monitoring provided an alert to the tenant
that a batch of equipment is using
excessive amounts of energy compared to energy-efficient alternatives.
The tenant realized that replacement
of their old equipment, which was
driving the high energy consumption,
would be a cost-effective action and
developed a plan to do so.
glasses around the building. Cross-ventilation and stack effect were
both fully used to maximize the
effect of natural ventilation. The
design includes motorized operators
on all of the windows and skylights.
These are controlled with the BMS
based on external and internal temperatures. In a climate with diurnal
ABOVE The 32,000 square foot space is
100% daylit and 100% naturally ventilated.
RIGHT The back of house spaces were
laid out to allow for future tenant
This infographic shows the key strategies in the project: insulating envelope,
dynamic glass, operable windows and skylights, high thermal mass, ceiling fans,