Page 78 - Zero Net Energy Case Study Buildings-Volume 2

CASE STUDY NO. 9
SPECULATIVE OFFICE BUILDING AT 435 INDIO WAY
Master System Integration and Control Systems
This case study building benefited from the experience with ZNE buildings over the past several years and the evolving understanding in the industry about the importance of master system in- tegration for the various control systems used in “smart buildings” such as ZNE performers. The owner contracted with a building controls (“Building OS”) software company5 during the design phase to advise on the overall controls for this case study building. Understanding the state of the controls industry at the time, the software company hired an experienced independent mas- ter system integrator6 to advise on how to proceed.
The arrangement evolved so that the integrator became a member of the design-build team, working with the designers and in the field to develop an omni-controller that functioned smoothly according to the defined sequence of operations for all passive system controls (sensors, win- dow and skylight actuators, room fans, etc.) as well as the standard HVAC system controls. After the commissioning was completed, the integrator was engaged under a facilities maintenance contract by the owner to monitor the omni-controller and the connected systems, to ensure con- tinued quality performance.
The integrator based the design of the omni-controller on a residential version of an building industry control system7 and implemented a BACnet8 communications protocol with it so that the system could communicate with the HVAC system, for which BACnet is standard.
The design of the omni-controller also included another innovation: the sequence of operations for the passive systems requires that a signal be sent to the actuators of windows and skylights for a range of operation. The integrator developed communication software for both wired and wireless connection to the microprocessors of the actuators. For the wired applications, a univer- sal powerline bus (UPB)9 was used. For the wireless applications, the integrator used ZigBee10. The actuators specified did not allow partial opening set points, but only “open”, “close” and “stop”, so the integrator attached a timer and tuned the system so that the actuators could stop at various degrees of openness.
Lighting controls are left as a stand-alone system, built into the light fixture system as part of the manufactured design11. The metering of electric energy use was also initially left as a stand- alone system, connected to the cloud-based data recording system and the building’s energy dashboard. However, this was changed after ten months of occupancy to a connection with the omni-controller so that the integrator could have access to the building performance data as part of the overall monitoring of the building systems. (See Post Occupancy: Observations and Conclusions, below.)
5 Lucid, https://lucidconnects.com/
6 Intertie Automation, San Francisco, CA
7 Leviton, http://www.leviton.com/OA_HTML/SectionDisplay.jsp?section=37575&minisi te=10251
8 BACnet is a communications protocol for building automation and control networks. It is an ASHRAE, ANSI, and ISO 16484-5 standard protocol.
9 Universal Powerline Bus (UPB) is a communication protocol for sending digital signals be- tween devices using electric power line wiring for signal and control.
10 Zigbee is an IEEE 802.15.4-based specification for a suite of communication protocols used to create local area wireless networks of very low power. “ZigBee is the only open, global wire- less standard to provide the foundation for the Internet of Things by enabling simple and smart objects to work together...“, from http://www.zigbee.org/.
11 Enlighted Inc., http://www.enlightedinc.com/
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Zero Net Energy Case Study Buildings: Volume 2