Page 29 - Zero Net Energy Case Study Buildings-Volume 1

PACKARD FOUNDATION HEADQUARTERS BUILDING CASE STUDY NO. 1
manager as well as access to building performance information by others. A diagram of the au- tomated controls system developed for this project is shown on the opposite page.
The Packard Foundation regarded the development of this system as a “grand experiment”, its technical contribution to the success of this particular project. But the Foundation also regarded this as a pioneering effort in an area of technology that needs to be improved quickly, with plans to share this information with the building industry so that future zero net energy building projects can use this type of system “off the shelf” with low perceived risk.
This innovation, developed by the client’s own staff of experts, has demonstrated successful operation over its entire occupancy period to date and is largely responsible for making this par- ticular case study a new paradigm for building design.
Natural Ventilation
The building control system manages the operation of the exterior window shading, but the room occupants have complete control over the openable windows. The HVAC system is capable of meeting all cooling and fresh air requirements, so the natural ventilation is intended to provide users with a sense of control over their own comfort conditions as well as to reduce the cooling load when used by the occupants. This has two good outcomes: (1) user perception of a zero- net-energy building is one of comfort rather than the opposite; (2) HVAC cooling temperature setpoints can be higher than standard since the air movement of natural ventilation provides a sense of cooling comfort at higher air temperatures.
As a guide to the occupants about managing their own environments for comfort and low energy use, the Packard Foundation IT staff created some simple apps, so to speak, to alert them about changing outdoor conditions and as an advisory about beneficial actions to take if they choose to. Residing in the dock of each occupant’s computer monitor is a natural ventilation status icon—either a green up-arrow or a red down-arrow—which his set by the building’s automation control system. When the green arrow is present, windows may be opened for natural ventila- tion; when the red arrow is present, windows are recommended to be closed. When conditions change from one to the other, a pop-up similar to an email notice appears on the monitor as an alert. (See illustration below.)
These unobtrusive visual devices, while guiding user intervention in the operation of the building systems, nevertheless allow the occupant to determine the best personal conditions for comfort.
(Above) Interior light shelves to improve daylight penetra- tion in exterior office spaces.
Zero Net Energy Case Study Buildings: Volume 1
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(Left) Image on computer screen of all staff, showing natural ventilation app and pop-up notices about option to open windows.(Image cour- tesy of Packard Foundation)