Case History
SRG PARTNERSHIP
Da Vinci Arts Middle School
Portland, Ore.
Da Vinci is an arts magnet school sited at sea level in an urban
residential neighborhood, about a mile east of the center of
Portland. The parent organization has been very active in raising
money to build the new 900-square-foot LEED-certified classroom,
now under construction.
The central skylight, with its automatic light louvers, slopes to
the south, and more light is admitted by a line of high windows
placed high on the south wall where they’re shaded by the eaves.
These windows can be opened to aid airflow through the classroom
and out the dramatic thermal chimneys. Additional ventilation is via
the louvers adjoining doors on the north and south walls.
Architect: SRG Partnership
standards. Even during the short days of Oregon’s midwinter, we
measured adequate daylight from 8: 30 to 3: 30 to illuminate the classroom tasks. Our first step was to create a design that would bring daylight indoors, and diffuse it evenly to all corners of the room.
Toplighting is the most efficient method to achieve the target illumination levels in the classroom because, unlike vertical glazing, the
opening is exposed to the whole sky dome. Therefore, the high-performance classroom utilizes a central skylight to provide lighting.
This skylight features the CPI ControLite product, a system that
integrates adjustable louvers within its polycarbonate glazing to moderate the amount of light and therefore the heat transmitted. The control system moderates lighting levels in the classroom to maintain
steady lighting intensities under changing sky conditions.
One of the problems with using a large, single skylight to daylight
a space is that the areas under the skylight is often more brightly lit
than those farther away, creating varied illumination levels and poor
lighting quality in the room. To solve these distribution problems we
used a suspended light reflector along with a sloped ceiling plane to
redirect and evenly distribute daylight throughout the room and
eliminate hot spots. Full-scale testing resulted in a design prototype
that can operate during daylight hours without the use of electric
lights, eliminating that building load.
Heat flow and energy storage: The first step to eliminating heating and cooling loads is to create a tight envelope, eliminating infiltration. Infiltration allows conditioned air to escape the building
and unconditioned air to invade. Adding insulation to the envelope
reduces the exchange of energy between the interior and exterior. A
well-insulated building has lower heating and cooling loads as a
result of the limited transfer of energy.
Our high insulation values reduced heating and cooling loads to
the point where passive systems can meet the building’s needs.
In the winter, the body heat of occupants is sufficient to keep the
classroom comfortable.
During the summer, cooling is accomplished using a night venti-
lation strategy that takes advantage of the diurnal temperature change
in our Pacific Northwest climate. At night, vents and thermal chimneys are opened by automatic controls to flush the classroom with outside air. The night air cools the thermal mass in the floors and walls.
During class hours, inlets and outlets are closed to prevent infiltration
of sun-warmed outside air. The cooled thermal mass absorbs heat from
occupants, equipment and solar gain.
When outside air is required during school hours, the incoming
air is tempered with the exiting conditioned air using a heat
exchanger. This helps to keep the building load as low as possible.
Finally, when the classroom is used after dark, especially in winter, supplemental light and heat are provided by four sets of two T5
fluorescent lamps mounted on top of the reflector’s diagonals.
Are we flexible? Loads are created to provide comfort for occupants. If we are flexible about what we accept as comfortable — that
is, if we move beyond conventional assumptions about air movement,
humidity and temperature ranges — it turns out that simple, inexpensive ceiling fans can often substitute for complex air conditioning systems when a night ventilation of mass strategy is used.
Through the use of theoretical concepts and full-scale prototypes
we have demonstrated 70 percent less energy use than classrooms built
to Oregon Code, at a lower cost than typical classroom construction.
Real-world experience with new high-performance classrooms at
three Oregon schools shows that the future of the high-performance
classroom design looks bright. ●
G.Z. Brown is founding director of the Energy Studies in Buildings
at the University of Oregon. Dylan Chavez and Terry Blomquist
are staff members there. They would like to acknowledge the
great number of contributors outside of our group who have
helped to make this project possible: The Northwest Energy Efficiency Alliance; The University of Oregon; Heinz Rudolf and Jerry
Conduff, BOORA Architects; Kent Duffy, SRG Partnership; Mt.
Angel Abbey; and Mike Hatten, Solarc Architects + Engineers.
They would also like to acknowledge the people within the lab
who have contributed to this project; Laura Wade Jensen, Jeff
Kline, Gina Livingston, Dale Northcutt, Mark Wilkerson, Jason
Stenson and Tom Nelson.
