High Performing Buildings - Fall 2010 - (Page 38)

All artificial lights are off in this typical elementary classroom. exterior shading devices protect view windows from direct sunlight, while fixed parabolic light louvers cast an even warm light across the tilted ceiling plane. the teaching wall is glarefree, which is even more critical when using a SMARtboard (an interactive projection display). When the lights are on, each row automatically dims to provide only the illumination needed to supplement the daylight. Favorable conditions are signaled by green lights that are tied to the building automation system. the outdoor temperature must be between 60°F and 75°F, and the chance of rain must be less than 40% to trigger the ‘green light mode.’ the signal lights make the children active participants in energy conservation. the students are the first to open the windows, and when the light turns off, they quickly remind teachers that open windows need to be shut tightly. the sustainable feature with the greatest differential first cost is the ground-source heat pump mechanical system, which includes 221 vertical bores of 350 ft each. Life-cycle cost analysis predicted a payback in seven to nine years. In contrast, the rainwater harvesting system has a longer payback. the importance of water conservation, the educational benefits of the system, and the ability to serve as a demonstration project swayed the owner to invest in this system. this decision was subsequently made easier by a $50,000 grant from the Virginia Department of conservation and recreation. Bioclimatic design the building form and height are greatly influenced by the site constraints, which offered only a narrow area (stretching southwest to 38 HigH Performing northeast) for building. to optimize daylighting in the principal learning spaces, classrooms are organized into three “academic houses.” each classroom faces 13° from north or south. the three-story educational houses (nearly cubic in volume) minimize building envelope exposure to the climate. the houses are organized around 70 ft wide courtyards, which is a distance that allows sunlight to reach each house’s entire southern elevation on the winter solstice. Mature deciduous trees, on rising ground to the west, shade the buildings from the setting sun. the relatively exposed east side of the building is programmed with closed spaces (gym, loading dock, mechanical rooms) to minimize unwanted solar heat gain. although the temperate seasonal climate is humid with light and variable winds, natural ventilation is used for cooling when conditions are favorable. an induced stack effect, established by vertical ventilation ducts, draws fresh air in through manually operable windows and exhausts air through the penthouses. sam Kittner and Vmdo Architects key sustainaBle Features Water Conservation mPes used 84.5% less potable water than its neighboring school (45 gallons/occupant per year compared to 320 gallons/occupant per year). savings are achieved through lowflow lavatories and harvested rainwater used for toilet flushing and all irrigation. recycled materials The project was built using 20.2% recycled materials, and 98.9% of the construction waste was diverted from the landfill. daylighting Properly oriented and shaded glazing, dimmable tubular skylights, light redirecting louvers (in lieu of light shelves) and sloped, white ceilings provide natural light to 78.7% of the regularly occupied spaces. Photosensors in classrooms automatically dim individual rows of pendant fixtures. individual Controls each of the 59 classrooms has its own dedicated ground-source heat pump. Heating and cooling setpoints are set via the BAs, but users can adjust the setpoint two degrees in either direction. lights can be switched on using only half of the lamps, which is the default setting. natural Ventilation A green light system lets students know that windows may be opened. Compressors in the heat pumps turn off, and a fan assisted stack effect pulls fresh air through the room. The green light turns off when the system switches back to mechanical conditioning, alerting teachers and students to shut the windows. Buildings fa l l 2 0 1 0

Table of Contents for the Digital Edition of High Performing Buildings - Fall 2010

High Performing Buildings - Fall 2010
Table of Contents
IDeAs Z2 Design Facility
Lighting Design Alliance
Manassas Park Elementary School and Prekindergarten
FC Gulf Freeway Office Building
Capturing Condensate
National Australian Built Environment Rating System
Tyson Living Learning Center

High Performing Buildings - Fall 2010