High Performing Buildings - Fall 2010 - (Page 19)

controlled by software installed on the user’s personal computer that allowed users to adjust light levels, occupancy-sensor time-out period and daylight settings. These light fixtures, however, proved to be problematic because of frequent software conflicts with user’s computers, occupancy-sensor false tripping, daylight harvesting controls that dimmed but could not shut off lights when adequate daylight was available, and dimming ballasts that reduced light levels to 10% but only reduced energy consumption to 30%. These lights have been retrofitted with a more elegant wireless control system provided by a different manufacturer. The lights have similar functionality but more reliable Internet-based controls offer a more easily understood interface and dashboard. Importantly, lights switch off completely when adequate daylight is available. People determine how bright they perceive a space to be based on a number of criteria. In addition to contrast levels and age, a key factor affecting this perception is the luminance of the main surfaces in the visual plane. In a typical office, 40 footcandles on an empty desk does nothing to affect an occupant’s impression of brightness, while placing the same amount of light on a white wall in the occupant’s visual plane will. Therefore, a key strategy in the design of the studio was to use high reflectance (80%) acoustic ceiling tiles and high reflectance (89%) paint on the walls, and then light them. The design for the studio space uses primarily daylight as a light source during daylight hours. However, during the evening indirect linear fluorescent lights provide an ambient light level, directing light on the ceilings and walls. These lights provide about 15 footcandles on the desks at night. Although well below IES recommended levels, very few staff use additional LED task lighting. plug loads IDeAs phased out older computers in favor of newer dual-core and quad-core computers with highefficiency power supplies. CRT monitors were replaced with low power LCD screens with incorporated speakers. Data and telecom flows are transmitted through CAT6A HPB.hotims.com/33325-10 http://www.cpidaylighting.com http://www.cpidaylighting.com http://HPB.hotims.com/33325-10

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