Liliana Beltran

Advanced Optical Daylighting Systems: Light Shelves and Light Pipes

We present two perimeter daylighting systems that passively redirect beam sunlight further from the window wall using special optical films, an optimized geometry, and a small glazing aperture. The objectives of these systems are (1) to increase daylight illuminance levels at 4.6-9.1 m (15-30 ft) from the window aperture with minimum solar heat gains and (2) to improve the uniformity of the daylighting luminance gradient across the room under variable solar conditions throughout the year. The designs were developed through a series of computer-assisted ray-tracing studies, laser visualization techniques, and photometric measurements and observations using physical scale models. Bi-directional illuminance measurements in combination with analytical routines were then used to simulate daylight performance for any solar position, and were incorporated into the DOE-2.1E building energy analysis computer program to evaluate energy savings. Results show increased daylight levels and an improved luminance gradient throughout the year compared to conventional daylighting systems.

Framework for Selecting Performance Assessment Tools for Achieving LEED 3.0 Credits

Architects, designers and engineers involved in a sustainable design project often require information and tools beyond energy simulation software. They look for tools to support their decisions and to assess the risk involved in decision making. This research presents a framework that links building performance assessment tools with the Leadership in Energy and Environmental Design (LEED) rating system. The objective is to bridge the gap between architects, engineers, contractors, facility managers and LEED professionals. This work provides information about performance tools that can be used in the different phases of design, construction and operation of a LEED-rated building. This research presents a three-dimensional matrix of the ‘right tool for the right job at the right time’ by linking LEED credits, software tools and phases of building design, construction and operation. Overall, the findings of the research demonstrate that the framework can be used to achieve 21% of total possible LEED 3.0 credits by providing about 36% of total possible points.

Advanced optical daylighting systems: light shelves and light pipes

We present two perimeter daylighting systems that passively redirect beam sunlight further from the window wall using special optical films, an optimized geometry, and a small glazing aperture. The objectives of these systems are (1) to increase daylight illuminance levels at 4.6-9.1 m (15-30 ft) from the window aperture with minimum solar heat gains and (2) to improve the uniformity of the daylighting luminance gradient across the room under variable solar conditions throughout the year. The designs were developed through a series of computer-assisted ray-tracing studies, laser visualization techniques, and photometric measurements and observations using physical scale models. Bi-directional illuminance measurements in combination with analytical routines were then used to simulate daylight performance for any solar position, and were incorporated into the DOE-2.1E building energy analysis computer program to evaluate energy savings. Results show increased daylight levels and an improved luminance gradient throughout the year compared to conventional daylighting systems.