Evaluation of lighting conditions in portable classrooms and analysis for alternative daylighting systems

Lighting conditions in multiple classrooms in central Texas were assessed, and the feasibility of improving portable classroom daylighting via alternative daylighting systems was also evaluated. Results indicate that surveyed portable classrooms generally provide sufficient levels of light with artificial lighting systems, but have less uniform lighting distribution than permanent classrooms. To evaluate the daylight availability in portable classrooms, a model was developed and verified using field data. Climate-based daylighting simulation was performed using DIVA for Rhino, which uses Radiance and DAYSIM as simulation engines. Results from the annual daylighting analysis suggest that limited amounts of daylight were available in portable classrooms over the course of a year. In order to assess the feasibility of improving portable classroom daylighting conditions, parametric studies were completed to investigate how different factors affect the levels of light in classrooms. Simulation results suggest that increasing window area and higher window placement allow more light into the classroom. Different external shading systems also affect the indoor daylight level. However, the impact of other factors, including building orientation, ceiling-to-floor height, and classroom length-to-width ratio is minimal. While changing the window systems for an existing portable building can require a large construction effort and financial commitment, retrofitting with tubular skylights is a more approachable option. Daylighting analysis shows eight 356-mm (14-inch) diameter tubular skylights can provide the portable classroom with a sufficient light level for more than 60% of occupied hours. When daylighting alone cannot provide sufficient light, lighting control will successfully combine a daylighting system and an artificial lighting system to provide an adequate lighting environment.Civil, Architectural, and Environmental Engineerin

High-Performance Integrated Window and Façade Solutions for California

The researchers developed a new generation of high-performance façade systems and supporting design and management tools to support industry in meeting California’s greenhouse gas reduction targets, reduce energy consumption, and enable an adaptable response to minimize real-time demands on the electricity grid. The project resulted in five outcomes: (1) The research team developed an R-5, 1-inch thick, triplepane, insulating glass unit with a novel low-conductance aluminum frame. This technology can help significantly reduce residential cooling and heating loads, particularly during the evening. (2) The team developed a prototype of a windowintegrated local ventilation and energy recovery device that provides clean, dry fresh air through the façade with minimal energy requirements. (3) A daylight-redirecting louver system was prototyped to redirect sunlight 15–40 feet from the window. Simulations estimated that lighting energy use could be reduced by 35–54 percent without glare. (4) A control system incorporating physics-based equations and a mathematical solver was prototyped and field tested to demonstrate feasibility. Simulations estimated that total electricity costs could be reduced by 9-28 percent on sunny summer days through adaptive control of operable shading and daylighting components and the thermostat compared to state-of-the-art automatic façade controls in commercial building perimeter zones. (5) Supporting models and tools needed by industry for technology R&D and market transformation activities were validated. Attaining California’s clean energy goals require making a fundamental shift from today’s ad-hoc assemblages of static components to turnkey, intelligent, responsive, integrated building façade systems. These systems offered significant reductions in energy use, peak demand, and operating cost in California

Review of simulating four classes of window materials for daylighting with non-standard BSDF using the simulation program Radiance

This review describes the currently available simulation models for window material to calculate daylighting with the program "Radiance". The review is based on four abstract and general classes of window materials, depending on their scattering and redirecting properties (bidirectional scatter distribution function, BSDF). It lists potential and limits of the older models and includes the most recent additions to the software. All models are demonstrated using an exemplary indoor scene and two typical sky conditions. It is intended as clarification for applying window material models in project work or teaching. The underlying algorithmic problems apply to all lighting simulation programs, so the scenarios of materials and skies are applicable to other lighting programs

A review of the lighting performance in buildings through energy efficiency

As developing countries including Malaysia, are now moving towards sustainable development is in line with the Ninth Malaysia Plan, 9th MP, the development should be built to meet current and future needs for achieving sustainability of economic development, social and environmental responsibility for the prosperity without compromising the future generations‘ needs. Over the past five years, there has been a move away from constructing new buildings to refurbishing older and historic ones. Thus, the purpose of this paper is to review and evaluate the approach for the refurbishment of lighting as well as the existing energy efficiency policy and measures in Malaysian historical building for the energy efficiency improvement in the future. The paper takes the form of a review of literature. The main sources of this literature research are based on the articles, journals, and internet search. This study perhaps can add to the breadth of knowledge of lighting performance in the historical building from the perspective of energy efficiency. This study offers new and valuable insights to Malaysia in achieving optimum energy efficiency, saving in financial as well as reducing environmental impact.This paper has been presented at 2nd International Conference on Research in Science, Engineering and Technology (ICRSET’2014) March 21-22, 201

Daylight and Architectural Simulation of the Egebjerg School (Denmark): Sustainable Features of a New Type of Skylight

This article discusses the performance of a new skylight for standard classrooms at the Egebjerg School (Denmark), which was built ca. 1970. This building underwent important reforms under a European project to which the authors contributed. This research aimed to create a new skylight prototype that is useful for several schools in the vicinity, since there is a lack of educational facilities. The former skylights consisted of plastic pyramids that presented serious disadvantages in terms of sustainability matters. During the design process, the priority changed to studying the factors that correlate daylighting with energy and other environmental aspects in a holistic and evocative approach. Accordingly, the new skylight features promote the admittance and di usion of solar energy through adroit guidance systems. In order to simulate di erent scenarios, we employed our own simulation tool, Diana X. This research-oriented software works with the e ects of direct solar energy that are mostly avoided in conventional programs. By virtue of Lambert’s reciprocity theorem, our procedure, which was based on innovative equations of radiative transfer, converts the energy received by di usive surfaces into luminous exitance for all types of architectural elements. Upon completion of the skylights, we recorded onsite measurements, which roughly coincided with the simulation data. Thus, conditions throughout the year improved

EFFECTS OF LOUVERS SHADING DEVICES ON VISUAL COMFORT AND ENERGY DEMAND OF AN OFFICE BUILDING. A CASE OF STUDY

This paper evaluates the building energy demand and visual comfort of a real case with a glazed façade office building placed in Málaga (Mediterranean city in the south of Spain). South oriented facades receive such a high solar gain that cooling demand cannot be handled by the current HVAC system. As an environmental friendly solution, a shading control strategy based on vertical and horizontal louvers is proposed. The study consists of a comparison between the actual and the refurbished building with shading devices. Daylighting simulation is done with Daysim (Daysim, 2016). A group of offices with south, east and north oriented facades is chosen for the study. Horizontal louvers in the south façade and vertical louvers in the east facade are modelled and simulated. The simulation changes the angle of the louver: 0º (perpendicular to the glazing), -30º, 30º, -60º, 60º. Visual comfort parameters analyzed are: illuminance, daylight autonomy (DA) and useful daylight index (UDI). With respect to the thermal comfort, not only louvers orientation try to provide solar protection for glazed areas in cooling period but also maximize solar gains in heating period. However, an excessive daylight could affect discomfort glare. Shading control strategy must provide the equilibrium between both aspects. Thermal demand is calculated with Trnsys (TRNSYS, 2016).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Daylight Spectrum Index: A New Metric to Assess the Affinity of Light Sources with Daylighting

The current scenario of colorimetry shows a wide variety of different metrics which do not converge in the assessment of the color rendering of light sources. The limitations of the Color Rendering Index have promoted the emergence of new metrics, such as the Color Quality Scale. As in the case of the previous metric, these new concepts are based on the analysis of the deviation of different color samples in a color space, contrasting the results with those obtained with a light source reference, which can vary depending on the color temperature. Within this context, the Daylight Spectrum Index is proposed. This new concept aims to determine the affinity with daylighting of electric light sources, comparing the resulting spectral power distributions of the lamps studied and that observed under natural light. The affinity of an electric light source with daylighting allows for lower energy consumption due to the better performance of human vision. The new metric proposed is evaluated following the results obtained from 80 surveys, demonstrating the usefulness of this new concept in the quantification of color rendering of LED lamps and the affinity of electric light sources with daylighting.Government of Spain BIA2017-86997-

Daylighting rule of thumb and typology

Rule of thumb in daylighting has been responsible for generating typologies of building forms and elements. However, not all of these typologies perform well in daylighting. This article briefly reviews the concept of typology in architecture and proposes its application in daylighting study. Based upon the literature and recent researches in daylighting typology, the authors argue for the use of typological approach as means for analyzing and generating rule of thumb in daylighting. Simulations are conducted using Lumen Micro 8 and AGi32 softwares. The findings are suggestive that the typological approach adapted in the simulations can contribute towards development of a new rule of thumb in daylighting