A Human-Centered Approach for the Design of Perimeter Office Spaces Based on Visual Environment Criteria

With perimeter office spaces with large glazing facades being an indisputable trend in modern architecture, human comfort has been in the scope of Building science; the necessity to improve occupants’ satisfaction, along with maintaining sustainability has become apparent, as productivity and even the well-being of occupants are connected with maintaining a pleasant environment in the interior. While thermal comfort has been extensively studied, the satisfaction with the visual environment has still aspects that are either inadequately explained, or even entirely absent from literature. This Thesis investigated most aspects of the visual environment, including visual comfort, lighting energy performance through the utilization of daylight and connection to the outdoors, using experimental studies, simulation studies and human subjects’ based experiments

An Investigation of the Operational and Design Characteristics of Circadian Lighting Systems

This report investigates the operation of circadian lighting systems to gain an understanding of the main design and control characteristics and to promote different objectives for use. Research is guided by asking how color intensity, color temperature and their temporal characteristics are related to the circadian response, and how this knowledge can be utilized when designing and operating lighting systems for indoor environments. This report features an extensive literature review and case study application cut short by the impact of the novel coronavirus. Future investigation and implementation is encouraged

An Investigation of the Operational and Design Characteristics of Circadian Lighting Systems - Report

This report investigates the operation of circadian lighting systems to gain an understanding of the main design and control characteristics and to promote different objectives for use. Research is guided by asking how color intensity, color temperature and their temporal characteristics are related to the circadian response, and how this knowledge can be utilized when designing and operating lighting systems for indoor environments. This report consists of an extensive literature review and case study application cut short by the impact of the novel coronavirus. The case study takes place in an office space housed on the UNMC campus featuring an installed circadian lighting system capable of changing color temperature and intensity independently. The results of the literature review lead to the understanding of biological impacts of suggested operational patterns for the lighting system. Specifically, the interaction between human physical characteristics as they relate to the current lighting technologies has helped to develop the rational for use of these systems. These biological impacts ultimately aim towards improved occupant attention and well-being in the space. Future investigation and implementation are encouraged to continue advanced analysis of occupant response to varied patterns of operation for this circadian lighting system

Daylight Glare Probability Measurements And Correlation With Indoor Illuminances In A Full-Scale Office With Dynamic Shading Controls

Daylight glare evaluation has been the recent focus of research on visual comfort since newer office buildings have large glass facades offering daylight provision and outdoor views. Available glare indices are related to source luminance size and location, view direction and background luminance. The Daylight Glare Probability index that considers vertical illuminance at the eye level, has been identified as one of the reliable metrics, since it was based on experiments with real human subjects. In this study, extensive experiments were conducted in a full-scale private office environment with dynamic shading controls, to measure interior luminance and illuminance conditions under variable sky conditions and shading control strategies. A high dynamic range camera with a fish eye lens was used to capture the luminance in the field of view, while horizontal and vertical illuminance was measured at different positions. The images were processed for calculating DGP values based on the “evalglare” method. The results are used to evaluate the efficiency of control strategies in terms of glare probability, while correlations between indoor illuminances, sky conditions and DGP may lead to simplified criteria and guidelines for controlling daylight glare in office spaces. Finally, the experimental results can be used for a daylight model validation for spaces with dynamic facades

A New Control Framework For The Visual Environment Based On Low-Cost HDR Luminance Acquisition

This study introduces a new control framework, based on a low-cost programmable luminance acquisition (HDR) sensor placed on the interior surface of the window. The new sensor, photometrically and geometrically calibrated, can capture luminance and geometry details of potential glare sources within its entire visual span in real time, while also providing feedback about transmitted illuminance. Real-time processing of the sensor data enables an alternate, low-cost glare sensing system that can be directly used in daylighting controls and building automation systems. This novel framework is the first proposed solution to address direct and reflective glare in a straightforward and efficient way and therefore it is a significant step towards improving the visual environment in perimeter building zones

The Effects of the Visual Environment on K-12 Student Achievement

The varying indoor environments among educational buildings can have an impact on students’ ability to learn. This study looks at field data from 220 classrooms in the Midwest, United States, over a two-year period, to analyze the effects of the visual environment on student achievement. The visual environmental metrics considered within this scope include the three new view metrics introduced within the EN 17037 “Daylight of Buildings” standard (Horizontal Sight Angle, Outside Distance of View, and Number of View Layers), as well as standard daylight and electric lighting metrics, focusing on light availability and glare. To capture student achievement, math and reading achievement scores were used, accompanied by auxiliary demographic variables. This allowed for a correlational analysis using multivariate regression. Among the notable results of this study, there was a positive effect of the availability of view on reading achievement. However, another view metric, Horizontal Sight Angle, showed a significant negative interaction with free and reduced lunch recipients on reading achievement, indicating that demographics can also have a significant role in the way the visual environment can affect learning

A New Interactive Web-based Tool to Evaluate The Efficiency of Solar Protection Devices

This presentation will be a demo of a new intractive tool and a web-based interactive graphical user interface for estimating the potential cooling energy savings with exterior solar protection devices and interior light-shelves. The modeling tool takes into account relevant parameters and allows the user to input basic information about the size of the building, size of exterior facades and windows, and glazing and framing optical and thermal properties. The user can then select among a variety of exterior solar protection devices (e.g., horizontal louvers, vertical blades, etc) of different shapes, tilt angles and dimensions, and place them on different locations on the façade. Other options include interior light-shelves and louvers with integrated PV panels. The tool reads climatic information from a TMY3 database and performs a thermal analysis of the space using a simplified heat balance method, as well as a lighting analysis when light-shelves are selected. The analysis runs real-time in a few seconds and provides the potential cooling energy savings and lighting benefits with the selected shading systems. The users can easily compare between different shading solutions and geometries on a relative basis. The reliability of data exchange and the practical, user-friendly web interface are major advantages of the new interactive tool

Daylight Glare Evaluation When the Sun is Within the Field of View Through Window Shades

Shading fabrics have the ability to reduce daylight glare and provide privacy when needed. Recent studies have shown that glare indices such as DGP and its simplified version can be used to predict daylight glare through shades when the sun is not within the field of view. However, there are no comprehensive studies on glare sensation with the sun visible through the fabric – a situation that happens in office buildings – and therefore the applicability of glare indices for such conditions is uncertain. Shades with very low openness factors transmit only a small amount of direct sunlight due to their weave density; nevertheless, existing glare metrics may show intolerable conditions for these cases, while specific studies with human subjects are nearly non-existent. This paper presents an experimental study on daylight glare evaluation for the case of shading fabrics with the sun within the field of view. 41 human subjects (n=41) were tested while performing specific office activities, with 14 shade products of different openness factors and visible transmittance values (direct and total light transmission characteristics). The measured variables and survey results were used to: (i) associate discomfort glare with measured and modeled parameters for these cases (ii) evaluate the robustness of existing glare indices for these cases (iii) examine recently suggested alternate (direct and total vertical illuminance) criteria for glare assessment through fabrics, extract discomfort thresholds and suggest a new related index and (iv) propose corrections in the DGP equation when the sun is visible through the shades, which could be generalized for other systems following a similar approach. Combining illuminance-based metrics and existing glare indices can result in a more realistic glare evaluation covering all cases with and without the sun through shading fabrics. The new results can be inversely used as thresholds for selecting optical properties of shades to ensure glare protection, as well as for the development of glare-based shading controls.