We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies glazing, shading, other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual evaluations CFS, b) accurate renderings CFS despite loss spatial resolution associated with low-resolution BSDF datasets for...

(1995). Discomfort Glare from Sources of Nonuniform Luminance. Journal the Illuminating Engineering Society: Vol. 24, No. 2, pp. 73-85.

Abstract This study uses ray-tracing software to calculate the fluence distribution in ultraviolet germicidal irradiation devices with different surface reflectivities and lamp configurations. Of five validation cases considered, one incorporating anisotropic duct reflectivity wind-chill correction of output gave best agreement planar irradiance measurements (mean error –3%, standard deviation 9%). The was used as a validated design tool evaluate two typical in-duct (Cases 6 7). Four...

AbstractUltraviolet germicidal irradiation (UVGI) systems inactivate microorganisms indoors. Upper-room UVGI use wall- or ceiling-mounted fixtures to create an air disinfection zone above the occupied zone. The performance of upper-room varies with indoor airflow patterns induced by mechanical ventilation and thermal plumes from heat sources. Little information is available on effects strategies system for control viral aerosols in spaces. This study simulated characteristics office space...

This article presents a variety of different approaches to both model and assess the performance daylight-integrated electric lighting control systems. In these systems, output controlled zone is based on light sensor reading calibrated algorithm. Computer simulations can consider simulated illuminance data generated from system daylight delivery whose addressed using typical meteorological year (TMY) weather data. Photosensor signals operation system’s dimming algorithms are also included....

(1998). Visual Performance and Clarity under Electric Light Sources: Part II—Visual Clarity. Journal of the Illuminating Engineering Society: Vol. 27, No. 1, pp. 29-41.

(2000). A Comparison of Photosensor-Controlled Electronic Dimming Systems in a Small Office. Journal the Illuminating Engineering Society: Vol. 29, No. 1, pp. 66-80.

(1997). Analysis of Daylight Photocell Placement and View in a Small Office. Journal the Illuminating Engineering Society: Vol. 26, No. 2, pp. 150-160.

Conventional photosensor-based lighting control systems rely on an integrated photosensor signal that senses the overall illuminance within a space and is calibrated to address performance at specific critical task point. All surfaces field of view (FOV) influence this signal. This paper presents new method applies inexpensive image sensor as light sensing device in conjunction with computer graphics technique known High Dynamic Range imaging. A wide range levels can be evaluated using...

The 10th edition of the IES Lighting Handbook will contain a new illuminance determination procedure. This article frames these recommendations within an historical context and describes how they are responsive to modern aspects lighting practice. procedure: 1) has more categories with finer steps; 2) provides method for interpreting whether target value is minimum, average, or maximum; 3) includes uniformity targets; 4) permits activity levels be accounted in outdoor environments; 5)...

This paper reports on a computer modeling study to assess the performance of different photosensor-controlled diming systems in daylighted classroom space. The addresses photosensor spatial response functions, ceiling positions relative window wall and control algorithms. results show that each these features impacts overall performance. In particular, view has is inversely related its ability properly track daylight provided dim electric lighting system accordingly.

AbstractThis study analyzes the performance of daylight-responsive photosensor control in five different daylighted classrooms using advanced computer modeling (Radiance). The daylight configurations considered include windows, lightshelves, clerestories and skylights. electric lighting systems both direct indirect systems. Different positions field-of-view were applied to determine their impact on a system's ability properly track levels within each space.For classroom condition,...

The accuracy of daylighting simulations for the built environment strongly depends on modeling exterior surround. practice a space with flat ground surface little or no external architectural landscape elements, particularly early in design phase, is often applied. In this study, approach and number different levels detail surround were investigated by comparing real-life empirical measurements their corresponding simulation results. A total 13 views studied under 15 sky/seasonal conditions...

Some building energy codes now require the incorporation of daylight into buildings and automatic photosensor-controlled switching or dimming electric lighting system in areas that receive daylight. This paper describes enhancements to open-source Daysim analysis software permit users model a photosensor control as it will perform real space, considering directional sensitivity , its mounting position, space aperture geometry, window shading configuration; equipment zones; exterior...