Sky vault partition for computing daylight availability and shortwave energy budget on an urban scale

Beckers, Benoît; Beckers, Pierre

doi:10.1177/1477153513502507

Cited by 15 publications

(4 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The first step for computing long‐wave radiation consists in meshing the sky vault using the same kind of partition than for short‐wave [BB14] but with 230 elements instead of 2400. Fewer elements are enough because the distribution of long‐wave sky radiances is smoother than short‐wave ones.…”

Section: Methodsmentioning

confidence: 99%

“…As proposed in [ANGN*19], the Liu and Jordan clear sky model [LJ60] is used to estimate the direct and diffuse sky emissions, taking the measured global horizontal irradiances as input. A sky vault partition [BB14] with 2400 tiles is used to account for the anisotropy of the emission. The radiance value for each tile is calculated with Perez all‐weather sky model [PSM93].…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Physically Based Simulation and Rendering of Urban Thermography

Aguerre

García‐Nevado

Miño

et al. 2020

Computer Graphics Forum

View full text Add to dashboard Cite

Urban thermography is a non‐invasive measurement technique commonly used for building diagnosis and energy efficiency evaluation. The physical interpretation of thermal images is a challenging task because they do not necessarily depict the real temperature of the surfaces, but one estimated from the measured incoming radiation. In this sense, the computational rendering of a thermal image can be useful to understand the results captured in a measurement campaign. The computer graphics community has proposed techniques for light rendering that are used for its thermal counterpart. In this work, a physically based simulation methodology based on a combination of the finite element method (FEM) and ray tracing is presented. The proposed methods were tested using a highly detailed urban geometry. Directional emissivity models, glossy reflectivity functions and importance sampling were used to render thermal images. The simulation results were compared with a set of measured thermograms, showing good agreement between them.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Physically Based Simulation and Rendering of Urban Thermography

Aguerre

García‐Nevado

Miño

et al. 2020

Computer Graphics Forum

View full text Add to dashboard Cite

show abstract

“…The temperature of each tile is taken from the pixel the closest to its center. We use the partition scheme described by Beckers (2014), which allows us to freely choose the number of tiles and ensures that each of them has the same solid angle and aspect ratio. Doing so, the maximum angular displacement between the center of a tile and its boundary is nearly constant and controlled.…”

Section: Methodsmentioning

confidence: 99%

Exploring The Sky Longwave Radiance Distribution In The French Basque Country

Nahon¹,

Miño²,

Beckers³

Building Simulation Conference Proceedings

View full text Add to dashboard Cite

The atmospheric radiation has a significant impact on the outside surface temperatures, and so on the building heating and cooling loads and on the outdoor thermal comfort. It is considered isotropic in most of the thermal simulation programs, though sky thermography shows that it is strongly anisotropic in the absence of clouds, with a gradient from the zenith to the horizon. The main objective of this work is to propose a model for the sky temperature distribution under all-weather. Its originality is to propose thermograms of the complete sky vault under typical weather conditions. The observed sky temperature distributions are compared to the results of the models by Bliss (1961) and Martin and Berdhal (1984a). The latter allowed for a correlation coefficient higher than 92% for five of the six analyzed sky conditions. The comparison between the radiant power absorbed by a vertical surface at the Earth level using this model or considering an isothermal sky shows differences of up to 16%, resulting in differences of up to 3.5°C in the mean radiant temperature.

show abstract

“…To build a 4𝜋 thermogram, it is necessary to use a spherical canvas. The hemisphere partition proposed by Beckers (2014a) was used in this study. It allows the user to select the number of cells while ensuring that each one retains the same solid angle and aspect ratio.…”

Section: Partition Of the Spherementioning

confidence: 99%

4π Thermograms : A ProjectionTo Understand Thermal Balance

Miño¹,

Lawrence²,

Beckers³

Building Simulation Conference Proceedings

View full text Add to dashboard Cite

The objective of this work is to represent in a compact and synthetic way surface temperatures at different points of interest throughout an urban scene, by building 4π Thermograms. From a geometrical approach, combining thermography and photographic techniques, a panoramic thermogram is assembled, which enables all directions to be seen from one position. This spherical representation of the data permits to observe the radiative phenomena in a spatialized way allowing its quantification and better understanding. Spatialized distribution of radiation could be expressed as an average temperature weighted by the area of all objects surrounding the measuring point. This emerges as an interesting alternative for measuring the mean radiant temperature in a complex urban scene where multiple heterogeneous surfaces must be considered.

show abstract

Sky vault partition for computing daylight availability and shortwave energy budget on an urban scale

Cited by 15 publications

References 14 publications

Physically Based Simulation and Rendering of Urban Thermography

Physically Based Simulation and Rendering of Urban Thermography

Exploring The Sky Longwave Radiance Distribution In The French Basque Country

4π Thermograms : A ProjectionTo Understand Thermal Balance

Contact Info

Product

Resources

About