Solar and visible optical properties of glazing systems with venetian blinds: Numerical, experimental and blind control study

Abstract The increasing use of glazed areas in the building envelope can lead to high solar gains and glare problems that can strongly impact the entire building energy consumption, peak loads and indoor comfort. An important and fundamental strategy in sustainable building design for controlling solar heat gains and daylighting through fenestration is the use of shading devices. Therefore, it is recommended to use detailed models that can accurately estimate the optical properties of the different types of shading devices (such as roller blinds and venetian blinds) and include their effects in the glazing system analysis. This paper describes a net radiation method for determining both solar and visible optical properties of glazing with shading devices, particularly venetian blinds. Some numerical results were compared with in situ experimental measurements carried out in an outdoor test cell. The experimental work included the measurement of illuminance and irradiance fluxes and the determination of the visible and solar transmission properties of the fenestration system. The agreement between numerical predictions and experimental results was better for overcast than clear sky conditions. Moreover, a venetian blind control strategy that blocks direct solar radiation, whilst enabling the transmission of diffuse radiation to indoors, is implemented.

[1]  P. Pfrommer,et al.  Solar radiation transport through slat-type blinds: a new model and its application for thermal simulation of buildings , 1996 .

[2]  Dagnachew Birru,et al.  An open-loop venetian blind control to avoid direct sunlight and enhance daylight utilization , 2012 .

[3]  Iso Tc,et al.  Thermal Performance of Windows, Doors and Shading Devices — Detailed Calculations , 2000 .

[4]  J. Alexandre Bogas,et al.  Numerical and experimental study of the optical properties of venetian blinds , 2012 .

[5]  John L. Wright,et al.  Methods for Calculating the Effective Longwave Radiative Properties of a Venetian Blind Layer , 2004 .

[6]  John L. Wright,et al.  Improving Load Calculations for Fenestration with Shading Devices , 2009 .

[7]  Svetlana Olbina,et al.  Daylighting and thermal performance of automated split-controlled blinds , 2012 .

[8]  J. H. Klems.  A New Method for Predicting the Solar Heat Gain of Complex Fenestration Systems I. Overview and Derivation of the Matrix Layer Calculation , 1993 .

[9]  Andreas K. Athienitis,et al.  Thermal Analysis and Design of Passive Solar Buildings , 2000 .

[10]  A. Athienitis,et al.  The impact of shading design and control on building cooling and lighting demand , 2007 .

[11]  John L. Wright,et al.  Solar Gain through Windows with Shading Devices: Simulation Versus Measurement , 2009 .

[12]  Refrigerating.  ASHRAE handbook of fundamentals , 1967 .

[13]  John L. Wright,et al.  A Simplified Method for Calculating the Effective Solar Optical Properties of a Venetian Blind Layer for Building Energy Simulation , 2009 .

[14]  J. Klems.  A new method for predicting the solar heat gain of complex fenestration systems: II, Detailed description of the matrix layer calculation , 1993 .

[15]  John L. Wright,et al.  Methods for Calculating the Effective Solar-Optical Properties of a Venetian Blind Layer , 2005 .

[16]  Kwang Ho Lee,et al.  Automated control strategies of inside slat-type blind considering visual comfort and building energy performance , 2012 .

[17]  J. Rosenfeld,et al.  Optical and thermal performance of glazing with integral venetian blinds , 2001 .

[18]  Myoung Souk Yeo,et al.  Automated blind control to maximize the benefits of daylight in buildings , 2010 .

[19]  Chanvit Chantrasrisalai,et al.  An In Situ Experimental Method for the Development and Validation of Slat-Type Blind Models in Cooling Load Calculations , 2006 .

[20]  H. Manz,et al.  Energy performance of glazings in European climates , 2012 .

[21]  D. Edwards.  Solar absorption by each element in an absorber-coverglass array , 1977 .

[22]  Athanasios Tzempelikos,et al.  A hybrid ray-tracing and radiosity method for calculating radiation transport and illuminance distribution in spaces with venetian blinds , 2012 .

[23]  S. Rheault,et al.  Heat transfer analysis in an automated venetian blind window system , 1989 .

[24]  Joseph H. Klems.  Solar Heat Gain Through Fenestration Systems Containing Shading: Procedures for Estimating Performance from Minimal Data , 2000 .

[25]  John L. Wright,et al.  Solar Absorption by Each Element in a Glazing/Shading Layer Array , 2006 .

[26]  Jia Hu,et al.  Illuminance-based slat angle selection model for automated control of split blinds , 2011 .

[27]  Myoung-Souk Yeo,et al.  An experimental study on the environmental performance of the automated blind in summer , 2009 .

[28]  T. Talmatamar,et al.  Analysis of solar radiation for sunlit glass shaded by vertical adjustable flat slats , 1995 .

[29]  H.A.L. van Dijk,et al.  Modelling the optical and thermal properties of complex glazing: overview of recent developments , 2001 .

[30]  Athanassios Tzempelikos,et al.  The impact of venetian blind geometry and tilt angle on view, direct light transmission and interior illuminance , 2008 .