Comparison between PCM filled glass windows and absorbing gas filled windows

Abstract From the thermal point of view, windows represent the weak link between the internal and external ambients of a room. In cold climates, they are responsible for 10–25% of the heat lost from the heated ambient to the external atmosphere. In hot climates, the excessive solar radiation entering the internal ambient through the windows leads to increasing the cooling load of the refrigeration system. The use of absorbing gases filling the gap between glass sheets appears to be an alternative solution for thermally insulated glass windows. The other options one may incorporate filling materials such as silica aerogel or a PCM. In this work, a comparison between the thermal efficiency of two glass windows one filled with an absorbing gas and the other with a PCM and exposed to solar radiation in a hot climate is done. To model double glass window filled with infrared absorbing gases, a CW real gas model is used. A radiative convective conductive model and a radiative conductive model were investigated. Three mixtures of gases were used; a strongly absorbing gas mixture, an intermediate absorbing gas mixture and a transparent to infrared radiation mixture. To model the double glass window filled with a PCM, a relatively simple and effective radiation conduction one dimensional formulation is used. Heat transfer through the window is calculated and the total heat gain coefficients are compared and discussed.

[1]  H. Manz,et al.  TIM–PCM external wall system for solar space heating and daylighting , 1997 .

[2]  L. R. Mills,et al.  The benefits of using window shades , 1993 .

[3]  B. W. Webb,et al.  A Spectral Line-Based Weighted-Sum-of-Gray-Gases Model for Arbitrary RTE Solvers , 1993 .

[4]  Evyatar Erell,et al.  Controlling the transmission of radiant energy through windows: a novel ventilated reversible glazing system , 2000 .

[5]  Volker Wittwer,et al.  Some thermal and optical properties of a new transparent silica xerogel material with low density , 1993 .

[6]  Anouar Soufiani,et al.  Gas IR Radiative Properties: From Spectroscopic Data to Approximate Models , 1999 .

[7]  Manfred Lenzen,et al.  Long-term field tests of vacuum glazing , 1997 .

[8]  D. Arasteh,et al.  Energy performance of evacuated glazings in residential buildings , 1996 .

[9]  M. Pinar Mengüç,et al.  Thermal Radiation Heat Transfer , 2020 .

[10]  Adrian Bejan,et al.  Natural Convection in a Vertical Enclosure With Internal Permeable Screen , 1991 .

[11]  H. Manz,et al.  Numerical simulation of heat transfer by natural convection in cavities of facade elements , 2003 .

[12]  A local-spectrum correlated model for radiative transfer in non-uniform gas media , 2002 .

[13]  John L. Wright,et al.  A Correlation to Quantify Convective Heat Transfer Between Vertical Window Glazings , 1996 .

[14]  K. Ismail,et al.  Application of multidimensional scheme and the discrete ordinate method to radiative heat transfer in a two-dimensional enclosure with diffusely emitting and reflecting boundary walls , 2004 .

[15]  Richard Edward Collins,et al.  Current status of the science and technology of vacuum glazing , 1998 .

[16]  J. P. Hartnett,et al.  Advances in Heat Transfer , 2003 .

[17]  Arno Seeboth,et al.  Materials for intelligent sun protecting glazing , 2000 .

[18]  Carl M. Lampert,et al.  HEAT-MIRROR COATINGS FOR ENERGY-CONSERVING WINDOWS , 1981 .

[19]  K. H. Haddad,et al.  Comparison of the monthly thermal performance of a conventional window and a supply-air window , 1998 .

[20]  Jun Tanimoto,et al.  Simulation study on an air flow window system with an integrated roll screen , 1997 .

[21]  Kamal Abdel Radi Ismail,et al.  Thermally effective windows with moving phase change material curtains , 2001 .

[22]  Kamal Abdel Radi Ismail,et al.  U-values, optical and thermal coefficients of composite glass systems , 1998 .

[23]  Tariq Muneer,et al.  Combined conduction, convection, and radiation heat transfer model for double-glazed windows , 1997 .

[24]  K. Ismail,et al.  APPLICATION OF A LOCAL-SPECTRUM CORRELATED MODEL TO MODELING RADIATIVE TRANSFER IN A MIXTURE OF REAL GAS MEDIA IN BIDIMENSIONAL ENCLOSURES , 2004 .

[25]  Fred Landis,et al.  Numerical and Machine Solutions of Transient Heat-Conduction Problems Involving Melting or Freezing: Part I—Method of Analysis and Sample Solutions , 1959 .

[26]  T. S. Eriksson,et al.  Transparent Thermal Insulation With Infrared-Absorbing Gases , 1986, Other Conferences.

[27]  M. Sivrioglu,et al.  An experimental study on air window collector having a vertical blind for active solar heating , 1996 .

[28]  K. Ismail,et al.  APPLICATION OF THE CW MODEL FOR THE SOLUTION OF NON-GRAY COUPLED RADIATIVE CONDUCTIVE HEAT TRANSFER IN DOUBLE GLASS WINDOW WITH A CAVITY FILLED WITH MIXTURES OF ABSORBING GASES , 2004 .

[29]  Dariush Arasteh,et al.  The effects 3f infrared absorbing gasses on window heat transfer: A comparison of theory and experiment , 1990 .

[30]  Michael F. Modest,et al.  The Full-Spectrum Correlated-k Distribution for Thermal Radiation From Molecular Gas-Particulate Mixtures , 2002 .

[31]  Svend Svendsen,et al.  Monolithic silica aerogel in superinsulating glazings , 1998 .