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Journal ArticleDOI

Theoretical analysis of the thermal performance of chemically deposited solar control coatings

14 Aug 1993-Journal of Physics D (IOP Publishing)-Vol. 26, Iss: 8, pp 1304-1309
TL;DR: In this paper, a mathematical model to predict the shading coefficients (SC) and solar rejection factor (SRF) of various types of chemically deposited solar control coatings is presented, and the values of SC and SRF are presented for coatings with soar absorptance in the 50-75% range and solar reflectance in a 10-25% range for typical exterior temperature of 10-50 degrees C.
Abstract: A mathematical model to predict the shading coefficients (SC) and solar rejection factor (SRF) of various types of chemically deposited solar control coatings is presented. The values of SC and SRF are presented for coatings with soar absorptance in the 50-75% range and solar reflectance in the 10-25% range for typical exterior temperature of 10-50 degrees C. Chemically deposited solar control coatings with a protective polymer coating applied on 6 mm thick sheet glass in architectural windows are seen to provide SC in the 0.3 to 0.75 range depending on the optical characteristics and exterior temperatures. A solar rejection factor of 33-56% is available from the coatings already reported.
Citations
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Journal ArticleDOI
TL;DR: In this article, the authors discuss the next generation of smart windows based on organic materials which can change their properties by reflecting or transmitting excess solar energy (infrared radiation) in such a way that comfortable indoor temperatures can be maintained throughout the year.
Abstract: Windows are vital elements in the built environment that have a large impact on the energy consumption in indoor spaces, affecting heating and cooling and artificial lighting requirements. Moreover, they play an important role in sustaining human health and well-being. In this review, we discuss the next generation of smart windows based on organic materials which can change their properties by reflecting or transmitting excess solar energy (infrared radiation) in such a way that comfortable indoor temperatures can be maintained throughout the year. Moreover, we place emphasis on windows that maintain transparency in the visible region so that additional energy is not required to retain natural illumination. We discuss a number of ways to fabricate windows which remain as permanent infrared control elements throughout the year as well as windows which can alter transmission properties in presence of external stimuli like electric fields, temperature and incident light intensity. We also show the potential impact of these windows on energy saving in different climate conditions.

877 citations

Journal ArticleDOI
TL;DR: In this article, the basic concepts underlying the chemical bath deposition technique and recipes developed in our laboratory during the past ten years for the deposition of good-quality thin films of CdS, CdSe, ZnS, PbSe, SnS, Bi2S3, BiSe3, SbS3 Sb2S2, CuS, CuSe, etc.

345 citations

Journal Article
TL;DR: In this article, an improved understanding of the impact of windows on thermal comfort and an analytical method for evaluating this impact was proposed, which could form the basis for a future NFRC window comfort rating method that could be used by designers and consumers.
Abstract: Anyone who has ever sat near a cold window on a winter day or in direct sunlight on a hot day recognizes that windows can cause thermal discomfort. In spite of this broad recognition there is no standard method to quantify the extent of such discomfort. The purpose of this study was to: 1. Review the literature to identify relevant work relating to windows and thermal comfort. 2. Develop an improved understanding of the impact of windows on thermal comfort and to propose an analytical method for evaluating this impact. The method could form the basis for a future NFRC window comfort rating method that could be used by both designers and consumers.

139 citations

Journal ArticleDOI
TL;DR: In this article, the formation of the ternary compound Cu3BiS3 (Wittichenite, JCPDS 9-488) during annealing of chemically deposited CuS (∼0.3 μm) films on Bi2S3 film on glass substrate is reported.
Abstract: Formation of the ternary compound Cu3BiS3 during annealing of chemically deposited CuS (∼0.3 μm) films on Bi2S3 film (∼0.1 μm on glass substrate) is reported. The interfacial atomic diffusion leading to the formation of the compound during the annealing is indicated in x-ray photoelectron depth profile spectra of the films. The formation of Cu3BiS3 (Wittichenite, JCPDS 9-488) is confirmed by the x-ray diffraction (XRD) patterns. The films are optically absorbing in the entire visible region (absorption coefficient 4 × 104 cm−1 at 2.48 eV or 0.50 μm) and are p-type with electrical conductivity of 102−103 Ω−1 cm−1. Potential applications of these films as optical coatings in the control of solar energy transmittance through glazings and as a p-type absorber film in solar cell structures are indicated.

67 citations

Journal ArticleDOI
TL;DR: In this article, a numerical study in a double-pane window with solar control film (SCF) for both warm and cold climates is presented, where the effect of varying the separation distance between the glasses, room temperature and the incident solar radiation is analyzed.

50 citations

References
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31 Dec 1990
TL;DR: A broad coverage of large-area chromogenics and their applications is given in this paper, which is divided into the following areas: applications; photochromic materials, thermochromic materials; inorganic electrochromic material, organic electro chromic materials and liquid crystals materials and devices.
Abstract: Chromogenic materials can alter their optical properties in a persistent yet reversible manner when subjected to a change in external conditions such as irradiation intensity, temperature, or electric-field strength. In the future chromogenic materials may be used on large scale to regulate the throughput of radiant energy for windows in buildings and cars, so that comfortable lighting and temperature are maintained without excessive air conditioning. The purpose of this book is to give a broad coverage of large-area chromogenics and to discuss their applications. The book is divided into the following areas: applications; photochromic materials; thermochromic materials; inorganic electrochromic materials; inorganic electrochromic materials; organic electrochromic materials; conductors for ions and electrons in electrochromic devices; electrochromic devices; and liquid crystals materials and devices. Separate abstracts were prepared for 33 papers in this book.

276 citations

Proceedings ArticleDOI
01 Mar 1990
TL;DR: A broad coverage of large-area chromogenics and their applications is given in this paper, which is divided into the following areas: applications; photochromic materials, thermochromic materials; inorganic electrochromic material, organic electro chromic materials and liquid crystals materials and devices.
Abstract: Chromogenic materials can alter their optical properties in a persistent yet reversible manner when subjected to a change in external conditions such as irradiation intensity, temperature, or electric-field strength. In the future chromogenic materials may be used on large scale to regulate the throughput of radiant energy for windows in buildings and cars, so that comfortable lighting and temperature are maintained without excessive air conditioning. The purpose of this book is to give a broad coverage of large-area chromogenics and to discuss their applications. The book is divided into the following areas: applications; photochromic materials; thermochromic materials; inorganic electrochromic materials; inorganic electrochromic materials; organic electrochromic materials; conductors for ions and electrons in electrochromic devices; electrochromic devices; and liquid crystals materials and devices. Separate abstracts were prepared for 33 papers in this book.

270 citations

Journal ArticleDOI
TL;DR: In this paper, the basic requirements of solar control coatings are presented and a comparison of the characteristics of PbS and CuxS coatings against commercially available coatings is provided.
Abstract: Solar control coatings, required for architectural glazing applications in warm climates, must provide controlled optical transmission ( approximately 10-50%) of the solar radiation in the visible region and should reflect efficiently in the infrared (>0.7 mu m) region to create a cool interior in the buildings. Thin films of PbS and CuxS on glass substrates, deposited from chemical baths, are shown to possess excellent solar control characteristics-superior or comparable to the metallic solar control coatings. For example, for an acceptable range of integrated optical transmittance ( approximately 10-20%) in the visible region, the integrated infrared reflectance for AM2 solar spectrum for the different glazings are: PbS coated glass, 50%; CuxS coated glass, 14%; stainless steel/Cu coated glass, 25% and tinted glass, 4%. The CuxS and PbS coatings also have the advantage of giving pleasant reflected colours (golden, purple, blue, etc), which improves the cosmetic appearance. This paper presents the basic requirements of solar control coatings and provides a comparison of the characteristics of PbS and CuxS coatings against commercially available coatings.

138 citations

Journal ArticleDOI
TL;DR: In this paper, the safety and cost and the optimisation of chemically deposited PbS thin films for solar control applications are presented. But the results of the analysis are limited to the case of 3 mm thick clear glass with a shading coefficient of approximately 50%.
Abstract: Assessments of safety and cost and the optimisation of chemically deposited PbS thin films for solar control applications are presented. The maximum integrated infrared reflectance, 44%, is obtained at a PbS thin film thickness of approximately=95 nm. The corresponding value of the solar control parameters (AM2 case) are: integrated infrared transmittance, 45%; integrated visible transmittance, 17% (yellowish appearance); integrated visible reflectance, 21% (purple appearance); and integrated solar absorptance, 36%. The total solar radiation and heat transfer into the building through a glazing with such a PbS coating is less than 44%, as compared with the approximately=84% of 3 mm thick clear glass, giving a shading coefficient of approximately=50%. A film thickness of 95 nm is obtainable with a deposition time of 50 min from a bath (at 24 degrees C) containing Pb2+ ions and thiourea in the 1:3 molar ratio. However, molar ratios up to 1:5 may be employed, thereby enabling the reduction of deposition time to 35 min. Analyses of the safety and the cost of these coatings have shown excellent promise for their application as medium-efficiency low-cost solar control coatings appropriate for small-scale industrial and 'do-it-yourself' production of the coatings.

96 citations

Journal ArticleDOI
TL;DR: In this paper, CuxS thin films appropriate for use as solar control coatings for architectural glazing applications have been deposited from chemical baths constituted from copper(II) nitrate or chloride, NH3(aq), NaOH, triethanolamine and thiourea.
Abstract: CuxS thin films appropriate for use as solar control coatings for architectural glazing applications have been deposited from chemical baths constituted from copper(II) nitrate or chloride, NH3(aq), NaOH, triethanolamine and thiourea. At ambient temperature (25 degrees C), the duration of deposition ranges from 2 to 12 h, but at 50 degrees C, deposition can be considerably faster, from 1 h to 2 h 50 min. CuxS films deposited in this manner require air annealing at 150 degrees C for about 10 min, to reduce the integrated infrared transmittance, T*(IR), to about 10%. The corresponding integrated transmittance in the visible region, T*(vis), is about 30% and the integrated transmittance for AM2 solar spectra is about 20%. The optical transmittance spectra of the annealed films are peaked in the 0.55-0.575 mu m wavelength range, which provides a greenish yellow illumination inside the building under daylight, that corresponds to the peak in the spectral sensitivity curve of the human eye for photopic (daylight) vision. The reduction in sheet resistance of the CuxS films with the air annealing, from about M Omega Square Operator -1 to about 10-100 Omega Square Operator -1, ensures a low thermal emittance which is a requirement for high-efficiency solar control coatings. The issues involved in the optimization of the deposition conditions for large-area production of the coatings and the choice of protective polymer coatings are also discussed.

81 citations