Adaptive Thermochromic Energy Saving Glazing of Buildings
Tech Area / Field
- CHE-POL/Polymer Chemistry/Chemistry
- MAT-SYN/Materials Synthesis and Processing/Materials
3 Approved without Funding
Vavilov State Optical Institute (GOI) / Research and Technological Institute of Optical Materials, Russia, St Petersburg
- State Educational Institution of the Highest Professional Education “Saint Petersburg State Technological University of Plant Polymers”, Russia, St Petersburg
- Fraunhofer Institut Angewandte Polymerforschung, Germany, Potsdam\nInterpane. Entwicklungs- und Beratungsgesellschaft mbH, Germany, Lauenförde
Project summaryActuality. The threat of global economic and ecological crisis caused by the drastic growth of energy consumption and, as a consequence, the increase in cost of hydrocarbon fuel and emission of greenhouse gases into atmosphere require maximal usage of natural energy sources of heat and light. Nowadays, not only windows but also walls with special glazing (structural glazing) can be realized as a multi functional, even “smart”, system ensuring energy-saving and comfortable conditions for human living.
It is well known, that heating and conditioning of buildings both in Europe and in the US consume 45-50% of all produced energy and are responsible for the emission of more than 30% of greenhouse gases into atmosphere. Meanwhile, 60% of energy received by a building is irreversibly lost due to the emission through windows by convection (9%), heat conduction (9%) and infrared (Plank) radiation (42%) mechanisms. Usage of glass units optimized by thickness and filled with argon or krypton makes it possible to reduce the losses of the first two types while the problem of the reduction of main energy losses, that is infrared (IR) radiation losses achieving 150 W/sq.m at 30oC inside – outside temperature difference, remains unsolved. These losses are the flux of heat, which flows out of the room in winter and into the room, on the contrary, in summer that causes the necessity of its conditioning which is 5-10 times more expensive than heating.
Commercial products based on the usage of both “passive”, which is with constant light transmittance, and “active” materials, the optical transmittance of which varies under the influence of external factors, are well known. “Passive” glasses include tinted and low-emissivity (low-E) glasses. Disadvantage of tinted glasses proceeds from the fact that in winter their usage leads to insufficient illumination and impossibility to use solar energy for heating. Disadvantage of low-E glasses is that their high optical transmittance in the visible spectral range causes overheating of buildings in summer.
Physical phenomena used in “active” glasses lead to variation of optical transmittance due to the growth of absorption or scattering under the impact of daylight or electric field on the glass itself or the substance inserted between two window panes (triplex). Satisfactory solution has not been found up to now because glasses of this type are found to be operationally unstable, chemically non-resistant, and too expensive.
Novelty of the Project comes from research and development of adaptive energy saving thermochromic triplex (AdaTriplex) assembled from two window glass panes with a thermochromic film between them adaptable to external conditions and prepared from a polymer doped with metal complexes. Alteration of polymer temperature induces the change of complex coordination that causes reversible variation of optical radiation transmittance that can lead to the variation of AdaTriplex color. Assembling of a double pane insulated glass unit from offered “active” AdaTriplex and commercially produced “passive” low-E glasses allows to manufacture an adaptive energy saving glass unit (AdaGlass Unit) in order to control daylight transmittance and radiative heat exchange between a building and environment. The latter makes it possible to eliminate the disadvantages of modern glazing types listed above and to supply commercially produced noise protective and safety glass units with the additional property – energy saving.
Goal of the Project: designing AdaTriplex and energy saving AdaGlass Unit controlling daylight transmittance and radiative heat exchange between buildings and environment that includes elaboration of polymer composition containing thermochromic agents, technology of coating a glass with polymeric compound followed by its sealing (laminating), and technology of assembling AdaGlass Unit from AdaTriplex and commercial low-E glass.
Preliminary experience of applicants. Applicants, that is the research team consisting of weapon scientists of Research and Technological Institute of Optical Material Science of All-Russian Scientific Center “S.I. Vavilov State Optical Institute” and Military Engineering Technical University and the research team including scientists of Saint Petersburg State Technological University of Plant Polymers and Saint Petersburg State University have been engaged in research and development of optical materials on the base of organic and inorganic glassy substances for over 30 years. The applicants plan to use results of their studies performed under completed ISTC projects #979, #2428, #2696 in 1998-2007. Scientific leadership will be performed by Prof. O. Yanush who is author of the idea of adaptive thermochromic energy saving glazing. Dr. L.Maksimov who has 9 year experience of ISTC projects management is supposed to be manager of the proposed Project.
Scientific results: scientific basis for manufacturing of AdaTriplex with various coloring (neutral, grey, brown, blue, green, etc.) and enhanced thermochromic response to variation of temperature and daylight intensity, new chemical methods to increase solubility of chemical reagents in polymer hosts, theoretical and experimental results of the analysis of heat flows inside a building and thermophysical parameters of AdaTriplex and AdaGlass Unit, allowing to estimate energy saving in the process of exploitation of buildings located in various climatic zones of Europe for the glazing of which AdaTriplexes and /or AdaGlass Units were used.
Technical results: new compositions and energy saving technologies of AdaTriplexes manufacturing, in particular, the process of thermochromic film lamination in autoclave at reduced temperature (not exceeding 100oC) and 1 bar pressure, inexpensive technology of AdaTriplex manufacturing using thermochromic photocurable compositions.
Commercial results: novel products ensuring energy saving in process of exploitation of buildings located in different climatic zones of Europe, i.e. a series of AdaTriplexes and AdaGlass Units controlling daylight transmittance and radiative heat exchange between a building and environment, and laboratory technology of their manufacturing.
Areas of applications: energy saving office, trade, and public buildings, inpidual “zero net energy” houses, structural glazing of buildings, glazing of greenhouses and hotbeds, designing interiors with decorative panels of variable coloring (chameleon).
Future sustainable development is determined by good prospect for commercialization of the project results that includes starting-up own business due to the existence of potential demand on the part of manufacturers of architectural glass, mainly, double pane insulated glass units with low-E coating, the production of which should achieve 200-300 hundred million sq. meters in 2009 and by the uniqueness of the Project results that allow to solve the problem of energy saving through the glazing of buildings.
In accordance with preliminary estimations, the application of AdaGlass Units will make it possible to reduce the heat flow into the building in the latitude of Brussels in summer by not less than 40% that will let compensate costs of purchasing and assembling these units within 1 year due to the reduction of the cost of conditioning. Usage of luminescent dopants will extend the area of application of the glazing to the decoration of interiors of inpidual houses and public buildings.
Meeting ISTC Goals and Objectives. Fulfillment of the Project will promote achieving the goals of the ISTC because Russian weapon scientists will have a chance to redirect their activity to peaceful studies in the field of environment protection and energy saving and to transfer their innovation activity to self financing, as well; facilitate the integration of Russian scientists into international scientific community, serve to stimulate the transforming of Russian economy into the free market oriented economy.
The Project is an extended applied experimental investigation in physical chemistry, chemistry and technology of organic and inorganic glassy materials. The Project includes experimental and theoretical study of the influence of amorphous host composition and its structure on absorption and luminescence spectra of transition and rare-earth metals, study of the influence of amorphous host compositions and their structure on thermochromic properties of transition metal complexes in them, compatibility of trial samples of thermochromic substances with commercial vinyl based polymers, possibility of plasticizing of vinyl based polymers with protonic and aprotic solvents, compatibility of trial samples of thermochromic agents with photocurable resins applied to manufacturing of laminated glasses (triplexes), improvement of decorative parameters of AdaTriplexes due to doping with luminescent ions.
Technical approach and methodology are based on usage of computer simulations of electrolyte models of solutions and phase equilibrium for the calculation of reaction equilibrium constants. The applicants propose to develop theory of forming practically important structures of complexes and polymeric materials, theoretical model of intra molecular catalysis with a charge transfer and participation of transition metal complexes, as well as theoretical description of thermophysical processes occurring in AdaTriplexes and AdaGlass Units. The applicants suggest applying structural sensitive spectral optical methods to optimization of composition and structure of components of AdaTriplex. The applicants plan to elaborate and manufacture trial samples of AdaTriplexes and AdaGlass Units, perform tests, determine operation parameters, estimate efficiency of AdaGlass Units in the process of exploitation of buildings in various climatic zones of Europe.
Collaboration with foreign specialists will include information exchange, discussion of current Project results, and transfer of samples to collaborators’ laboratories for testing. On the base of independent test results, commercial future of novel product on the architectural glass market will be estimated. The applicants will analyze the possibility of using the novel product for inpidual “zero net energy houses”. To reduce the cost of transferring laboratory technology to industry, the applicants plan to adapt the technological process to commercial technological lines for triplex production.
Social consequences of the Project implementation result from the appearance of product enhancing the shrinkage of dependence of economy of industrial countries on irrecoverable energy sources and counteracting climatic change caused by the exhaustion of greenhouse gases into the atmosphere.