48 research outputs found
Conservation compatible energy retrofit technologies:Part III: Documentation and assessment of materials and solutions for wall insulation in historic buildings
No full textThis report 1) describes basic aspects of the procedure and technical aspects of the energy retrofitting of historic walls, 2) contains the documentation of a wide variety of thermal refurbishment solutions for external walls, 3) contains an evaluation method for the renovation solutions for external walls. For this purpose, the assessment categories according to EN 16883 were taken as a basis and adapted in detail for walls
Dynamic thermal and hygrometric simulation of historical buildings: Critical factors and possible solutions
No full textBuilding dynamic simulation tools, traditionally used to study the hygrothermal performance of new buildings
during the preliminary design steps, have been recently adopted also in historical buildings, as a tool to investigate
possible strategies for their conservation and the suitability of energy retrofit scenarios, according to the
boundary conditions.
However, designers often face with the lack of reliable thermophysical input data for various envelope
components as well as with some intrinsic limitations in the simulation models, especially to describe the geometric
features and peculiarities of the heritage buildings. This paper attempts to bridge this knowledge gap,
providing critical factors and possible solutions to support hygrothermal simulations of historical buildings.
The information collected in the present work could be used by researchers, specialists and policy-makers
involved in the conservation of building’s heritage, who need to address a detailed study of the hygrothermal
performance of historical buildings thorugh dynamic simulation tools
Numerical analysis of ventilation temperatures regulation by energy storage in phase change materials
No full textInternational audienceIn order to cool a house using the freshness of the cold night air, Phase Change Materials (PCM) placed in an air heat exchanger coupled with a ventilation system have been investigated. The heat exchanger is composed of a number of units with horizontal PCM sheets contained in a box beam. Air is flown between the sheets from one side to the other and exchange heat with the material by convection. At night, fresh air is used to regenerate the PCM. To analyze the behavior of such a system in a retrofitted house with the climate of 3 different French cities, simulations in different configurations have been carried on. The TRNSYS software runs the model, coupled with Matlab for the model of the PCM / air heat exchanger. Results are expressed in terms of percentage of the time when the indoor temperature reaches each temperature and comparison between the different configurations
Numerical analysis of ventilation temperatures regulation by energy storage in phase change materials
No full textInternational audienceIn order to cool a house using the freshness of the cold night air, Phase Change Materials (PCM) placed in an air heat exchanger coupled with a ventilation system have been investigated. The heat exchanger is composed of a number of units with horizontal PCM sheets contained in a box beam. Air is flown between the sheets from one side to the other and exchange heat with the material by convection. At night, fresh air is used to regenerate the PCM. To analyze the behavior of such a system in a retrofitted house with the climate of 3 different French cities, simulations in different configurations have been carried on. The TRNSYS software runs the model, coupled with Matlab for the model of the PCM / air heat exchanger. Results are expressed in terms of percentage of the time when the indoor temperature reaches each temperature and comparison between the different configurations
Enhancement of PbZrO3 polarization using a Ti seed layer for energy storage application
No full textInternational audienceEnhancement of lead zirconate (PbZrO 3) polarization is achieved by using a titanium seed layer on alumina polycrystalline substrate. Thanks to the reduction of the lattice mismatch between the platinum electrode (3.92 Å) and the PbZrO 3 films (4.14 Å), lead zirconate thin films oriented along the (111) direction with an orientation factor of around 65 % has been obtained. The (111) PbZrO 3 presents an increase of 56 % of the polarization compared to the (100) PbZrO 3. This enhancement is responsible of the higher recoverable energy storage density obtained in the (111) PbZrO 3 thin films (8 J/cm 3 at 600 kV/cm with an efficiency of 72 %). The (111) PbZrO 3 also has a higher figure of merit, which indicates that the (111) crystallographic plane is the most favorable direction for energy storage
First evidence of resistive switching in polycrystalline GaV4S8 thin layers
No full textRecently a new type of reversible and non-volatile resistive
switching was discovered in single crystals of Mott insulators AM4X8 (A = Ga, Ge; M = V, Nb, Ta; X = S, Se). Here we report on the first synthesis of thin layers (thicknesses in the 100 to 1000 nm range) of GaV4S8 by RF magnetron sputtering process. Energy dispersive spectroscopy, X-ray diffraction and TEM analyses attest the high quality of polycrystalline GaV4S8 thin layers. Electrical measurements demonstrate that deposited GaV4S8 thin films exhibit a non-volatile reversible resistive switching at room temperature with writing/erasing times of ~10 μs and a memory window (Rhigh – Rlow)/ Rlow > 33%
Investigation of post-insulated walls with wooden beam ends [Elektronisk resurs] : Risk analysis for different insulation techniques
No full textInvestigation of post-insulated walls with wooden beam ends : Risk analysis for different insulation techniques
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