Browsing by Keyword "Energy simulation"
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Item Comparison between Energy Simulation and Monitoring Data in an Office Building(2021-12-30) Martin-Escudero, Koldobika; Atxalandabaso, Garazi; Erkoreka, Aitor; Uriarte, Amaia; Porta, Matteo; EDIFICACIÓN DE ENERGÍA POSITIVA; Tecnalia Research & InnovationOne of the most important steps in the retrofitting process of a building is to understand its pre-retrofitting stage energy performance. The best choice for carrying this out is by means of a calibrated building energy simulation (BES) model. Then, the testing of different retrofitting solutions in the validated model allows for quantifying the improvements that may be obtained, in order to choose the most suitable solution. In this work, based on the available detailed building drawings, constructive details, building operational data and the data sets obtained on a minute basis (for a whole year) from a dedicated energy monitoring system, the calibration of an in-use office building energy model has been carried out. It has been possible to construct a detailed white box model based on Design Builder software. Then, comparing the model output for indoor air temperature, lighting consumption and heating consumption against the monitored data, some of the building envelope parameters and inner building inertia of the model were fine tuned to obtain fits fulfilling the ASHRAE criteria. Problems found during this fitting process and how they are solved are explained in detail. The model calibration is firstly performed on an hourly basis for a typical winter and summer week; then, the whole year results of the simulation are compared against the monitored data. The results show a good agreement for indoor temperature, lighting and heating consumption compared with the ASHRAE criteria for the mean bias error (MBE).Item Optical model for multilayer glazing systems: Application to laminated glass and photovoltaic modules: Application to laminated glass and photovoltaic modules(2016-02-01) Baenas, Tomás; Machado, Maider; Tecnalia Research & InnovationThis article provides theoretical developments broadening the scope of previous optical simulation models for multilayer glazing systems. The applicability of existing models will be extended through additional characterization of the multilayer optical components from global spectrophotometric (UV–vis–NIR) measurements. A more complete interlayer film characterization, including reflectivity in the film–glass interface, will be provided. Singular solutions of the related equation systems will be derived for situations involving components with very low or null transmissivity. As a contribution to the fundamentals of the formalism, the condition relating the symmetry of the transmittance of the system with the symmetry of the transmissivity of its optical components will be studied. Finally, with the extension for the calculation of energy fluxes through the components of a multilayer system, analytical expressions for the components absorptivity will be derived. These results are particularly useful to quantify differences in energy absorption of the constituents of a laminated glass, as a tool to define, from the glazing design phase, the thermal and mechanical processing needed for each glazing component. Additionally, the model provides a procedure for the calculation of the absorptivity of encapsulated photovoltaic cells, which is directly related to cell efficiency in each particular configuration.Item A simulation-based assessment of humidity treatment in data centre cooling systems with air-side economisers(2018) Rachman, Arinda Puspita; Zavřel, Vojtěch; Torrens-Galdiz, J. Ignacio; Hensen, J. L.M.; Tecnalia Research & InnovationThe increasing digitalisation of data is resulting in the need for ever greater computational capacity, which in turn leads to the increasing energy consumption in data centres. A large percentage of this energy use arises from the need to mechanically remove an enormous amount of heat from the data centre environment. In fact, in current practice, the mechanical infrastructure (especially cooling systems) of the data centre accounts for up to half of the overall energy consumption. To reduce the energy consumption of the mechanical infrastructure, several economisation methods are commonly implemented in cooling systems, one of which is the application of a direct air-side economiser addressed in the current research. The use of an air-side economiser has been shown to lead to major savings of the cooling electricity demand, and, as such, it has been widely used as a necessary addition to conventional cooling systems. This study analyses the energy breakdown of data centre cooling systems that include an air-side economiser in order to determine which components within the system are responsible for the major energy consumption. This study investigates, via a computational simulation, the impact of the use of a conventional cooling system and a system with an air-side economiser on total energy demand in three locations representing different climate regions in Europe. The study is especially focused on the energy demand related to the humidity treatment in the data rooms, since the effect is rarely considered in the overall DC energy balance. The results demonstrate, as expected, that the air-side economiser can yield major savings of around 62.5% to 78.7%, depending on the given climate regions. However, the key result of this study is that the humidity treatment necessary for the direct air-side economiser system may consume up to 34.8% of the total energy demand of the cooling system with the air-side economiser. © 2018, Society of Environmental Engineering.