Control solar en envolvente vidriada tropical para mejorar el desempeño energético-ambiental por climatización

Con el objetivo de fundamentar la estrategia de control solar como propuesta efectiva en la rehabilitación energética de un edificio de oficinas de los años 50´s, se realiza un diagnóstico del comportamiento de la demanda energética por climatización debido a su fenestración translúcida. Para el estudio se modelan los tipos de espacios más comunes (con una, dos o tres fachadas de vidrio) los cuales son objeto de simulaciones horarias que permiten pronosticar la demanda de energía anual para enfriamiento. Además, se determina el impacto ambiental que provoca este tipo de carpintería en las condiciones tropicales, de alta incidencia solar y de producción de energía de Cuba. Se utiliza Energy Plus, el motor más reconocido y avanzado de Simulación Energética de Edificios, desarrollado por el Departamento de Energía de los EEUU. Fundamentadas en los resultados se realizan y evalúan dos propuestas de diseño de control solar en las fachadas sureste y suroeste, las cuales demuestran su efectividad a partir del ahorro pronóstico anual de energía eléctrica por climatización consecuencia del recurso de sombreado. También se demuestra la influencia de la orientación en el diseño de los elementos componentes de la envolvente vertical para favorecer, con su especificidad local, la eficiencia energética, la identidad; así como la cultura energética convocada por la dirección de la nación. In order to justify the strategy of solar control like effective proposal in the energetic rehabilitation of an office building of the years 50 ´s. This paper present a diagnosis of the behavior of the cooling energetic demand due to its glazed windows. For the study are modeled the types of spaces more common of the building (with one, two or three glass facades) which are simulated each one hour to predict the annual energy demand for cooling. In addition, the environmental impact is determined that causes this window type in the tropical conditions, of high solar incidence and dependence of fuels imported for the energy generation in Cuba. It is used Energy Plus the most advanced motor in Energy Simulation of Buildings, developed by U.S. Department of Energy Building Technologies Office. Based in the results are carried out and evaluate three designs of solar control in the facades southeast and southwest, which demonstrate their effectiveness in the saving annual of electric power for cooling. The results demonstrate the influence of the orientation in the design of the vertical envelope component elements to favor, with their local specificity, the energy efficiency and the identity, as well as the energetic culture convoked by the government of the nation.

Comparison between Energy Simulation and Monitoring Data in an Office Building

One 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).

Thermal modelling and simulation of a laboratory building for cooling energy consumption

The main objective of this study is to identify and calculate the necessary variables for a building that can be used as input data in energy simulation tools and to determine the cooling energy consumption buildings and to examine the influence of applying energy rationalization measures. Based on that, we developed, applied, and validated a Simulink-based energy demand model of a governmental building to quantify the amount of cooling energy consumption in a case study environment. The model includes an air conditioner (plant model), controlled by a thermostat (controller model), to cool the laboratory building (environment model) to the desired temperature. The processes used here to construct the model layout and algorithm design can be extended to accommodate other multipart models or different construction sectors.