1,721,003 research outputs found
Sensitivity to the Reference Buildings Choice of the New Energy Requirements: an Application of the Regulation EU 244/2012
No full textENERGY PERFORMANCE OF DIFFERENT GLAZING TYPES IN AN OPEN-SPACE OFFICE WITH CONTROLLED INDOOR THERMAL COMFORT
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Extensive Utilization Of Dynamic Simulation For Sensitivity Analysis And Optimization Design Of Refurbishment Measures
Get PDFStatistics and, in particular, sensitivity analysis represent an important tool for the building designer to find information about which parameters have the largest potential in reducing the energy consumption or which are the most crucial to focus on in the different phases of the project process. The application of dynamic simulation to a large number of configurations (i.e. the extensive simulation) to find the optimal solution either considering only the energy aspects or also the economic impacts and not only to evaluate a small set of possible alternatives, represents in that perspective a new approach to the building design, in particular for refurbishment considerations. This work aims to evaluate and generalize this kind of approach with its application to the refurbishment of residential buildings. The considered design solutions represent the most common measures of improvement of the performance of opaque and transparent envelope, such as the insulation level of walls and windows and the solar properties of the glazings. Different starting cases characterized by different envelope thermal inertia, corresponding to three massive materials (timber, clay and concrete), and different geometrical features were studied. A large number of environmental conditions, envelope characteristics and refurbishment interventions have been analyzed within a factorial simulation plan. Among those parameters, the ratios between the dispersing envelope and the volume conditioned (considering 3 different floors of a building – the top, the intermediate and the ground floor), the windows size (small or large size) and their distribution (South, East or West oriented), the level of insulation of the opaque envelope (starting cases without insulation, poor insulated and high insulated cases) and the kind of glazings (starting cases with single glasses and improved cases with double or triple glasses with high or low Solar Heat Gain Coefficient, SHGC) have been examined. Three Italian climates (Milan in the North, Rome in the center region and Messina in the South) were considered as representative of the Southern Europe. The inferential statistical analysis has been used to identify the predominant factors in each refurbishment solution and the economical savings both in heating and in cooling
Energy Performance And Long-Term Evaluation Of Internal Thermal Comfort Of An Office Building With Different Kinds Of Glazing Systems And Window Sizes
Get PDFAlthough the presence of large window surfaces could be preferable during the heating season when solar gains through the glazed components can overcome heating losses from the same surfaces, during the cooling season more attention has to be paid in order to limit the inlet of solar radiation which causes the increment of cooling load. Generally the optimal tradeoff for energy optimization, as already underlined in a previous paper by the authors, is using low thermal transmittance and high solar factor glazing, even if higher solar transmittance considerably worsens the cooling performance. However, the choice of glazing type and the design of windows on a façade may depend on comfort consideration besides energetic evaluations. Thermal sensation of an individual is mainly related to the whole thermal balance of the human body. Comfort limits can in this case be expressed by two indexes proposed by Fanger in 1970: the Predicted Mean Vote, PMV, and the correlated Predicted Percentage of Dissatisfied, PPD. The PMV depends on four environmental parameters (air temperature, air humidity, air velocity and mean radiant temperature) and two variables connected with human being (physical activity and clothing). The air temperature, the air humidity and the air velocity inside a building are directly under the system control. In contrast, the mean radiant temperature is strongly conditioned by the envelope surface temperature, and in particular, by the presence of glazed surfaces whose insulating performance is lower than the opaque components one. In this paper the study of heating and cooling energy needs of an open-space office with different windows’ characteristics has been carried out controlling the internal comfort conditions with appropriate setpoint of the system. An office module with windows on a single façade, or on opposite façades, oriented towards 3 different orientations has been simulated, varying the glazed area (2 sizes), the glazing systems (4 types) and considering three localities of central and southern Europe. The PMV have been calculated for each hour of occupation of the whole year assuming two season as regards the setpoint conditions and clothing level. Calculations have then been repeated considering also the effect of the diffuse and beam solar radiation through the windows directly reaching the occupants. The evaluation of the long-term comfort conditions (on seasonal basis) has been conducted considering some statistical indicators of distribution (the median, minimum, maximum and the interquartile range) and the energy performance of the different glazing solution have been compared accounting for the comfort one
Analysis and modelling of window and glazing systems energy performance for a well insulated residential building
No full textThe energy performance of a window depends on its thermal transmittance, the glazing solar transmittance, and the air leakage due to the frame and installation airtightness. In new installations air leakage represents a quite small term which is almost independent from the window and in particular from the glazing system selection. The contributions of the two other terms to the building thermal balance are not independent to each other: the most effective thermal insulating glazing, as triple glazings, are generally characterized by low solar transmittance reducing solar gains. The thermal energy balance of the building is then affected not only in summer but also in winter, potentially increasing heating energy need. This work evaluates the impact of different kinds of glazing systems (two double and two triple glazings), window size (from 16% to 41% of window to floor area ratio), orientation of the main windowed façade and internal gains on winter and summer energy need and peak loads of a well insulated residential building. The climatic data of four localities of central and southern Europe have been considered: Paris, Milan, Nice and Rome. A statistical analysis has been performed on the results in order to identify the most influencing parameters
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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