Juan J. Sendra

Acoustic evaluation of the cathedral of Seville as a concert hall and proposals for improving the acoustic quality perceived by listeners

The acoustic evaluation of the cathedral of Seville as a concert hall is carried out through the simulation of acoustic models derived from the modification of the model of the current state and calibrated using the results of in situ measurement. These models reproduce the configurations adopted for major music concerts held there regularly. The results obtained led to the proposal of a new layout plan for an audience of 1500 people and other corrective measures in keeping with the history of the cathedral and compatible with its heritage value, improving subjectively perceived sound. This is assessed in terms of subjective reverberation, evaluated through early decay time, the perceived sound level and the uniformity of the sound field (measured with sound strength parameter), perceived clarity (assessed through clarity and central time parameters), and the spatial sensation (assessed through early lateral energy fraction).

Towards finding the optimal location of a ventilation inlet in a roof monitor skylight, using visual and thermal performance criteria, for dwellings in a Mediterranean climate

The main aim of this work is to study the influence of a roof monitor skylight on comfort criteria. The roof monitor skylight simultaneously provides lighting and outdoor ventilation air for a living room or a master bedroom in a house with an underfloor heating/cooling system. The air is introduced into the room through an air inlet in the carpentry of the opening in the roof monitor skylight and located – for the purposes of this study – in different positions in the carpentry. To evaluate the comfort variations caused by this change of position, a series of lighting and thermal numerical indicators are applied to a set of simulation models, generating a complete analysis to determine optimal positions for the air inlet. These models are designed for the context of a Mediterranean climate, with extreme calculation conditions (overcast sky in winter and clear sky in summer). The simulation tools Daylight Visualizer 2.5 and Design Builder 2.42 have been selected to generate the models. This work concludes that the optimal position for the air inlet is in the side of the carpentry of the roof monitor skylight opening, ensuring the maximization of both lighting and thermal comfort conditions.

Simulated acoustic field in mudejar‐gothic churches

The most significant acoustic parameters in a set of mudejar‐gothic churches were measured (all the churches were located in the city of Seville). From the analysis of these data important conclusions were otained about the behavior of the reverberant field versus source–receiver distance [J. Sendra et al., Computational Acoustics and its Environmental Applications—II (Computation on Mechanics Publications, Southampton, 1997), pp. 139–148] from Barron‘s revised theory [Barron et al., J. Acoust. Soc. Am. 84, 618–628 (1988)] and the relations between several acoustics quality descriptors: C80, D50, and RASTI [Zamarreno et al., Proceedings Acustica‐98, Lisbon (1998)]. The three most representative churches were chosen to carry out a computer simulation with the raynoise software. Absorption coefficient values used in the model have been adjusted using measured reverberation time data, and thus the results were obtained for the other acoustic parameters in the different octave bands. It was proven that, in ge...

Implementation Of Urban Building Energy Modeling In Historic Districts. Seville As Case- Study

Buildings represent 40% of the European Union’s final energy consumption and are largely of residential use. From 2006 to 2016, existing European housing stocks have been analysed at national level to make the energy refurbishment processes transparent and effective. However, at the metascale of regions, cities or neighbourhoods, case-by-case analysis using Building Energy Models (BEM) becomes an unfeasible decision-support tool. To try to overcome this limitation, the nascent field of Urban Building Energy Modelling (UBEM) is making substantial progress in the assessment of building energy performance at urban scale. Still, most of the UBEM projects rely upon archetypes – i.e. virtual or sample buildings illustrative of the most frequent characteristics of a particular category, and the definition and description of such archetypes may compromise their reliability. This paper presents an alternative UBEM approach, especially designed for the homogeneous historic districts of cities where a significant proportion of the buildings are under preservation rules. These rules can restrict the scope of the measures to improve their energy efficiency or limit the possibility of implementing renewable energy systems. We introduce a new parameter (HAD) to classify blocks according to their heritage asset density. HAD is then mapped onto the study-area and the sample block is selected as representative of the most frequent HAD category. Using the historic ensemble of Seville as case-study, this paper shows results in energy consumption on a district scale and proposes a set of solutions to improve the energy efficiency of the buildings while respecting the heritage preservation rules. To support consistent policy decisions, validation of these results has been carried out, by in-situ monitoring of a representative number of dwellings.

Validation of a Dynamic Simulation of a Classroom HVAC System by Comparison with a Real Model

Schools require thermal comfort in their classrooms , but some uncertainty arises as how their HVAC systems will actually provide it, especially given their high internal loads and mechanical ventilation diffusion. Thus, it is necessary to resort to computational fluid dynamics (CFD) for developing predictive models; nevertheless, the reliability of the simulation tool has to be verified, so the main objective of this work is to define and perform the validation process of a thermal dynamic simulation tool by comparison with a real room. A validation protocol has been detailed for dynamic simulation tools, in medium-sized spaces with high internal loads, by comparing with the measured air temperature values of an existing standard classroom, according to ISO 7726:2002. The chosen standard classroom for this comparison belongs to “Eca de Queiros” secondary school of Lisbon (Portugal). To that effect, 80 thermocouple sensors were used for the characterization of its indoor thermal behaviour. A mean bias error (MBE) of 0.21 °C was obtained, with a maximum standard deviation of 0.47 °C, which is under the maximum limit of ±0.5 °C established by this standard. The application of this methodology for validating the Design Builder software proves the reliability of this tool in such type of venues.

The mur neutralisant as an active thermal system: Saint Gobain tests (1931) versus CFD simulation (2015)

Abstract: At the same time as the initial development of air conditioning systems for indoor climate control in buildings were occurring in USA, Le Corbusier and Lyon made truly innovative proposals for different projects he was working on in Europe. These served to generate homogenous thermal environments and focused on the combined effect of his mur neutralisant and respiration exacte. The clearest example of their shortcomings is the City of Refuge in Paris (1930-33). Given the technological and economic mistrust towards these proposals, as it was impossible to execute these according to the original plan these were not pursued. CFD simulations carried out by our research team confirm that the mur neutralisant and respiration exacte for the City of Refuge in Paris would have functioned together if they had been executed following the original plans. The main aim of this paper is to confirm the validity of the mur neutralisant as an active thermal system for buildings. Firstly, the results of the tests carried out by the engineers of Saint Gobain are compared to the results of the CFD simulations. Based on the comparison of the results from the physical models tested in Saint Gobain laboratories and CFD energy model simulations, a possible calibration is proposed for CFD which might prompt the establishment of other operation hypotheses. Keywords: Le Corbusier; mur neutralisant; The City of Refuge; Active Facade System; Computational Fluid Dynamics (CFD); Numerical Simulation. DOI: http://dx.doi.org/10.4995/LC2015.2015.899

La investigación arquitectónica, el proyecto de arquitectura y el acondicionamiento ambiental en el proyecto de adecuación de la planta principal del Palacio de Carlos V de Granada

The Charles V Palace is located in the Complex of Monuments of the Alhambra in Granada; despite the fact that it appears to be a fi nished building according to the design by Pedro Machuca, actually it was never completed. It is a clear example of what modern history writers would term a “longduration” building. Its main fl oor currently houses the Fine Arts Museum of Granada. The proposal to install this museum here was put forward in the 1940s, after the palace was completed in 1928 by Torres Balbas. The project was implemented by F. Prieto Moreno and the museum was opened in 1958. In 2000, the project to adapt the main fl oor of the Charles V Palace was drawn up. This project has already been implemented, although the museum project is expected to be completed in 2007. Based on architectural research, the abovementioned project includes environmental conditioning of the palace rooms, especially light, hygrothermal and air quality conditioning, as well as the installations required for exposition purposes, which mainly guarantee the visual observation of the works of art on display, conservation conditions of these works, visitors’ comfort and energy effi ciency. This article details the respectful way in which this adaptation project is meeting those objectives.

Sound Field In Several Theatres Of Cadiz, Before And After Its Restoration

In order to recover the historical and architectural heritage in our region, the Andalusian Goverment is carrying out since recent times a quite interesting an important project called Rehabilitation Plan of Theaters in Andalusia. This ambitious project, still running, includes the rehabilitation of more than thirty andalusian theaters, and inside it we are playing the role of acoustic consultors at the request of the region administration. Five of these theaters belonging to the the Cadizs province has been already rehabilitated and reopened for different uses. They are: Manuel de Falla Theater, in Cadiz, Villamarta Theater in Jerez de la Frontera, Principal Theater in Puerto Real, Olivares-Veas Theater in Arcos de la Frontera, de las Cortes Theater, in San Fernando. They are characterised because they cover a quite wide range of volumes (scene excluded), oscillating between 790 m 3 , in Olivares-Veas Theater, and 8114 m 3 , in Manuel de Falla Theater, and seats that oscillate between 221, in Olivares-Veas Theater, and 1221, in Villamarta Theater. This paper will be devoted to show the results, experimental and modelled, obtained for severals room acoustic parameters, before and after the perfomed restoration in the five theaters previously mentioned. These results will be discussed according to the diferent uses foreseen for these theaters and consequently the success of the restoration perfomed in them will be evaluated from the acoustical point of view.

A Proposal To Improve The Acoustics In Fernandina Churches. The Example OfMagdalena Church In Cordoba (Spain)

After the Christian conquest of Cordoba by Fernando I11 in 1236, small churches were erected in substitution of Muslim mosques. Thus arises the Fernandina church model which will become a church archetype after the Reconquest. They are simple churches, with three naves covered with wooden roof structures and domed apses that satisfied the needs of liturgy and preach at that time, in which music was enphasized over speech. Nowadays many of those churches combine their liturgical activities with cultural uses. In this work the acoustic conditions of this church model are studied. An acoustic analysis on one of these type of churches will be applied: Magdalena church, which has been recently restored for cultural uses. From measuring taken in situ together with computer simulation, architectural solutions are proposed to adapt the acoustics of the space to both speech and music use.

Acoustical behavior of churches: Gothic‐Mudejar churches

Traditionally, a particularly good acoustic behavior has been assigned to Christian churches. But this statement, which is not true at all, has led to important errors in church rehabilitation works, more so in those that implicate changes of use, such as auditoriums or theatrical halls, which is the case of many churches in Spain. This research group has worked in acoustical analysis for more than ten years, and has participated in many cases of church rehabilitation, among which is acoustical behavior. We are talking about a type of church very common in the south of Spain, Gothic‐Mudejar churches. They are churches with these common characteristics: relatively little volume, plants with three naves, and wooden ceilings. With this work, significant conclusions drawn from the acoustical analysis of ten churches of Seville that respond to this type are presented. Their characteristics are quite homogeneous, so it is possible to get conclusions about the acoustical conditions of this ecclesiastical type.