Monitoring Heritage Buildings with Open Source Hardware Sensors: A Case Study of the Mosque-Cathedral of Córdoba

IoT-Based Microclimate and Vibration Monitoring of a Painted Canvas on a Wooden Support in the Monastero of Santa Caterina (Palermo, Italy)

The main objective of this work is the characterization and observation of the performance of an IoT measurement and monitoring system in the field of cultural heritage conservation for assessing the health condition of artworks. This article also describes the application of this system to the monitoring of a canvas painting applied on a wooden support, an artwork from the 19th century by the painter Giuseppe Patricolo depicting The Deposition, placed inside a niche in the Santa Caterina Monastery in Palermo (Italy). Considering the presence of the wooden structure, it is useful to measure not only microclimatic parameters such as temperature and humidity, but also vibrations that can in fact cause degradation phenomena in these artworks. This is a first step towards the development of mimetic systems integrated in the work of art without causing physical, mechanical or chemical alterations and ensuring that the level of microclimatic parameters is below the threshold values whose exceeding could compromise the entire artefact.

Graphic Engineering in the Sustainable Preservation of the Municipal Heritage of Montilla (Cordoba, Spain) from the 18th Century: Master Builder Vicente López Cardera in Montilla

The change of territorial organisation in the 18th century in Spain was strongly related to the preservation of the local heritage. Academic architects, military engineers, and master builders coexisted to carry out the design and management of municipal construction works. The evolution of the figure of the master builder and the confrontation with architects and the guilds since the creation of the Royal Academy of Fine Arts of San Fernando posed an inflection point in this aspect. The first aim of the present study was to highlight the figure of Vicente López Cardera, master builder in the Council and Diocese of Córdoba between the late 18th century and the early 19th century, through his work on the municipal interventions in the maintenance of the construction works and infrastructures in Montilla (Córdoba, Spain) around the year 1794. The second aim of the study was to emphasise the role of graphic engineering in the conservation of municipal heritage in the Modern Age through the study of drawings and plans provided by him in the analysed documentation. His thinking in the approach to these works fits with the ideas of social hygienic improvements that began with the Enlightenment as well as with the concept of sustainable development in culture; hence, his work is relevant in the sustainable development planning of cities in the present. With this study, missing heritage elements are also revealed, opening future lines of research that lead to their virtual reconstruction and the promotion of tourism in rural areas.

A Novel Data Acquisition System for Obtaining Thermal Parameters of Building Envelopes

Owing to the high energy consumption in the building sector, appraising the thermal performance of building envelopes is an increasing concern. Recently, a few in situ methodologies to diagnose the thermal parameters of buildings have been considered. However, because of their limitations such as low accuracy, limited number of measurements, and the high cost of monitoring devices, researchers are seeking a new alternative. In this study, a novel hyper-efficient Arduino transmittance-meter was introduced to overcome these limitations and determine the thermal parameters of building envelopes. Unlike conventional methodologies, the proposed transmittance-meter is based on synchronized measurements of different parameters necessary to estimate the transmittance parameter. To verify the applicability of the transmittance-meter, an experimental study was conducted wherein a temperature-controlled box model was thermally monitored, and the outputs of the transmittance-meter employed were compared with those captured by a commercial device. The results revealed a high level of reduction in cost and a low range of difference compared with the latter, thereby validating the applicability of the proposed thermal monitoring system.

Historic Climate in Heritage Building and Standard 15757: Proposal for a Common Nomenclature

Research on the relationship between microclimate and heritage buildings or historic buildings has increased dramatically in the last few decades. Research has focused on indoor climate or indoor microclimate or the environment or micro-environment, and the field of these studies regards several variables, physical—air temperature, air speed, relative humidity—or chemical, dust, CO2, pollution, etc., all of which can have an effect or damage buildings or artifacts inside buildings. Moreover, all these variables should be monitored in a monitoring campaign following the standard EN 15757; in spite of this, scientific literature contains mistakes with regard to the words and objects of study. In this short contribution, the author proposes a common nomenclature in the research field of climate and microclimate in heritage buildings and heritage artifacts. A new nomenclature should be useful for the community of heritage scientists working on preventive measures to distinguish between climate and environment, or the object of study, e.g., the room (wall, wood structure, fresco, etc.) where the artifacts are or the air around them (painting, canvas, statue, piece of furniture, documents, books, etc.).

Multivariate Characterization of Temperature Fluctuations in a Historical Building Using Energy-Efficient IoT Wireless Sensors

Adequate thermic conditions are required for the preventive conservation of artworks, but such optimum conditions cannot always be achieved in historical buildings such as ancient churches. In those cases, it is of interest to assess the potential risk of punctual changes in indoor environments that can be harmful to artworks. These conditions can be assessed by means of a microclimate monitoring system comprised of a set of energy-efficient wireless sensors connected to the cloud using IoT techniques. This approach was followed at the baroque church of Saint Thomas and Saint Philip Neri in Valencia (Spain). A set of 26 wireless nodes was installed, which recorded values of temperature and relative humidity every hour for a period of 7 months. Small differences of temperature were obtained among sensors, so that an efficient methodology based on principal component analysis (PCA) was applied for the characterization of similarities and dissimilarities between sensors. Daily ranges of temperatures were studied as well as mean trajectories, differences between days of the week, and changes in the correlation structure of daily median values over time. Results provide a framework for an efficient characterization of temperatures in heritage buildings based on a network of wireless sensors. Such a framework is useful to assess the potential risk of temperature fluctuations on the preventive conservation of historical buildings and artworks.

Improving Energy Performance of Historic Buildings through Hygrothermal Assessment of the Envelope

The intervention on historic buildings through building energy retrofitting has become one of the current challenges of improving energy efficiency. Nonetheless, this building typology presents certain complexities. Among them, one of the most relevant is the protection on their façades due to the historical and/or artistic values of a given façade and, therefore, the addition of external thermal insulation is restricted. However, at the same time, in several of those buildings indoor surfaces do not present that architectural value, and then internal thermal insulation becomes a promising strategy for improving their thermal performance. Nevertheless, its application must be carefully evaluated to avoid possible pathologies caused by moisture problems. This paper aims to identify constructive solutions for interior insulation of walls free from moisture problems. For this purpose, a comprehensive analysis of a series of constructive solutions based on internal insulation has been carried out through hygrothermal simulations. The results show how the application of water-repellent impregnation becomes essential to guaranteeing the integrity of the envelope. In addition, the combination of insulations with or without inner membranes, such as smart vapor retarders or vapor diffusion barriers, has been evaluated detecting the solutions that best fit the objective. Finally, taking advantage of the great potential of 2D simulation tools, the post-processing of the data has been performed to apply the wood decay model, and thus assess the behavior of a very conflictive point in this type of intervention, i.e., the wooden beam-ends. The results in this critical point have shown how the application of the proposed constructive solutions becomes essential to guarantee the integrity of the element and how the application of traditional solutions could lead to a hazard that must be avoided.

Proposing 3D Thermal Technology for Heritage Building Energy Monitoring

The energy monitoring of heritage buildings has, to date, been governed by methodologies and standards that have been defined in terms of sensors that record scalar magnitudes and that are placed in specific positions in the scene, thus recording only some of the values sampled in that space. In this paper, however, we present an alternative to the aforementioned technologies in the form of new sensors based on 3D computer vision that are able to record dense thermal information in a three-dimensional space. These thermal computer vision-based technologies (3D-TCV) entail a revision and updating of the current building energy monitoring methodologies. This paper provides a detailed definition of the most significant aspects of this new extended methodology and presents a case study showing the potential of 3D-TCV techniques and how they may complement current techniques. The results obtained lead us to believe that 3D computer vision can provide the field of building monitoring with a decisive boost, particularly in the case of heritage buildings.

Digital Twin: Research Framework to Support Preventive Conservation Policies

Preventive strategies for the conservation of heritage sites have gradually been preferred to curative approaches because of their ability to maintain their significance. Furthermore, most experts now agree that conservation management of heritage places based on a common understanding of their cultural values is essential to address all the particularities of their contexts. Recently, significant research has demonstrated the potential of Heritage Building Information Modelling (HBIM) for the collaborative data management in conjunction with conservation projects. The recent development of HBIM web platforms illustrates the value of strengthening the link between the digital model and the physical realm of heritage assets. This paper advocates the application of Digital Twin’s (DT) principles, using HBIM models as a digital replica, to support the preventive conservation of heritage places. Based on an extensive literature review, a comprehensive framework that integrates the DT into the management plan process for the preventive conservation of built heritage is proposed. Several recommendations for its implementation are finally discussed, such as the identification of tangible features of significance, the threats associated with their integrity and the corresponding mitigation strategies, with particular emphasis on the value assessment process. The result is a data model for structuring information on preventive conservation strategies. This framework provides the basis for future implementation and demonstrates the need for a DT approach in this context.

Internet of things in the archives: novel tools for environmental monitoring of archival collections

Purpose

Cultural heritage archives rely on environmental monitoring devices, such as dataloggers or more complex networked systems, to ensure collection preservation through collecting temperature, humidity, light and/or air quality measures. Existing systems are often costly, inflexible and do not use a modern, internet of things (IoT) approach. This paper aims to determine the suitability of currently popular general-purpose IoT devices, standards and technologies to the environmental monitoring needs of archivists, as well as identify any challenges.

Design/methodology/approach

This paper describes an exploratory study detailing the design, construction and usability testing of a do-it-yourself datalogger and data dashboard system, which seeks to manage previously identified trade-offs in cost, required technical skill and maintainability.

Findings

The environmental monitoring system presented met archivists’ needs well and was generally noted to be easy-to-use, efficient and an improvement on existing systems. This suggests that an IoT approach can support archivists’ needs in this area.

Research limitations/implications

Potential limitations of this study include lack of archival staff with sufficient technical training to maintain such a system and the rapid pace of IoT evolution yielding unstable and constantly changing technologies.

Practical implications

The system design presented in this work provides a blueprint for cultural heritage organizations desiring a fuller-featured, lower cost environmental monitoring system for archival collections.

Originality/value

This research takes a novel user-centered, open-source, IoT approach to construct an environmental monitoring system that is designed directly from archivists’ requirements and is extensible for future needs.

Environmental Monitoring of Ancient Buildings Based on a Wireless Sensor Network

Environmental monitoring plays an important role in the preventive protection of ancient buildings, although it is still in the prototype stage. In order to provide data support for the protection of ancient buildings, an environmental monitoring system with multi-sensor and multi-node for the interior and exterior of ancient buildings is designed and realized, based on ZigBee, TCP/IP, and intranet penetration technology. The new type of indoor node package box and outdoor package device are designed to meet the needs of different types of sensors. The monitoring platform is developed on the strength of the LabView so as to obtain real-time display, storage, and over-limit warning functions for local and remote monitoring data. It also proves that the monitoring system is stable and reliable by monitoring the actual ancient building with a brick (stone) structure.

The Development of an Open Hardware and Software System Onboard Unmanned Aerial Vehicles to Monitor Concentrated Solar Power Plants

Concentrated solar power (CSP) plants are increasingly gaining interest as a source of renewable energy. These plants face several technical problems and the inspection of components such as absorber tubes in parabolic trough concentrators (PTC), which are widely deployed, is necessary to guarantee plant efficiency. This article presents a system for real-time industrial inspection of CSP plants using low-cost, open-source components in conjunction with a thermographic sensor and an unmanned aerial vehicle (UAV). The system, available in open-source hardware and software, is designed to be employed independently of the type of device used for inspection (laptop, smartphone, tablet or smartglasses) and its operating system. Several UAV flight missions were programmed as follows: flight altitudes at 20, 40, 60, 80, 100 and 120 m above ground level; and three cruising speeds: 5, 7 and 10 m/s. These settings were chosen and analyzed in order to optimize inspection time. The results indicate that it is possible to perform inspections by an UAV in real time at CSP plants as a means of detecting anomalous absorber tubes and improving the effectiveness of methodologies currently being utilized. Moreover, aside from thermographic sensors, this contribution can be applied to other sensors and can be used in a broad range of applications where real-time georeferenced data visualization is necessary.

Study on the Correlation between Humidity and Material Strains in Separable Micro Humidity Sensor Design

Incidents of injuries caused by tiles falling from building exterior walls are frequently reported in Taiwan. Humidity is an influential factor in tile deterioration but it is more difficult to measure the humidity inside a building structure than the humidity in an indoor environment. Therefore, a separable microsensor was developed in this study to measure the humidity of the cement mortar layer with a thickness of 1.5-2 cm inside the external wall of a building. 3D printing technology is used to produce an encapsulation box that can protect the sensor from damage caused by the concrete and cement mortar. The sensor is proven in this study to be capable of measuring temperature and humidity simultaneously and the measurement results are then used to analyze the influence of humidity on external wall tile deterioration.