Statement of Peer Review

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Indoor monitoring of Scrovegni Chapel Crypt

The indoor microclimate of the Scrovegni Chapel in Padova (Italy) was analysed first in the ‘80s. The early study operates in the best way for what concerns the choice of measurement devices and their positioning. Starting from 1995 a Scientific-technical Board coordinates the various initiatives commissioned for the surveys of a conservation of the Scrovegni building structures and for the preservation of frescos. However only during the last ten years, the activities of the Board have been addressed also on the study of the hypogeal environments under the Chapel and in the external environment around it in order to prevent possible damage due to the presence of water which frequently submerges the floor and part of the vertical structures of the crypt (perimeter walls and brick partitions). The investigations have been therefore extended to the crypt. The present work reports the preliminary results of the cyclical survey campaign launched last year and still ongoing: passive thermographic techniques (non-invasive and non-destructive) have been used for the identification and the investigation of the relationship between the boundary seasonal thermohygrometric conditions and the rainfall variations and other exogenous phenomena related to the complex water system of the area on which the Scrovegni Chapel stands

Monitoring Moisture Diffusion after Contact Sponge Application

The contact sponge method is applied on a piece of clay brick. According to the standard, the sponge is moistened with water, applied on the surface of the material by means of a cup, and weighted before and after the application. It allows us to determine the amount of water absorbed by the porous material by unit area and unit time. After the application, the moistened area begins to evaporate and cool down. The IR camera is used to monitor the temperature variation of the imprint of the sponge. Meanwhile, moisture diffuses on the material as well. The IR camera is used to monitor the in-plane diffusion of moisture by following the imprint of the sponge that enlarges with time. A suitable model is used to evaluate the shape of the imprint that varies with time

Numerical Model and Experimental Analysis of the Thermal Behavior of Electric Radiant Heating Panels

Electric radiant heating panels are frequently selected during the design phase of residential and industrial heating systems, especially for retrofit of existing buildings, as an alternative to other common heating systems, such as radiators or air conditioners. The possibility of saving living and working space and the ease of installation are the main advantages of electric radiant solutions. This paper investigates the thermal performance of a typical electric radiant panel. A climatic room was equipped with temperature sensors and heat flow meters to perform a steady state experimental analysis. For the dynamic behavior, a mathematical model was created and compared to a thermographic measurement procedure. The results showed for the steady state an efficiency of energy transformation close to one, while in a transient thermal regime the time constant to reach the steady state condition was slightly faster than the typical ones of hydronic systems

16th International Workshop on Advanced Infrared Technology and Applications (AITA 2021)

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INNOVATIVE SOLUTIONS FOR METAL GROUND HEAT EXCHANGERS

Gli edifici sono responsabili del 40% del consumo energetico globale e di circa il 30% delle emissioni di gas serra. Per questo motivo, garantire che gli edifici nuovi ed esistenti siano sostenibili ed efficienti dal punto di vista energetico è l'obiettivo principale degli sforzi della Commissione europea per contrastare il cambiamento climatico . L'energia geotermica a bassa entalpia è una fonte di energia costante, affidabile e rinnovabile disponibile quasi ovunque. I sistemi geotermici a pompa di calore si sono dimostrati efficaci nel limitare il consumo di energia per le esigenze di riscaldamento e raffrescamento degli edifici. Tuttavia, è necessario continuare la ricerca in questo campo, perché esistono barriere tecniche che limitano la diffusione di questi sistemi, che vanno pertanto ulteriormente sviluppati e resi più efficienti, più economici e più sicuri. Questa tesi descrive la ricerca e le innovazioni ottenute nell'ambito del progetto Horizon 2020 GEO4CIVHIC incentrate sul miglioramento di uno dei componenti cruciali dei sistemi geotermici superficiali: lo scambiatore di calore a terreno, nello specifico quelli in metallo. Gli scambiatori di calore a terreno (GHE) sono tubi inseriti nel terreno all'interno dei quali scorre un fluido che consente il trasferimento di calore con il terreno stesso. La loro efficacia dipende principalmente dal contesto geologico locale, che implica stratigrafia e condizioni idrologiche, nonché dai materiali e dalla tecnologia utilizzati per costruire i GHE. Questa tesi, dopo una parte introduttiva, descrive metodi e procedure tradizionali e innovativi volti a determinare le proprietà termofisiche di diversi tipi di GHE metallici. I metodi proposti vengono poi applicati per studiare l'interazione tra il GHE e l’ambiente circostante, ovvero il sottosuolo, che comprende anche il suo contenuto idrico dovuto alle falde acquifere e le sue stesse proprietà chimico-fisiche. Lo studio si è concentrato sugli effetti di queste interazioni sulle prestazioni di trasferimento del calore e, a lungo termine, sulla corrosione e sulla durata dei tubi. Soluzioni e misure preventive praticabili per rendere gli scambiatori di calore metallici efficienti, convenienti e più sicuri sono state identificate e applicate su un caso studio reale. Queste includono lo sviluppo e l'implementazione di un modello sperimentale di GHE e la proposta di metodi di ispezione non distruttivi basati sulla termografia a infrarossi.Buildings are responsible for 40% of global energy consumption and about 30% of greenhouse gas emissions. In fact, ensuring that new and existing buildings are sustainable and energy efficient is the main goal of European Commission efforts to challenge climate change . Shallow geothermal energy is a constant, reliable and renewable energy source available almost everywhere, and geothermal heat pump systems have proven to be effective in limiting energy consumption for the heating and cooling needs of buildings. However, the need for research and improvement is mandatory because there are technical barriers that limit the spread of these systems, which need further development to be made more efficient, cheaper and safer. This thesis describes the research and innovations obtained in the frame of Horizon 2020 GEO4CIVHIC project focused on improving one of the crucial components of shallow geothermal systems: the ground heat exchanger, focusing on the metal ones. Ground heat exchangers (GHE) are tubes inserted into the ground inside which a fluid flows that allows heat to be transferred to the ground. Their effectiveness depends mainly on the local geological context such as stratigraphy and hydrological conditions and on the materials and technology used to build the GHEs. This thesis, after an introductory part, describes traditional and innovative methods and procedures aimed at determining the thermophysical properties of different types of metallic GHEs. The proposed methods are then applied to study the interaction between GHEs and the environment, that is the underground which also includes its water content due to groundwater and its characterizing chemophysical properties. The study focuses on the effects of these interactions on heat transfer performance and, in the long term, on corrosion and pipe life. Workable solutions and measures to make metal ground heat exchangers more efficient, cost effective and safer have been identified and applied on a real case study. These include the development and implementation of an experimental type of GHE and the proposal of non-destructive inspection methods based on infrared thermography

Multiple Shots Averaging in Laser Flash Measurement

The laser flash method is a well-known procedure to determine the thermal diffusivity of a wide range of materials. However, in some cases there is the need of limiting the input power, measuring materials with high thermal capacity, or investigating thick samples. These conditions lead to a reduction of the signal-to-noise ratio. Therefore, we propose a new laser flash control and data acquisition system, that is able to repeat multiple times the emission of the laser impulse and the measurement of the thermal response of the specimen. With the average of several measurements, it is possible to obtain a decrease of the noise when working with low power inputs. (C) 2020 Optical Society of Americ

Multiple shots averaging in laser flash measurement

The laser flash method is a well-known procedure to determine the thermal diffusivity of a wide range of materials. However, in some cases there is the need of limiting the input power, measuring materials with high thermal capacity, or investigating thick samples. These conditions lead to a reduction of the signal-to-noise ratio. Therefore, we propose a new laser flash control and data acquisition system, that is able to repeat multiple times the emission of the laser impulse and the measurement of the thermal response of the specimen. With the average of several measurements, it is possible to obtain a decrease of the noise when working with low power inputs. (C) 2020 Optical Society of Americ