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38 pages, 12996 KB  
Article
Street and Urban Muralism in Public Art: Conservation Between Evolution and Research in the Methods of the Istituto Centrale per Il Restauro
by Paola Mezzadri, Sara De Angelis, Rebecca Picca Orlandi, Michela Renna and Giancarlo Sidoti
Heritage 2025, 8(11), 483; https://doi.org/10.3390/heritage8110483 - 17 Nov 2025
Viewed by 295
Abstract
This paper presents an overview of a research line developed at the Istituto Centrale per il Restauro within the CHANGES (Cultural Heritage Active Innovation for Next-Gen Sustainable Society) project, funded under the Italian National Recovery and Resilience Plan. The research was developed in [...] Read more.
This paper presents an overview of a research line developed at the Istituto Centrale per il Restauro within the CHANGES (Cultural Heritage Active Innovation for Next-Gen Sustainable Society) project, funded under the Italian National Recovery and Resilience Plan. The research was developed in different phases: a first one dedicated to the study of the deep background and the state of the art in the ICR background: history, methodologies and research in the field; a second phase was dedicated to the selection of a specific urban art mural, as a key study with conservation problems connected to some of the principal preservation treatments related to the outdoor context; the mural was also identified as a beloved icon in the public space with a profound socio-cultural meaning for the community. Nido di Vespe, created in 2014 by the artist Lucamaleonte is part of a broader artistic project called M.U.Ro-Museum of Urban Art of Rome, an open-air public art museum located in the Quadraro district in Rome, designed by the artist Diavù. A third phase focused on the research in ICR laboratories, specifically addressing: cleaning, reintegration, and protection strategies adapted to dynamic outdoor environments. A multi-step cleaning system based on polyvinyl alcohol-borax semi-interpenetrated hydrogels loaded with nanostructured fluids was developed to selectively remove spray-paint vandalism while preserving the chemically similar original pictorial layers. The reintegration phase investigated acrylic and urea-aldehyde resins as binders to produce compatible, reversible, and UV-traceable retouching and infilling materials. For surface protection, multilayer coating systems incorporating nanoparticles with antimicrobial, photocatalytic, and UV-stabilizing properties were formulated to enhance durability and chromatic stability. Laboratory tests on mock-ups simulating typical street and urban art materials and morphologies showed satisfactory results, while diagnostic investigations on Nido di Vespe provided the reference data to calibrate the experiments with real mural conditions. Cleaning tests demonstrated promising removal efficiency, influenced by the chemical composition, thickness of the overpainted layers, and surface roughness. The reintegration system met the expected performance requirements, as the tested binders provided good results and allowed the development of compatible, reversible, and distinguishable solutions. Protective coatings showed good results in terms of chromatic stability and surface integrity; however, the long-term behavior of both reintegration, cleaning, and protection systems requires further evaluation. The results achieved so far support the development of sustainable and flexible conservation strategies for the conservation of contemporary street and urban murals and will guide the future application of the selected materials and methodologies in pilot conservation interventions on the mural chosen as a meaningful case study within the broader research. Full article
(This article belongs to the Special Issue History, Conservation and Restoration of Cultural Heritage)
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28 pages, 1796 KB  
Article
A BIM-Oriented Framework for Integrating IoT-Based Air Quality Monitoring Systems Using the AllBIMclass Classification
by Eduardo J. Renard-Julián, José M. Olmos and M. Socorro García-Cascales
Appl. Sci. 2025, 15(19), 10409; https://doi.org/10.3390/app151910409 - 25 Sep 2025
Viewed by 677
Abstract
This paper presents a BIM-oriented methodological framework for integrating air quality monitoring systems based on IoT sensors into building and infrastructure projects. A set of low-cost environmental sensors capable of measuring PM1, PM2.5, PM10, temperature, and humidity was deployed in a real residential [...] Read more.
This paper presents a BIM-oriented methodological framework for integrating air quality monitoring systems based on IoT sensors into building and infrastructure projects. A set of low-cost environmental sensors capable of measuring PM1, PM2.5, PM10, temperature, and humidity was deployed in a real residential setting to illustrate the proposed approach. To enable semantic integration within BIM workflows, a structured classification system, AllBIMclass, was developed. It provides dedicated hierarchical codes for environmental sensors, defined by monitored parameters, installation location (indoor, outdoor, or mixed), power supply, and data handling mode. The pilot experience demonstrated how sensors can be registered, classified, and linked to BIM models, supporting data visualisation and basic management tasks. AllBIMclass is available in Revit 2026 (version 26.6.4.409, build 20250227_1515, 64-bit) (TXT) and Archicad 28 (version 28.0.0, build 3001, x86–64-bit) (XML) formats and is fully compatible with IFC schemas. Although the framework has not yet been applied to large-scale projects, its components are technically operational and ready for implementation. This research contributes to bridging the gap between environmental monitoring and digital construction workflows, paving the way for integration into digital twins, smart buildings, and sustainable infrastructure systems. Full article
(This article belongs to the Special Issue Advances in BIM-Based Architecture and Civil Infrastructure Systems)
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22 pages, 5652 KB  
Article
Building Energy Assessment of Thermal and Electrical Properties for Compact Cities: Case Study of a Multi-Purpose Building in South Korea
by Jaeho Lee and Jaewan Suh
Buildings 2025, 15(17), 3023; https://doi.org/10.3390/buildings15173023 - 25 Aug 2025
Viewed by 1035
Abstract
This study conducts a simulation-based assessment of a recently commissioned office building in the Republic of Korea, representing a typical public office facility. The building was modeled using EnergyPlus 23.1.0 after construction, although no validation was performed due to the absence of metered [...] Read more.
This study conducts a simulation-based assessment of a recently commissioned office building in the Republic of Korea, representing a typical public office facility. The building was modeled using EnergyPlus 23.1.0 after construction, although no validation was performed due to the absence of metered consumption data. Previous approaches relying on simplified methods such as the Radiant Time Series (RTS), which neglect dynamic building behavior, have often led to overestimated cooling and heating loads. This has emerged as a major obstacle in designing energy-efficient buildings within the context of compact and smart cities pursuing carbon neutrality. Consequently, the trend in building performance analysis is shifting toward dynamic simulations and digital twin-based design methodologies. Furthermore, electrification of buildings without adequate thermal load assessment may also contribute to overdesign, irrespective of urban environmental characteristics. From an urban planning standpoint, there is a growing need for performance criteria that reflect occupant behavior and actual usage patterns. However, dynamics-based building studies remain scarce in the Republic of Korea. In this context, the present study demonstrates that passive design strategies, implemented through systematic changes in envelope materials, HVAC operational standards, and compliance with ASHRAE 90.1 criteria, can significantly enhance thermal comfort and indoor air quality. The simulation results show that energy consumption can be reduced by over 36.21% without compromising occupant health or comfort. These findings underscore the importance of thermal load understanding prior to electrification and highlight the potential of LEED-aligned passive strategies for achieving high-performance, low-energy buildings. Full article
(This article belongs to the Special Issue Study on Building Energy Efficiency Related to Simulation Models)
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32 pages, 11164 KB  
Article
Evaluation of Environmental Factors Influencing Photovoltaic System Efficiency Under Real-World Conditions
by Krzysztof Pytel, Wiktor Hudy, Roman Filipek, Malgorzata Piaskowska-Silarska, Jana Depešová, Robert Sito, Ewa Janiszewska, Izabela Sieradzka and Krzysztof Sulkowski
Energies 2025, 18(8), 2113; https://doi.org/10.3390/en18082113 - 19 Apr 2025
Cited by 1 | Viewed by 1101
Abstract
The study addresses the impact of selected environmental factors on the energy production of photovoltaic systems under real outdoor conditions, with particular emphasis on the application of evolutionary computation techniques. The experiment was carried out on a dedicated test stand, where measurements were [...] Read more.
The study addresses the impact of selected environmental factors on the energy production of photovoltaic systems under real outdoor conditions, with particular emphasis on the application of evolutionary computation techniques. The experiment was carried out on a dedicated test stand, where measurements were made under natural environmental conditions. Parameters such as solar irradiance, wind speed, temperature, air pollution, and obtained PV power were continuously recorded. Initial correlation analysis using Pearson and Spearman coefficients confirmed associations between environmental factors and power output, especially solar irradiance. In order to advance the analysis beyond conventional methods, a linear regression model was developed in which the model weights were optimized using evolutionary algorithms, allowing for a more robust assessment of the contribution of each parameter. The results showed that solar irradiance accounted for 97.79% of the variance in photovoltaic power, while temperature (0.95%), air pollution (0.72%), and wind speed (0.54%) had significantly lower impacts. The implementation of evolutionary algorithms represents a novel approach in this context and has proven to be effective in quantifying environmental influence under complex real-world conditions. Furthermore, the findings highlight the indirect role of air pollution in attenuating irradiance and reducing system efficiency. These insights provide a foundation for the development of adaptive control strategies and predictive models to optimize the performance of the photovoltaic system in dynamic environmental settings. Full article
(This article belongs to the Collection Energy Efficiency and Environmental Issues)
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18 pages, 5349 KB  
Article
Integrating Cold Thermal Energy Storage for Air Conditioning Demand in a CO2 Refrigeration System at a Supermarket
by Davide Tommasini, Håkon Selvnes and Armin Hafner
Energies 2024, 17(23), 5923; https://doi.org/10.3390/en17235923 - 26 Nov 2024
Cited by 2 | Viewed by 2262
Abstract
A common configuration for transcritical CO2 booster systems in supermarkets involves air conditioning (AC) supplied by cooling a water-glycol circuit. The design capacity of the refrigeration unit must handle all refrigeration loads and the AC load during the hottest summer day, leading [...] Read more.
A common configuration for transcritical CO2 booster systems in supermarkets involves air conditioning (AC) supplied by cooling a water-glycol circuit. The design capacity of the refrigeration unit must handle all refrigeration loads and the AC load during the hottest summer day, leading to overcapacity and part-load operation for most of the year. A proposed design for implementing cold thermal energy storage (CTES) dedicated to AC demand in a supermarket located in the Oslo region is modeled in the object-oriented language Modelica. Simulation results demonstrate an electricity peak power reduction of up to 32.33%. Even though energy savings are not the primary objective of this project, they are achieved by producing and storing energy when the outdoor temperature is lower, and the coefficient of performance (COP) of the system is higher. The energy savings can reach up to 11.8%. Finally, the economic benefits of the system are assessed under the spot pricing system, revealing potential electricity cost savings of up to 12.56%. Full article
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18 pages, 3598 KB  
Article
The Application of GPS-Based Friend/Foe Localization and Identification to Enhance Security in Restricted Areas
by Lukas Chruszczyk, Damian E. Grzechca and Krzysztof Tokarz
Sensors 2024, 24(16), 5208; https://doi.org/10.3390/s24165208 - 12 Aug 2024
Viewed by 1865
Abstract
This paper is devoted to the application of object localization and identification with information combined from a radar system and a dedicated portable/mobile electronic device equipped with a global positioning system (GPS) receiver. This device is able to provide object’s (staff member, and [...] Read more.
This paper is devoted to the application of object localization and identification with information combined from a radar system and a dedicated portable/mobile electronic device equipped with a global positioning system (GPS) receiver. This device is able to provide object’s (staff member, and staff vehicle) rough location and identification. Such systems are required in very restrictive security areas like airports (e.g., open-air area and apron). Currently, the outdoor area of the airport is typically protected by a surveillance system operated by security guards. Surveillance systems are composed of different sensors, video and infrared cameras, and microwave radars. The sheer number of events generated via the system can lead to fatigue among staff, potentially resulting in the omission of critical events. To address this issue, we propose an electronic system equipped with a wireless module and a GPS module. This approach enables automatic identification of objects through the fusion of data from two independent systems (GPS and radar). The radar system is capable of precisely localizing and tracking objects, while the described system is able to identify registered objects. This paper contains a description of the subsystems of a portable/mobile electronic device. The fusion of information from the proposed system (rough location and identification) with the precise location obtained from short-range radar is intended to reduce the number of false alerts in the surveillance system. Full article
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73 pages, 7689 KB  
Review
Wearable Nano-Based Gas Sensors for Environmental Monitoring and Encountered Challenges in Optimization
by Sara Hooshmand, Panagiotis Kassanos, Meysam Keshavarz, Pelin Duru, Cemre Irmak Kayalan, İzzet Kale and Mustafa Kemal Bayazit
Sensors 2023, 23(20), 8648; https://doi.org/10.3390/s23208648 - 23 Oct 2023
Cited by 66 | Viewed by 16873
Abstract
With a rising emphasis on public safety and quality of life, there is an urgent need to ensure optimal air quality, both indoors and outdoors. Detecting toxic gaseous compounds plays a pivotal role in shaping our sustainable future. This review aims to elucidate [...] Read more.
With a rising emphasis on public safety and quality of life, there is an urgent need to ensure optimal air quality, both indoors and outdoors. Detecting toxic gaseous compounds plays a pivotal role in shaping our sustainable future. This review aims to elucidate the advancements in smart wearable (nano)sensors for monitoring harmful gaseous pollutants, such as ammonia (NH3), nitric oxide (NO), nitrous oxide (N2O), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), hydrogen sulfide (H2S), sulfur dioxide (SO2), ozone (O3), hydrocarbons (CxHy), and hydrogen fluoride (HF). Differentiating this review from its predecessors, we shed light on the challenges faced in enhancing sensor performance and offer a deep dive into the evolution of sensing materials, wearable substrates, electrodes, and types of sensors. Noteworthy materials for robust detection systems encompass 2D nanostructures, carbon nanomaterials, conducting polymers, nanohybrids, and metal oxide semiconductors. A dedicated section dissects the significance of circuit integration, miniaturization, real-time sensing, repeatability, reusability, power efficiency, gas-sensitive material deposition, selectivity, sensitivity, stability, and response/recovery time, pinpointing gaps in the current knowledge and offering avenues for further research. To conclude, we provide insights and suggestions for the prospective trajectory of smart wearable nanosensors in addressing the extant challenges. Full article
(This article belongs to the Topic Advanced Nanomaterials for Sensing Applications)
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16 pages, 8271 KB  
Article
Design and Implementation of a Particulate Matter Measurement System for Energy-Efficient Searching of Air Pollution Sources Using a Multirotor Robot
by Grzegorz Suchanek, Roman Filipek and Andrzej Gołaś
Energies 2023, 16(7), 2959; https://doi.org/10.3390/en16072959 - 23 Mar 2023
Cited by 4 | Viewed by 2173
Abstract
Analyzing air pollutants is of key importance for the environmental protection goals. High concentrations of particulate matter (PM) have a particularly negative impact on human life and health. The use of an autonomous multirotor flying robot (drone) for the purposes of locating PM [...] Read more.
Analyzing air pollutants is of key importance for the environmental protection goals. High concentrations of particulate matter (PM) have a particularly negative impact on human life and health. The use of an autonomous multirotor flying robot (drone) for the purposes of locating PM sources requires the design of a dedicated measurement system from scratch. The aim of this study was to make the most important design decision, which is the correct localization of the inlet of the measurement system, taking into account disturbances in the flow field caused by the rotors. To achieve this, a computational model was built with the use of a finite-volume method in Ansys Fluent software. Based on its results, a novel criterion was proposed and applied. In addition to the trivial position outside the rotors on the extended arm, it gave the second location in the space limited by the rotors below the robot. Finally, a robot prototype was built, and a series of verification experiments were carried out, first indoors and then outdoors, at different levels of ambient PM concentrations with and without a pollution source. The field results were compiled as histograms and scatter plots and clearly demonstrated the validity of the adopted criterion. The determination coefficient between measured concentrations showed a stronger relationship when the rotors were operating. Furthermore, in cases with a present pollution source, higher concentrations were observed around the internal sensor, making it more suitable for the studied application. Full article
(This article belongs to the Collection Energy Efficiency and Environmental Issues)
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24 pages, 3679 KB  
Article
Energy Analysis of Control Measures for Reducing Aerosol Transmission of COVID-19 in the Tourism Sector of the “Costa Daurada” Spain
by Dereje S. Ayou, Juan Prieto, Fahreza Ramadhan, Genaro González, Juan Antonio Duro and Alberto Coronas
Energies 2022, 15(3), 937; https://doi.org/10.3390/en15030937 - 27 Jan 2022
Cited by 1 | Viewed by 3184
Abstract
In this paper, the use of HVAC systems and non-HVAC control measures to reduce virus-laden bioaerosol exposure in a highly occupied indoor space is investigated. A simulation tool was used to model the fate and transport of bioaerosols in an indoor space in [...] Read more.
In this paper, the use of HVAC systems and non-HVAC control measures to reduce virus-laden bioaerosol exposure in a highly occupied indoor space is investigated. A simulation tool was used to model the fate and transport of bioaerosols in an indoor space in the hotel industry (bar or pub) with three types of HVAC system (central air handling system (CAHS), dedicated outdoor air system (DOAS), and wall unit system (WUS)). Non-HVAC control measures such as portable air cleaners (PAC) and local exhaust fans were considered. Occupant exposure was evaluated for 1 μm bioaerosols, which transport SARS-CoV-2, for 3 h/day of continuous source and exposure. The combined effects of ventilation (400 l/s of outdoor air), recirculated air filtration (90% efficacy), and a PAC with a capacity up to 900 m3/h mitigated the (normalized) integrated exposure of the occupant by 0.66 to 0.51 (CAHS) and 0.43 to 0.36 (DOAS). In the case of WUS, the normalized integrated exposure was reduced by up to 0.2 when the PAC with a capacity of up to 900 m3/h was used. The corresponding electricity consumed increased by 297.4 kWh/year (CAHS) and 482.7 kWh/year (DOAS), while for the WUS it increased by 197.1 kWh/year. Full article
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18 pages, 4855 KB  
Article
Improving Building Energy Performance Using Dual VAV Configuration Integrated with Dedicated Outdoor Air System
by Nabil Nassif and Iffat Ridwana
Buildings 2021, 11(10), 466; https://doi.org/10.3390/buildings11100466 - 12 Oct 2021
Cited by 6 | Viewed by 5726
Abstract
As building systems account for almost half of the total energy consumed by the building sector to provide space heating, cooling, and ventilation, efficiently designing these systems can be the key to energy conservation in buildings. Dual VAV systems with an effective control [...] Read more.
As building systems account for almost half of the total energy consumed by the building sector to provide space heating, cooling, and ventilation, efficiently designing these systems can be the key to energy conservation in buildings. Dual VAV systems with an effective control strategy can substantially reduce the energy consumption in buildings, providing a significant scope of further research on this system configuration. This paper proposes to utilize the warm air duct of the dual VAV system as a dedicated outdoor air (DOA) unit when no heating is required, which allows the cooling load to be effectively distributed between two ducts. A specific control sequence is proposed with different supply air temperature reset strategies to estimate the heating, cooling loads, and fan power energy consumption of the proposed system. A simple two-zone office building is taken as a preliminary case study to simulate the airflow rates and fan power of a single duct VAV and proposed dual VAV systems to illustrate the concept. Finally, a larger multi-zone office building is simulated to measure the annual heating, cooling loads, and fan power energy and compare the energy savings among the systems. The results show significant fan power reduction ranging from 1.7 to 9% and notable heating energy reduction up to 76.5% with a small amount of cooling load reduction varying from 0.76 to 2.56% depending on the different locations for the proposed dual VAV systems. Further energy savings from different supply air temperature reset strategies demonstrate the opportunity of employing them according to climates and case studies. The proposed dual VAV system proves to have the potential to be adapted in buildings for the purpose of sustainability and energy savings. Full article
(This article belongs to the Section Building Energy, Physics, Environment, and Systems)
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26 pages, 62368 KB  
Article
Energy Saving Quantitative Analysis of Passive, Active, and Renewable Technologies in Different Climate Zones
by Chul-Ho Kim, Min-Kyeong Park and Won-Hee Kang
Appl. Sci. 2021, 11(15), 7115; https://doi.org/10.3390/app11157115 - 31 Jul 2021
Cited by 7 | Viewed by 3922
Abstract
The purpose of this study was to provide a guideline for the selection of technologies suitable for ASHRAE international climate zones when designing high-performance buildings. In this study, high-performance technologies were grouped as passive, active, and renewable energy systems. Energy saving technologies comprising [...] Read more.
The purpose of this study was to provide a guideline for the selection of technologies suitable for ASHRAE international climate zones when designing high-performance buildings. In this study, high-performance technologies were grouped as passive, active, and renewable energy systems. Energy saving technologies comprising 15 cases were categorized into passive, active, and renewable energy systems. EnergyPlus v9.5.0 was used to analyze the contribution of each technology in reducing the primary energy consumption. The energy consumption of each system was analyzed in different climates (Incheon, New Delhi, Minneapolis, Berlin), and the detailed contributions to saving energy were evaluated. Even when the same technology is applied, the energy saving rate differs according to the climatic characteristics. Shading systems are passive systems that are more effective in hot regions. In addition, the variable air volume (VAV) system, combined VAV–energy recovery ventilation (ERV), and combined VAV–underfloor air distribution (UFAD) are active systems that can convert hot and humid outdoor temperatures to create comfortable indoor environments. In cold and cool regions, passive systems that prevent heat loss, such as high-R insulation walls and windows, are effective. Active systems that utilize outdoor air or ventilation include the combined VAV-economizer, the active chilled beam with dedicated outdoor air system (DOAS), and the combined VAV-ERV. For renewable energy systems, the ground source heat pump (GSHP) is more effective. Selecting energy saving technologies that are suitable for the surrounding environment, and selecting design strategies that are appropriate for a given climate, are very important for the design of high-performance buildings globally. Full article
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16 pages, 334 KB  
Conference Report
Policy Implications for Protecting Health from the Hazards of Fire Smoke. A Panel Discussion Report from the Workshop Landscape Fire Smoke: Protecting Health in an Era of Escalating Fire Risk
by Christine T. Cowie, Amanda J. Wheeler, Joy S. Tripovich, Ana Porta-Cubas, Martine Dennekamp, Sotiris Vardoulakis, Michele Goldman, Melissa Sweet, Penny Howard and Fay Johnston
Int. J. Environ. Res. Public Health 2021, 18(11), 5702; https://doi.org/10.3390/ijerph18115702 - 26 May 2021
Cited by 13 | Viewed by 4650
Abstract
Globally, and nationally in Australia, bushfires are expected to increase in frequency and intensity due to climate change. To date, protection of human health from fire smoke has largely relied on individual-level actions. Recent bushfires experienced during the Australian summer of 2019–2020 occurred [...] Read more.
Globally, and nationally in Australia, bushfires are expected to increase in frequency and intensity due to climate change. To date, protection of human health from fire smoke has largely relied on individual-level actions. Recent bushfires experienced during the Australian summer of 2019–2020 occurred over a prolonged period and encompassed far larger geographical areas than previously experienced, resulting in extreme levels of smoke for extended periods of time. This particular bushfire season resulted in highly challenging conditions, where many people were unable to protect themselves from smoke exposures. The Centre for Air pollution, energy and health Research (CAR), an Australian research centre, hosted a two-day symposium, Landscape Fire Smoke: Protecting health in an era of escalating fire risk, on 8 and 9 October 2020. One component of the symposium was a dedicated panel discussion where invited experts were asked to examine alternative policy settings for protecting health from fire smoke hazards with specific reference to interventions to minimise exposure, protection of outdoor workers, and current systems for communicating health risk. This paper documents the proceedings of the expert panel and participant discussion held during the workshop. Full article
21 pages, 3077 KB  
Article
Development of a Submillimetric GNSS-Based Distance Meter for Length Metrology
by Luis García-Asenjo, Sergio Baselga, Chris Atkins and Pascual Garrigues
Sensors 2021, 21(4), 1145; https://doi.org/10.3390/s21041145 - 6 Feb 2021
Cited by 15 | Viewed by 3235
Abstract
Absolute distance determination in the open air with an uncertainty of a few tenths of a millimetre is increasingly required in many applications that involve high precision geodetic metrology. No matter the technique used to measure, the resulting distances must be proven consistent [...] Read more.
Absolute distance determination in the open air with an uncertainty of a few tenths of a millimetre is increasingly required in many applications that involve high precision geodetic metrology. No matter the technique used to measure, the resulting distances must be proven consistent with the unit of length (SI-metre) as realized in the outdoor facilities traditionally used in length metrology, which are also known as calibration baselines of reference. The current calibration baselines of reference have distances in the range of 10 to 1000 m, but at present there is no solution on the market to provide distances with submillimetric precision in that range. Consequently, new techniques such as multi-wave interferometry, two-wave laser telemeters or laser trackers are being developed. A possible alternative to those sophisticated and expensive techniques is the use of widely used Global Navigation Satellite Systems (GNSS) in order to provide a GNSS-Based Distance Meter (GBDM). The use of a GBDM as a potential technique for length metrology has been thoroughly analysed in several European research projects by using the state-of-the-art geodetic software, such as Bernese 5.2, but no definite conclusions have been drawn and some metrological questions are considered still open. In this paper, we describe a dedicated approach to build up a submillimetric GBDM able to be applied in the current calibration baselines of reference, as well as possible methods to cope with the multipath error of the GNSS signals which is the major limitation for the practical uptaking of the technique in metrology. The accuracy of the proposed approach has been tested following the length metrology standards in four experiments carried out in the Universitat Politècnica de València (UPV). The results demonstrate that the proposed GBDM can provide an accuracy of a few tenths of a millimetre in the current calibration baselines of reference. Full article
(This article belongs to the Collection Multi-GNSS Precise Positioning and Applications)
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21 pages, 1229 KB  
Article
Experimental Investigation of the Air Exchange Effectiveness of Push-Pull Ventilation Devices
by Sven Auerswald, Carina Hörberg, Thibault Pflug, Jens Pfafferott, Constanze Bongs and Hans-Martin Henning
Energies 2020, 13(21), 5817; https://doi.org/10.3390/en13215817 - 6 Nov 2020
Cited by 5 | Viewed by 4039
Abstract
The increasing installation numbers of ventilation units in residential buildings are driven by legal objectives to improve their energy efficiency. The dimensioning of a ventilation system for nearly zero energy buildings is usually based on the air flow rate desired by the clients [...] Read more.
The increasing installation numbers of ventilation units in residential buildings are driven by legal objectives to improve their energy efficiency. The dimensioning of a ventilation system for nearly zero energy buildings is usually based on the air flow rate desired by the clients or requested by technical regulations. However, this does not necessarily lead to a system actually able to renew the air volume of the living space effectively. In recent years decentralised systems with an alternating operation mode and fairly good energy efficiencies entered the market and following question was raised: “Does this operation mode allow an efficient air renewal?” This question can be answered experimentally by performing a tracer gas analysis. In the presented study, a total of 15 preliminary tests are carried out in a climatic chamber representing a single room equipped with two push-pull devices. The tests include summer, winter and isothermal supply air conditions since this parameter variation is missing till now for push-pull devices. Further investigations are dedicated to the effect of thermal convection due to human heat dissipation on the room air flow. In dependence on these boundary conditions, the determined air exchange efficiency varies, lagging behind the expected range 0.5 < εa < 1 in almost all cases, indicating insufficient air exchange including short-circuiting. Local air exchange values suggest inhomogeneous air renewal depending on the distance to the indoor apertures as well as the temperature gradients between in- and outdoor. The tested measurement set-up is applicable for field measurements. Full article
(This article belongs to the Special Issue Energy Performance of Buildings)
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12 pages, 3367 KB  
Article
A Integrated Dedicated Outdoor Air System to Optimize Energy Saving
by Yew Khoy Chuah and Jun Jie Yang
Sustainability 2020, 12(3), 1051; https://doi.org/10.3390/su12031051 - 2 Feb 2020
Cited by 4 | Viewed by 5069
Abstract
Outdoor air supply is required to maintain good indoor air quality (IAQ). For tropical or subtropical regions, warm and humid outdoor air would cause excess air-conditioning energy use. This study has proposed an integrated dedicated outdoor air system (IDOAS), which integrates the enthalpy [...] Read more.
Outdoor air supply is required to maintain good indoor air quality (IAQ). For tropical or subtropical regions, warm and humid outdoor air would cause excess air-conditioning energy use. This study has proposed an integrated dedicated outdoor air system (IDOAS), which integrates the enthalpy exchange and outdoor air cooling into a unitary system. IDOAS could operate independently of central air-conditioning systems thus saving tremendous piping cost and energy needed to deliver chilled water to outdoor air unit in a conventional centralized system. An experimental unit of IDOAS was built to prove this novel concept. Enthalpy exchange efficiency was tested to be about 44%. The test results show that about 44% of energy needed to condition the outdoor air can be saved. A reverse Rankine refrigeration cycle was integrated to cool the outdoor air. Due to this integrated configuration, the air passing through the condenser would be at a lower temperature. The consequent lower refrigerant condensing temperature would improve the cooling cycle efficiency. The cooling coefficient of performance (COP) was improved by about 46%. In addition, the outdoor air could be conditioned to a lower humidity before being supplied to space, which would improve the thermal comfort. The test results of this novel IDOAS show that it could provide good air quality at lower energy use. Full article
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