Modeling of light pipes for the optimal disposition in buildings

A light pipe is an excellent solution to transport and distribute daylight into environments without or with little lighting, guaranteeing comfort inside the rooms. As stated in the literature, the evaluation of the performances of light pipes presents numerous complexities, making the work very difficult for technicians and designers. This study is aimed to present a methodology that is able to identify the potential of light pipes using indices such as daylight autonomy (DA), continuous daylight autonomy (DAc), and useful daylight illuminance (UDI). This paper presents an analysis of daylight obtained by several configurations of simple models of light pipes installed into a 5 7 5 m plant area room. All simulations are carried out in a DAYSIM environment, which allows calculating the annual availability of daylight based on a RADIANCE raytracer backward. Several daylight conditions were analyzed for different light pipe configurations, considering different pipe lengths and a variable number of light pipes. The light pipes are tested also in the horizontal position, for different orientations. The results of all the combinations were compared with the performances of a window with dimensions equal to 1/8 of the internal surface, which was in accordance with the minimum value to be guaranteed by the Italian Regulation (D.M. 5 July 1975 n. 190) for different orientations. The results indicated a difference in daylight distribution, showing a strong correlation between the percentage levels of DA and DAc with the length and number of pipes, during different periods of the year. The simulated model is strongly influenced by the aspect ratio (R = diameter/length). The results show that the illuminance levels decrease drastically, increasing the length

A new device hypothesis for water extraction from air and basic air condition system in developing countries

This work proposes a new device for air treatment with dehumidification and water recovery/storage, with possible mitigation of indoor environmental conditions. The system is based on Peltier cells coupled with a horizontal earth‐to‐air heat exchanger, it is proposed as an easy‐to-implement alternative to the heat pumps and air handling units currently used on the market, in terms of cost, ease of installation, and maintenance. The process provides the water collection from the cooling of warm‐humid air through a process that leads to condensation and water vapor separation. The airflow generated by a fan splits into two dual flows that lap the two surfaces of the Peltier cells, one flow laps the cold surfaces undergoing sensible, latent cooling with dehumidification; the other flow laps the hot surfaces and heats up. The airflow undergoes thermal pre‐treatment through the underground horizontal geothermal pipe that precedes the Peltier cells. In the water storage tank, which also works as a mixing chamber, the two air streams are mixed to regulate the outlet temperature. The system can be stand‐alone if equipped with a photovoltaic panel and a micro wind turbine, able to be used in places where electricity is absent. The system, with different configurations, is modeled in the African city Kigali, in Rwanda

Experimental analysis of the rising damp by the comparison between different geometrical configurations: mono and multi-blocks of carparo and pietra leccese

The rising damp is the principal cause of the deterioration of the masonry in the existing constructions. Since carparo and pietra leccese are the most used materials in southern Italy, this study aims to underline the trend of the rising damp for the two building materials considering mono and multi- block configurations. All analyzes were developed with and without the influence of the Domodry® system

Energy Independence of a Small Office Community Powered by Photovoltaic-Wind Hybrid Systems in Widely Different Climates

Hybrid renewable energy systems are an optimal solution for small energy communities’ energy supply. One of the critical issues is the strong correlation of these systems with outdoor climatic conditions. The goal is to make local communities increasingly energy independent. To this end, an in-depth analysis of the behaviour of hybrid photovoltaic (PV)–wind systems powering small office communities in 48 locations around the world characterized by widely varying climates was conducted. System sizes, assumed to be stand-alone or grid-connected, were varied, for a total of 343 system power configurations. Highest satisfied load fraction (SLF) values are obtained with a significant predominance of PV over wind; the trend is more pronounced in dry and continental climates (zones B and D according to the Köppen climate classification). The utilization factor (UF) values of 1 are rarely reached and never in the wind-only or PV-only configurations. In all climates, the grid energy interaction factor (GEIF) values of zero are never reached but come very close. The benefit-cost ratio (BCR) of grid-connected systems is significantly higher than stand-alone systems

An Integer Linear Programming approach to minimize the cost of the refurbishment of a façade to improve the energy efficiency of a building

[EN] Buildings account 40% of the EU's total energy consumption. Therefore, they represent a key potential source of energy savings to fight, among others, against climate change. Furthermore, around 54% of the buildings in Spain date back before 1980, when no thermal regulation was available. The refurbishment of a façade of an old building is usually the most effective way to improve its energy efficiency, by adding layers to the external envelope in order to reduce its thermal transmittance. This paper deals with the problem of minimizing costs for the thermal refurbishment of a façade with thickness and thermal ransmittance bounds and with an intervention both on the opaque part (wall) and the transparent part (windows). Among thousands, even millions of combinations of materials and thicknesses for the different layers to be added to the opaque part, types of frame, and combinations of glasses and air chambers for the transparent part, the aim is to choose the one that minimizes the cost without violating any restriction imposed to the thermal refurbishment, in particular the current energy efficiency regulations in the zone. To optimally solve this problem, it will be modelled as an Integer Linear Programming problem with binary variables. The case study will be Building 1B of the School for Building Engineering of the Polytechnic University of Valencia, Spain. It was built in the late 1960s and has had a very inefficient energy consumption record. The optimal solution will be found among more than 6 million feasible solutions.Salandin, A.; Soler Fernández, D.; Bevivino, M. (2020). 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A., Olofsson, T., & Ödlund (former Trygg), L. (2018). Environmental impact of energy refurbishment of buildings within different district heating systems. Applied Energy, 227, 231-238. doi:10.1016/j.apenergy.2017.07.022Mickaitytė, A., Zavadskas, E. K., Kaklauskas, A., & Tupėnaitė, L. (2008). THE CONCEPT MODEL OF SUSTAINABLE BUILDINGS REFURBISHMENT. International Journal of Strategic Property Management, 12(1), 53-68. doi:10.3846/1648-715x.2008.12.53-68Passer, A., Ouellet-Plamondon, C., Kenneally, P., John, V., & Habert, G. (2016). The impact of future scenarios on building refurbishment strategies towards plus energy buildings. Energy and Buildings, 124, 153-163. doi:10.1016/j.enbuild.2016.04.008Energy efficiency in buildings.https://www.buildingtechnologies.siemens.com/bt/global/en/building‐knowledge/pages/energy‐efficiency.aspx(accessed 27.12.2018).Baglivo, C., & Congedo, P. M. (2015). Design method of high performance precast external walls for warm climate by multi-objective optimization analysis. Energy, 90, 1645-1661. doi:10.1016/j.energy.2015.06.132Baglivo, C., Congedo, P. M., D’Agostino, D., & Zacà, I. (2015). Cost-optimal analysis and technical comparison between standard and high efficient mono-residential buildings in a warm climate. Energy, 83, 560-575. doi:10.1016/j.energy.2015.02.062Corgnati, S. P., Fabrizio, E., Filippi, M., & Monetti, V. (2013). Reference buildings for cost optimal analysis: Method of definition and application. Applied Energy, 102, 983-993. doi:10.1016/j.apenergy.2012.06.001U‐values in Europe.https://www.eurima.org/u‐values‐in‐europe(accessed 27.12.2018).CTE.Código Técnico de la Edificación (Spanish Technical Building Act). Documento Básico de Ahorro de Energía (Basic Document for Energy Saving). Version of 2013 with comments of 2016.http://www.codigotecnico.org/images/stories/pdf/ahorroEnergia/DccHE.pdf(accessed 27.12.2018).Sherali, H. D., & Driscoll, P. J. (2000). Evolution and state-of-the-art in integer programming. Journal of Computational and Applied Mathematics, 124(1-2), 319-340. doi:10.1016/s0377-0427(00)00431-3Kurnitski, J., Saari, A., Kalamees, T., Vuolle, M., Niemelä, J., & Tark, T. (2013). Cost optimal and nearly zero energy performance requirements for buildings in Estonia. Estonian Journal of Engineering, 19(3), 183. doi:10.3176/eng.2013.3.02Congedo, P. M., Baglivo, C., D’Agostino, D., & Zacà, I. (2015). Cost-optimal design for nearly zero energy office buildings located in warm climates. Energy, 91, 967-982. doi:10.1016/j.energy.2015.08.078Sambou, V., Lartigue, B., Monchoux, F., & Adj, M. (2009). Thermal optimization of multilayered walls using genetic algorithms. Energy and Buildings, 41(10), 1031-1036. doi:10.1016/j.enbuild.2009.05.007Di Perna, C., Stazi, F., Casalena, A. U., & D’Orazio, M. (2011). Influence of the internal inertia of the building envelope on summertime comfort in buildings with high internal heat loads. Energy and Buildings, 43(1), 200-206. doi:10.1016/j.enbuild.2010.09.007Privitera, G., Day, A. R., Dhesi, G., & Long, D. (2011). Optimising the installation costs of renewable energy technologies in buildings: A Linear Programming approach. Energy and Buildings, 43(4), 838-843. doi:10.1016/j.enbuild.2010.12.003Ashouri, A., Fux, S. S., Benz, M. J., & Guzzella, L. (2013). Optimal design and operation of building services using mixed-integer linear programming techniques. Energy, 59, 365-376. doi:10.1016/j.energy.2013.06.053Lindberg, K. B., Doorman, G., Fischer, D., Korpås, M., Ånestad, A., & Sartori, I. (2016). Methodology for optimal energy system design of Zero Energy Buildings using mixed-integer linear programming. 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Thermal Modeling of a Historical Building Wall: Using Long-Term Monitoring Data to Understand the Reliability and the Robustness of Numerical Simulations

Thermal modeling of building components plays a crucial role in designing energy efficiency measures, assessing living comfort, and preventing building damages. The accuracy of the modeling process strongly depends on the reliability of the physical models and the correct selection of input parameters, especially for historic buildings where uncertainties on wall composition and material properties are higher. This work evaluates the reliability of building thermal modeling and identifies the input parameters that most affect the simulation results. A monitoring system is applied to a historic building wall to measure the temperature profile. The long-term dataset is compared with the result of a simulation model. A sensitivity analysis is applied for the determination of the influential input parameters. A two-step optimization is performed to calibrate the numerical model: the first optimization step is based on an optimized selection of the database materials, while the second optimization step uses a particle swarm algorithm. The results indicate that the output of the simulation model is largely influenced by the coefficients describing the coupling with the boundary conditions and by the thermal conductivities of the materials. Very good results are obtained already after the first optimization step ((Formula presented.) while the second optimization step improves further the agreement ((Formula presented.). The parameter values reported in the datasheets do not match those found through optimization. Even with extensive optimization using an algorithm, starting with monitoring data is insufficient to identify material parameter values

Definition of a Protocol for the Experimental Monitoring of Rising Damp in Three Different Masonry Models with Tuff, Carparo, and Lecce Stone

This work presents a new protocol for monitoring rising damp, which is applied to three masonry models made of tuff, carparo, and Lecce stone. First, the physical characteristics of each stone were derived in the laboratory, which included porosity, imbibition, drying index, permeability, capillarity, and sorptivity. In this case, the protocol provided three columns, one for each material, consisting of five blocks. A layer of cotton tissue was interposed between columned blocks to simulate the hygroscopic behavior of a mortar, allowing a quick disassembly and reassembly of the multiblock columns for a quick weighing. The bottoms of the columns were immersed in water to a level of about three centimeters, providing a constant replenishment for the phenomena of evaporation and rising in the stone. The maximum height achieved by the rising damp depends on the characteristics of the building materials, i.e., the amount and size of pores, pore connectivity, etc. Since these materials have different physical characteristics, the objective was to quantify the rising moisture level of the three materials tested, block by block, in a controlled indoor microclimate environment. The three columns were periodically weighed, the quantity of collected water was evaluated, and a thermographic survey was performed. The results show that at the end of the test, the highest level of rising damp is reached by tuff with a height of 43 cm, followed by Lecce stone and carparo with a height of 40 cm and 21 cm, respectively. The innovation of this study is the proposal of a new flexible and easy‐to‐apply method for monitoring this phenomenon. It gives clear and numerically comparable results. Moreover, it is applicable to any type of stone, allowing the user to evaluate both the existing state and different design solutions

Eco-Sustainable Energy Production in Healthcare: Trends and Challenges in Renewable Energy Systems

The shift from fossil fuels to renewable energy systems represents a pivotal step toward the realization of a sustainable society. This study aims to analyze representative scientific literature on eco-sustainable energy production in the healthcare sector, particularly in hospitals. Given hospitals’ substantial electricity consumption, the adoption of renewable energy offers a reliable, low-CO2 emission solution. The COVID-19 pandemic has underscored the urgency for energy-efficient and environmentally-responsible approaches. This brief review analyzes the development of experimental, simulation, and optimization projects for sustainable energy production in healthcare facilities. The analysis reveals trends and challenges in renewable energy systems, offering valuable insights into the potential of eco-sustainable solutions in the healthcare sector. The findings indicate that hydrogen storage systems are consistently coupled with photovoltaic panels or solar collectors, but only 14% of the analyzed studies explore this potential within hospital settings. Hybrid renewable energy systems (HRES) could be used to meet the energy demands of healthcare centers and hospitals. However, the integration of HRES in hospitals and medical buildings is understudied

Antimicrobial Activity in the Pallial Cavity Fluids of the Oyster Crassostrea virginica (Gmelin) from a Highly Impacted Harbor in Western Long Island Sound

Fluid and its associatedmucus from the pallial (mantle) cavity of eastern oysters Crassostrea virginica (Gmelin) from Black RockHarbor, Bridgeport, Connecticut, inhibited growth of both Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Serratia marcescens, and Vibrio parahaemolyticus) bacteria in antimicrobial assays. In the presence of oyster fluid, E. coli resulted in significant reduction in growth after 26 h. Soluble lysozyme activity in pallial cavity fluid of oysters collected in the fall was 3 times greater than that measured in combined winter—spring—summer samples (P = 0.0008). During the course of the study, copper concentrations in pallial cavity fluid ranged from 0.60–2.49 ppm and zinc concentrations ranged from 9.7–61.0 ppm. Copper concentrations remained relatively constant throughout the study; the highest zinc concentrations were recorded in the fall. Fall antimicrobial assays showed heightened antimicrobial activity compared with the spring, which may be the result of increased lysozyme activity and higher zinc concentrations present in the pallial cavity fluid at that time of year. Results of this study suggest that pallial cavity fluid and its associated mucus likely serve an important role in defense-related functions as the first line of defense against infections from environmental pathogens in Crassostrea virginica