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This paper presents the results of seismic connection testing and finite element analyses (FEA) on the slenderness limitations of steel H-beams in special moment-frame (SMF) connections. The effectiveness of FEA models was first validated by the full-scale testing of a reduced-web-section (RWS) connection, and a post-earthquake bolted-web-welded-flange (BWWF) connection. FEA simulations were then performed to study the beam section properties and seismic connection performance. The result shows that if a H-beam has a compact section, the adopted connection will develop strength and ductility meeting the AISC seismic requirements, even though the plastic section modulus ratio between the beam flanges and whole section is less than 70%. The result also suggests the effectiveness of adding a web opening to a BWWF connection. These findings call for a re-examination of the requirements of highly ductile members in SMF connections. • The slenderness limitations and Z f / Z ratios are examined for steel H-beams for SMF connections. • The result suggests the effectiveness of adding a web opening to a BWWF connection. • The findings call for a re-examination of the requirements of highly ductile members in SMF connections. [ABSTRACT FROM AUTHOR]

Highlights: [•] We integrated architectural design, a heat flow mechanism, and hot water generation with a wall. [•] We proposed an innovative curtain-wall-integrated solar heater. [•] The heat transfer performance was investigated experimentally. [•] The system-wide energy harvest ratio of the test cell is between 0.45 and 0.78. [ABSTRACT FROM AUTHOR]

Highlights: [•] mPCM and Al honeycomb structure were combined to construct a wallboard prototype. [•] Thermal performance of the prototype was investigated experimentally. [•] The temperatures within the whole mPCM gradually and uniformly increased. [•] The PCM latent heat of the prototype can achieve a lower surface temperature. [•] A correlation of the effective thermal protection duration of the prototype was proposed. [Copyright &y& Elsevier]

In energy storage, energy transfer and thermal management applications, phase change material (PCM) nanoemulsions are promising; however, supercooling has always been an important issue in the research and application of PCMs. When supercooling occurs, the efficiency of energy storage applications may possibly be reduced. In this study, n-octadecane and n-eicosane (as core materials), and nonionic surfactants (hydrophile-lipophile balance value = 8) were used to prepare n-octadecane and n-eicosane emulsions with a mass concentration of 1–9%. The effects of particle size and operation temperature on emulsion viscosity were investigated, and the relationships between supercooling and the PCM particle size, PCM concentration and process cooling rates were analyzed. The results showed that small PCM particles could form a 2nd freezing point far from the melting point, resulting in a large supercooling degree. As the process cooling rates increased, the supercooling became more pronounced. However, when the high-concentration emulsion was mainly composed of small particles and subjected to low cooling rates, the concentration effect was significant, thereby decreasing the supercooling effect. [ABSTRACT FROM AUTHOR]

Abstract: According to the case-based reasoning of natural ventilation designs in recommended Green Buildings, an investigated model space was proposed in this study. FDS simulations and full-scale experiments were carried out to measure the impact of natural ventilation conditions and the installation of a natural ventilation shaft on smoke layer descent during different fire scenarios. The feasibility of using the N-percentage rule to determine the fire smoke layer height in a naturally ventilated space was also investigated. In a non-fire room, the smoke descent curve determined from the FDS simulated temperatures is consistent with the experimentally measured temperatures and visual observation of the smoke layer. However, the thermocouples in the fire room are affected by direct burning and fire radiation, and the experimentally measured temperatures cannot be used to determine the smoke height. Under these conditions, FDS simulations can be used to compensate for the lack of experimental measurements. In fire scenarios without outdoor winds blowing into the building's interior, FDS simulations can reliably model the fire smoke layer height. When outdoor air blows into the interior, it causes the smoke layer temperature to become unstable. Thus, the temperature will not be thermally stratified, and the use of the N-percentage rule is not recommended. [Copyright &y& Elsevier]

Abstract: In a Photovoltaic (PV) system, heat is generated by an operating diode. Because DC combiner boxes are waterproof, dustproof, air tight and made of heat-insulating material, thermal energy is easily accumulated, affecting the performance and safety of power cables and other electronic components near the diodes in the DC combiner box. This study utilizes a heat pipe as a channel for heat dissipation to conduct the heat out of a DC combiner box without destroying the air-tightness of the box. An existing DC combiner box was improved upon using this method of heat dissipation. The measured heat flow and temperature demonstrate that the proposed method is feasible. The influence of the condensation section temperature on the maximum heat transfer of the heat pipe was also investigated by experiment. The maximum heat transfer rate of the heat pipe was found to increase with the condensation section temperature of the heat pipe. When the condensation temperature was 20°C, 30°C and 40°C, the maximum heat transfer rate of the heat pipe was 21.6W, 29.6W and 39.7W, respectively. [Copyright &y& Elsevier]

Abstract: In the application of energy storage and thermal environmental control, PCM (Phase Change Material) is a very promising material choice. This study incorporated mPCM (micro-encapsulated PCM) into gypsum to make mPCM gypsum board and then investigated the physical properties, heat transfer and thermal storage behaviour. The major control parameters are wall temperatures and the weight percentages of mPCM added to the gypsum boards. A melting fraction correlation, reduced from our test data and based on Stefan number (Ste), subcooling (Sb) and Fourier number, is proposed. It shows that case with a higher Ste or Sb can have a higher heat transfer through the hot wall. Thermal storage behaviour of mPCM gypsum boards is then analyzed. [Copyright &y& Elsevier]

Abstract: Due to the widespread aquaculture at coastal area in Taiwan and high wind power potential in the sites, it is worthy to carry out the technical potential assessments of small-scale wind power system used for aquaculture in Taiwan. The present work analyzed wind power potential, described the practical installation, measured the actual energy output, verified the reliability of the energy output estimation method and elucidated important considerations associated with the use of this estimation method. The relationship between the actual energy generated and the wind speed characteristics were thus introduced. The power quality produced by a small-scale wind power generator was also evaluated. [Copyright &y& Elsevier]

Abstract: In order to respond the suggestions made in the previous works, such as (1) improving the design of the rooftop ventilator commonly used in Taiwan, (2) making the “push–pull” airflow model in the ventilation duct effective for the bathroom ventilation and (3) combining the energy demands of the ventilator with renewable energy to reduce energy consumption, this study develops a prototype of the rooftop turbine ventilator powered by hybrid wind and photovoltaic energy. A low-speed wind tunnel experiment is performed to investigate the prototype''s ventilation performance. The experimental results indicate installing an inner fan at low outdoor wind speed (0 and 5m/s) increases the ventilation rate. The ventilation rate was not improved by installing an inner fan at a high outdoor wind speed. A rated rotation speed close to 1500rpm is highly recommended when installing the inner fan. This study also introduces the general application modes of the proposed ventilator, and their electricity specifications. [Copyright &y& Elsevier]

Turbine ventilator is an equipment that uses natural wind force to bring out the rotation of the turbine and creates a negative pressure at the down-stream end of the pipeline to exhaust airflow. The form and designing concept are quite simple, yet it is ideal in practicality. Turbine ventilators are widely installed in Taiwan to enhance building ventilation (especially with spaces like bathrooms and kitchens where negative pressure is highly demanded) and the ventilation of factories. Theoretically, the proper combination of turbine ventilator and natural ventilation will help tremendously the indoor air quality while it will also decrease the reliance on air-conditioning and thus reduce the energy consummation. It is indeed a field of environmental design engineering that demands profound research.To acquire the common operation mode of the application of ventilators in Taiwan and the ventilation they induce, we use low-speed tunnel experiment to conduct a variety of tests on different styles of ventilators. And the results show that it is indeed helpful to increase ventilation with the installation of ventilators. The bigger the ventilator is with inner vanes, the better ventilation is guaranteed. However, the size (0.5 m/0.36 m) of the turbine ventilators and the availability of inner vanes do not mark significant differences in the ventilation rate induced. [Copyright &y& Elsevier]

A numerical study that uses the finite difference method to model the fluid flow and heat transfer of a rectangular natural circulation loop that contains phase change material (PCM) suspensions is presented to investigate how geometric parameters affect the thermal performance. Parametric simulations were performed using different geometrical parameters in the following ranges: the dimensionless length of the heated section = 0.4–1; the relative elevation of the cooled section compared with the heated section = 0.5–2; and the aspect ratio of the loop = 0.25–1. The results determine the important geometric parameters that affect the heat transfer performance of the loop with the PCM suspension. In several of the geometric configurations, the heat transfer performance of the loop is significantly affected by the latent heat contribution associated with the melting/freezing of the PCM particles. [ABSTRACT FROM PUBLISHER]

This paper considers a thermal phase change actuator filled with a solid–liquid phase change material (PCM), in which its ceiling wall can be thermally activated to move as a result of the volumetric changes associated with thermally induced melting and freezing processes of the PCM contained. Specifically, the present study aims to explore experimentally the dynamic response characteristics of the actuator’s movable wall during the melting process of a paraffin (n-Octadecane) as the PCM filled in a rectangular container. Melting experiments for the phase change actuator heated laterally at various isothermal wall temperatures with the solid PCM filled at different initial subcooling temperatures below its melting point have been undertaken to examine the melting heat transfer characteristics as well as the displacement behavior of its movable wall. The experimental results obtained reveal clearly that the melting progress of the PCM within the actuator has a dominant bearing on the induced moving speed and thus the total displacement of its movable wall. Moreover, the subcooling condition for the solid PCM filled in the actuator during the melting process may give rise to significant time lag for its thermally driven response, hence increasing the total time required for the solid PCM to be fully melted. [ABSTRACT FROM AUTHOR]

In this study, a water-saturated microencapsulated phase change material (MEPCM) layer was attached to the back of a photovoltaic (PV) panel to form a MEPCM-PV module that floats on the water surface. Subsequently, numerical simulations were used to analyze the capabilities of this module for controlling the PV panel temperature and power generation efficiency during daylight according to the local summer climatic conditions (including air temperature, sky temperature, wind speed, solar irradiation, water temperature, and water flow rate). The melting point (30 and 28 °C) and thickness (5 and 3 cm) of the MEPCM were investigated. The power generation efficiency improved when a 5 cm water-saturated MEPCM with a melting point of 30 °C was attached to the back of the PV panel. [ABSTRACT FROM AUTHOR]

In this study, the heat transfer characteristics of Al 2 O 3 –water nanofluid were investigated experimentally in a rectangular natural circulation loop of 402 mm in height and 205 mm in width. The 120-mm-long heated section and 155-mm-long cooling section in the loop were constructed with mini-channel heat exchangers. The nanometer-sized particles of alumina (Al 2 O 3 ) were dispersed in pure water (the base fluid) to form the alumina–water nanofluid with mass fractions in the range of 0.1–1 wt.%. The results clearly indicate that Al 2 O 3 –water nanofluid can markedly enhance the heat-transfer performance of the natural circulation loop considered. The average heat-transfer effectiveness at the heating and cooling sections were approximately 3.5–22% and 9.5–62% respectively. [ABSTRACT FROM AUTHOR]

In this study, a microencapsulated phase change material (MEPCM) layer was attached to the back of a photovoltaic (PV) panel to form a MEPCM-PV module that floated on the water surface. Subsequently, numerical simulations were used to determine if this PV module could effectively store solar radiation energy at the bottom of the MEPCM layer and release it to the underneath water at night during the winter season. This analysis was based on local winter climatic conditions, such as air temperature, sky temperature, wind speed, solar irradiation, water temperature, and water flow rate. The investigated parameters included the melting point (18 and 17 °C) and thickness (5 and 3 cm) of the MEPCM. The PV treated with a 5 cm/ melting point 17 °C MEPCM layer effectively released the energy that was stored during the daytime to the water. This energy release provided a local high temperature area for the aqua farms during cold weather and reduced the cold damage. [ABSTRACT FROM AUTHOR]

In this study, a numerical simulation is performed to explore oscillatory natural convection in a square enclosure with a phase change material (PCM) suspension using the implicit finite difference method. The following parameters are considered: aspect ratio of the physical model = 1; ratio of the buoyancies caused by temperature and concentration gradients = 1; Rayleigh number = 103-106; initial mass fraction (or concentration) of PCM particles = 0–0.1; Stefan number = 0.005–0.1; and subcooling factor = 0–1.0. The results show that high Rayleigh numbers can easily cause oscillations in the flow field and temperature distribution. However, even under low Rayleigh number conditions, when the initial mass fraction or subcooling is increased or the Stefan number is decreased, oscillations occur. • Heat transfer in an enclosure with PCM suspension was numerically investigated. • Oscillatory natural convection phenomena are found. • High Rayleigh numbers can easily cause the oscillations in the flow and temperature. • High initial mass fraction or subcooling can cause, even under low Rayleigh numbers. • Low Stefan numbers cause too, under low Rayleigh numbers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Water-saturated MEPCM layers were used as the thermal management medium for PV modules. [•] Their thermal and electrical performances were explored via CFD technique. [•] Incorporating the water-saturated MEPCM can improve the performances. [•] A MEPCM melting point and layer thicknesses was recommended for practical use. [ABSTRACT FROM AUTHOR]

This study is primarily focused on the influence of horizontal longitudinal vibrations and the condensation section temperature on the heat transfer performance of a grooved cylindrical copper heat pipe, with a length of 600 mm and an outer diameter of 8 mm. Longitudinal vibrations with frequencies of 3, 4, 5, 6, and 9 Hz and amplitudes of 2.8, 5, 10, 15, 20, and 25 mm, which would give accelerations in the range of 0.1–1.01 g, were experimentally tested. The condensation section temperature was set at 20, 30, or 40°C. A heating jacket and a cooling sleeve were installed at the evaporation and condensation sections of the test cell to mimic a constant heat flux and a constant temperature boundary, respectively. When the heat pipe started to vibrate horizontally in the longitudinal direction, this vibration caused an increase in the heat transfer of the heat pipe that was directly proportional to the input vibration energy below 500 mm2 Hz2. When the value of the vibration energy exceeded this value, the heat transfer enhancement per unit vibration energy decreased rapidly. Along with the decrease in the condensation section temperature, the average temperature of the heating section decreases. The influence of the condensation section temperature on the maximum heat transfer is much greater than that of the vibrations. [ABSTRACT FROM PUBLISHER]

Abstract: This study proposes an innovative building-integrated photovoltaic (BIPV) by integrating building structure, a heat flow mechanism, and a microencapsulated phase change material (MEPCM) with a photovoltaic (PV) module. Parametric simulations of the thermal and electrical performances of this PV module were performed to account for the influences of external and internal ambient environments, daily solar irradiation, and thickness as well as the melting point of the MEPCM layer. The results show that incorporating the appropriate microencapsulated phase change material layer can improve the thermal and electrical performances of the photovoltaic module. The melting temperature and aspect ratio significantly affect the thermal and electrical performance of the PV module. [Copyright &y& Elsevier]

Analysis of the spatial characteristics of disasters is a critical component of accurate disaster prevention planning and management. Reports from the Tainan City Fire Department were analysed to explore the spatial distribution of incident locations via address matching, spatial coordination transformation and GIS technologies. The characteristics of these locations were further investigated using spatial autocorrelation analysis in order to explore potential future demand for emergency rescue services. The performance levels of existing and newly added emergency rescue facilities were analysed using maximal covering location problem tests and Lagrangian heuristic calculations. These methods are able to simulate and analyse rescue performance after new facilities have been added to a system and the results can also be used to guide the future locations of rescue facilities. [ABSTRACT FROM AUTHOR]

Abstract: Double-skin roof is known as a very effective way to reduce both the conduction and convection heat transfers from roof to the ceiling of building, on the other hand, RBS (radiant barrier system) is very effective in blocking the radiation heat transfer between roof and ceiling. In this study, prototypical double roofs inspired by the concepts of both double-skin structure and RBS technique was specifically designed to cut down the solar heat gain from roof. The effect of energy saving was experimentally measured. A double roof structure, formed by a roof plate and an aluminum foil-PP (polypropylene) board-RC slab, can achieve good performance of heat barrier and is highly recommended. [Copyright &y& Elsevier]

Research on using phase change material (PCM) suspension to improve the heat transfer and energy storage capabilities of thermal systems is booming; however, there are limited studies on the application of PCM suspension in transient natural convection. In this paper, the implicit finite difference method was used to numerically investigate the transient and steady-state natural convection heat transfer in a square enclosure containing a PCM suspension. The following parameters were included in the simulation: aspect ratio of the physical model = 1, ratio of the buoyancies caused by temperature and concentration gradients = 1, Raleigh number ( R a T ) = 103–105, Stefan number (Ste) = 0.005–0.1, subcooling factor (Sb) = 0–1.0, and initial mass fraction (or concentration) of PCM particles ( c i ) = 0–0.1. The results showed that the use of a PCM suspension can effectively enhance heat transfer by natural convection. For example, when R a T = 103, Ste = 0.01, c i = 0.1, and Sb = 1, the steady-state natural convection heat transfer rate inside the square enclosure can be improved by 70% compared with that of pure water. With increasing Sb, the Nusselt number can change nonlinearly, resulting in a local optimal value. [ABSTRACT FROM AUTHOR]

The incorporation of phase change materials (PCM) in buildings has the potential to enhance the thermal efficiency of buildings, reduce energy cost, shift peak load, and eventually reduce air pollution and mitigate global warming. However, the initial capital cost of PCM is still high, and thus the establishment of a control strategy has become essential to optimize its use in buildings in an effort to lower investment costs. In this paper, an extensive review has been made with regard to various control strategies applied to PCM-enhanced buildings, such as ON/OFF control, conventional control methods (classical control, optimal, adaptive, and predictive control) and intelligent controls. The advantages and disadvantages of each control strategy are evaluated. The paper further discusses the opportunities and challenges associated with the design of PCM-enhanced buildings in combination with control strategies. [ABSTRACT FROM AUTHOR]

This study explores the effects of pipe wall properties (thermal conductivity k and wall thickness tw) on the heat transfer performance of a rectangular thermosyphon with a phase change material (PCM) suspension and a geometric configuration (aspect ratio = 1; dimensionless heating section length = 0.8; dimensionless relative elevation between the cooling and the heating sections = 2) that ensures the optimum heat transfer efficiency in the cooling section. The following parameter ranges are studied: the dimensionless loop wall thickness (0 to 0.5), wall-to-fluid thermal conductivity ratio (0.1 to 100), modified Rayleigh number (1010 to 1011), and volumetric fraction of PCM particles (0 to 10%). The results show that appropriate selection of k and tw can lead to improved heat transfer effectiveness in the cooling section of the PCM suspension-containing rectangular thermosyphon. [ABSTRACT FROM AUTHOR]

• Thermal resistance circuit model of forced convection in a concentric double tube is developed. • Numerical simulations have been performed to validate the thermal circuits developed. • The resulting local total thermal resistance fully demonstrated the local convective effect. • Applications of the convection thermal circuit derived have been demonstrated. Enhancing convection heat transfer performance of internal flows have been a subject of interest relevant to thermal engineering applications. The present study aims to elucidate, via a novel thermal circuit modeling, the heat flow paths and the heat transport mechanisms of thermally developing forced convection of concurrent fluid flows through the outer annulus and inner tube of an externally iso-flux heated concentric double tube, which was demonstrated as an effective heat transfer enhancement configuration with respect to its parent single tube under identical operation conditions, including the inlet fluid temperature, the total volumetric flow rate, the length of heated section, as well as the wall heat flux imposed. To examine the validity of the model developed, corresponding numerical simulations based on the finite volume method were conducted to evaluate the local thermal resistance relationships. The resulting local total thermal resistance fully demonstrated the local convective effect of the fluid flows in managing the heated wall temperature at the outer-ring wall, from which the local heated wall temperature can be readily evaluated from the given imposed heat flux and the inlet fluid temperature. [ABSTRACT FROM AUTHOR]

In this study, a numerical simulation of natural convection between two horizontal differentially heated pipelines inside a circular air-filled enclosure is performed using the finite difference method. The relevant parameters of the problem are the inclinations of the two cylinders (positioned vertically in this study, with the cold cylinder above the hot cylinder), the distance between cylinders and the Rayleigh number. The results show that transient irregular fluctuations in the flow field and heat transfer occur when the Rayleigh number increases or the distance between cylinders decreases. Under the current test conditions, increasing the Rayleigh number significantly increases the average heat transfer coefficient between the cold and hot cylinders. [ABSTRACT FROM AUTHOR]

This study explores the effect of different numbers of wall-mounted vent caps and their installation locations on the indoor air environment in residential kitchens, for which limited information is available. Wind tunnel tests were performed to study the induced ventilation rates of a vent cap, and the impact of vent caps on the natural ventilation efficiency in residential kitchens was examined using computational fluid dynamics (CFD) numerical simulations. The results were then applied to determine the appropriate quantity of vent caps and their proper installation location. The wind tunnel test results indicated that outdoor winds with speeds of 0–6 m/s that flow parallel to the wall with a vent cap induce indoor air to exit through the cap with ventilation rates of 0–20 m3/h; when the wind blows perpendicular to the wall, outdoor air with 0–31.9 m3/h flows indoors. CFD numerical simulations showed that the installation of kitchen vent caps can reduce the average carbon monoxide concentration in the cook's breathing zone. A sufficient quantity of vent caps and the proper installation location are required to ensure the natural ventilation effectiveness of wall-mounted vent caps. [ABSTRACT FROM AUTHOR]

This study combines microencapsulated phase change materials (mPCMs) (core material: paraffin; melting points: 37 and 43 °C) and aluminum honeycomb boards (8 mm core cell) to form mPCM roof modules and investigates their heat absorption and release performances, as well as their impact on indoor heat gain by conducting experiments over a 24-h period, subject to representative weather. The outdoor boundary conditions of the module are hourly sunlight and nighttime natural cooling; on the indoor side of the module, the conditions are daytime air conditioning and nighttime natural cooling. The results indicate that compared to a roof module with a 43 °C melting point mPCM, the roof module with a 37 °C melting point mPCM had improved peak load-shifting capacity, but had a slightly increased indoor heat gain. The mPCMs in both roof modules were successfully cooled during the night, returning to their initial state, to begin a new thermal cycle the next day. [ABSTRACT FROM AUTHOR]

This study combined building construction practice, aluminum honeycomb panels, and microencapsulated phase change material (mPCM) to construct an mPCM honeycomb wallboard. The daily thermal behaviors of this wallboard are investigated experimentally. The outdoor side of the wallboard is affected by daytime sunshine and nighttime natural convection, whereas the indoor side is subjected to forced convection or natural convective boundaries. The results show that indoor air conditions have a certain influence on the thermal performance of mPCM honeycomb wallboard and that the mPCM inside the wallboard can effectively dissipate heat when the indoor environment is subjected to either a forced or natural convection condition. Therefore, mPCM can always restore itself to its original thermal condition and is ready for heat management use the following day. [ABSTRACT FROM AUTHOR]

The incorporation of thermoelectric generators (TEGs) into building systems has considerable potential for energy harvesting and merits further exploration. In this study, the electricity generation and thermal characteristics of the TEG façades comprised of TEG cells and feasible wall constructions under different solar heating conditions (peak heat gain: 400–1200 W/m2) were experimentally investigated. The results showed that applying TEGs to a typical structural façade using a 25 cm-thick reinforced concrete (RC), the peak electricity generation was 100.0 mW/m2. For TEG nonstructural façades, if the indoor heat gain was considered, the TEG attached to the 2.5 cm-thick microencapsulated phase change material (mPCM) honeycomb board showed the highest energy ratio. Correlation equations of the power generated by TEG façades per unit area with time during the daytime are provided, which designers can use to estimate the power generation for a TEG façade with a given peak solar heat gain. [ABSTRACT FROM AUTHOR]

In this study, full-scale seismic testing and 3D finite element analysis were carried out on reduced web section (RWS) connections. A steel H-beam-to-box-column connection was designed to have two parallel long openings in the beam web. The opening was rectangular with semicircles at both ends. The design used the adjacent beam flanges to take shear forces with the beam web with openings, which made it possible to apply RWS connections with general sections. The design parameters were then selected to delay the occurrence of local plate buckling in the beam flanges near the beam web with openings, which ensured that the connections developed sufficient plastic deformation before reaching the maximum strength. The results showed that the refined design could move the plastic hinges of the connections away from the column faces. Moreover, after a complete loading cycle with a drift angle of 4% rad, the connections still had a moment strength of >80% of the beam plastic moment strength. The connection performance met the AISC seismic requirement. This design refinement makes it possible to further apply RWS connections to steel moment frames in building retrofits. • A novel steel connection is designed with two parallel horizontal openings on the beam web. • The openings are rectangular with semicircles at both ends. • Full-scale seismic testing and FEM analysis were carried out on the RWS connections. • The refined design could move the plastic hinges of the connections away from the column faces. • The connection performance met the AISC seismic requirement. [ABSTRACT FROM AUTHOR]

Abstract: In recent years, Radio Frequency Identification (RFID) has been considered an important technology affecting the development of industries around the world and is valued in many fields. In the construction industry, RFID benefits construction engineering and management by improving efficiency and control. This study describes the influence of combination manners of RFID and interior decorating materials on RFID system recognition by identifying appropriate combination manners and tag space layouts. The main study results include (1) building materials'' influence on effects of RFID, (2) readable distance between tags and readers, and (3) electronic wave penetration of passive tags. Limitations of the RFID applications on material management were also identified. [Copyright &y& Elsevier]

• A vertical dry storage cask for spent nuclear fuel is our target. • Ventilation patterns and heat dissipation were experimentally and numerically investigated. • Parameters include approaching wind angle (θ) and Reynolds number (Re). • Re = 8 × 104 is a critical condition for the channel airflow pattern in θ = 0° cases. • When θ = 45°, different wind velocities result in similar channel airflow patterns. In this study, wind tunnel experiments and computational fluid dynamics (CFD) simulations were conducted to observe the channel airflow patterns and heat dissipation characteristics of dry storage casks for spent nuclear fuel. The parameter ranges were as follows: model scale = 1/10, Grashof number (Gr) = 1.0 × 1011, approaching wind angle (θ) = 0° or 45°, and Reynolds number (Re) = 2.6 × 10 4 - 8.0 × 10 5. The results show that a wind velocity = 3 m/s (Re = 8 × 104) is a critical condition for the channel airflow pattern inside the cask for cases in which θ = 0°. When θ = 45°, different wind velocities result in similar channel airflow patterns. As the wind velocity increases, the overall average surface temperature of the canister decreases, and the decrease lessens as the wind velocity increases. [ABSTRACT FROM AUTHOR]

• Avertical dry storage cask for spent nuclear fuelis our target. • Heat removal and hybrid ventilation characteristicswerenumericallyinvestigated. • Buoyant airflow dominated heat removal at low Re (2.7 × 104). • When Re = 5.3 × 104–1.3 × 105, wind-induced airflow compromised the buoyant one. • When Re ≥2.7 × 105, wind-induced airflow dominated and heat removal increased. Computational fluid dynamics (CFD) was used in this study to numerically simulate the heat removal and hybrid ventilation characteristics of a vertical dry storage cask for spent nuclear fuel. The parameters included a Grashof number of 1.0x1011, an approaching wind incidence angle of 0° or 45°, and a Reynolds number (Re) of 2.7 × 10 4 - 8.0 × 10 5 (Gr / Re 2 = 0.15 - 1 37). As shown by the results, the buoyant airflow dominated the heat removal capability of the cask at low Re (2.7 × 10 4). When the Re was increased to 5.3 × 10 4 - 1.3 × 10 5 , the wind-induced channel airflow compromised the buoyant airflow, thus reducing the heat removal capacity of the cask. When the Re was ⩾ 2.7 × 10 5 , the wind-induced airflow dominated. [ABSTRACT FROM AUTHOR]

The use of renewable energy sources and carbon emissions has been debated from various perspectives throughout recent decades. However, the causal relationship between green energy sources and carbon emissions volatility has received limited attention. This study aims to close a knowledge gap in this area. The current study analyzes the renewable energy sources (wind, hydro, and geothermal) and carbon emissions of four ASEAN countries (Indonesia, Thailand, Vietnam, and the Philippines) between 2000 and 2019. The present study combined Chudik and Pesaran's (2015) newly developed Dynamic Common Correlated Effects (DCCE) with cutting-edge investigation tools such as first- and second-generation unit root tests; CS-dependence; Variance inflation factor test for multicollinearity; and Pedroni, Kao, and Wester Lund tests of co-integration. The Granger causality test is also used to check the short-term and long-term causal effects within the renewable energy sources and green energy sources, and carbon volatility. According to the empirical results, green energy sources make a positive and vital contribution to reducing carbon emissions growth in the above-noted ASEAN economies. Furthermore, short- and long-run causality runs from green energy sources to carbon emission volatility in the region. A significant causality relationship has also been observed within the green energy sources of ASEAN. [ABSTRACT FROM AUTHOR]

The impact of thermal comfort demand on the renovation process was carried out on an optimization basis for the thermo-modernization process of an exemplary single-family home located in Warsaw. The verified TRNSYS simulation program was used to generate a set of variants of building modernization solutions. This variants set was used afterwards as a database for optimization. The analysis performed includes the internal air temperature, indicators of thermal comfort (PPD), and annual energy demand for heating and cooling, and investment costs of modernization building. The results indicated the importance of analyzing various variants of building modernization solutions. Performing modernization without analyzing its effects can have positive as well as negative consequences, e.g., achieving a significant reduction in the primary energy demands at the expense of the deteriorated thermal comfort of users. It was shown that separate analysis of indicators leads to completely different solutions and should not be recommended during modernization of single-family buildings. [ABSTRACT FROM AUTHOR]

Heating, ventilating, and air-conditioning (HVAC) systems account for a large percentage of energy consumption in buildings. Implementation of efficient optimisation and control mechanisms has been identified as one crucial way to help reduce and shift HVAC systems' energy consumption to both save economic costs and foster improved integration with renewables. This has led to the development of various control techniques, some of which have produced promising results. However, very few of these control mechanisms have fully considered important factors such as electricity time of use (TOU) price information, occupant thermal comfort, computational complexity, and nonlinear HVAC dynamics to design a demand response schema. In this paper, a novel two-stage integrated approach for such is proposed and evaluated. A model predictive control (MPC)-based optimiser for supervisory setpoint control is integrated with a digital parameter-adaptive controller for use in a demand response/demand management environment. The optimiser is designed to shift the heating load (and hence electrical load) to off-peak periods by minimising a trade-off between thermal comfort and electricity costs, generating a setpoint trajectory for the inner loop HVAC tracking controller. The tracking controller provides HVAC model information to the outer loop for calibration purposes. By way of calibrated simulations, it was found that significant energy saving and cost reduction could be achieved in comparison to a traditional on/off or variable HVAC control system with a fixed setpoint temperature. [ABSTRACT FROM AUTHOR]

This review presents an analysis of three hypotheses. The articles provide a specific perspective on green housing before, during, and post COVID-19. The validations of these hypotheses were performed by analyzing the scientific literature worldwide and by adding a statistical analysis of appropriate articles from the Scopus database. The purpose of this review is to overview the research written on housing developments during the upsurge of COVID-19 along with the responses from the green building sector, because this field appears to be rapidly emerging by the sheer volume of research studies currently undertaken. Foremost peer-reviewed journals covering construction, urban studies, real estate, energy, civil engineering, buildings, indoor air, management, economics, business, environmental studies, and environmental sciences that were published last year were selected for review. The review was conducted by applying a combination of various keywords and the criteria for paper selection, including sustainable building, green construction, green building, resource-efficient, a building's lifecycle, COVID-19, energy, water, consumption, health effects, comfort, occupant behaviors, policy, economy, Industry 5.0, energy-efficient retrofitting, and profit. Two, innovative elements in this study stand out when comparing it with the most advanced research on green housing before, during, and after COVID-19. The first innovation relates to the integrated analyses of COVID-19 pandemic, housing policies of countries and cities pertinent to COVID-19 that impact green housing and the wellbeing of their residents as well as the impact made by residents and a housing policy on the dispersion of COVID-19. This research additionally establishes that a green building analysis is markedly more effective when the analysis comprehensively covers the life process of a green building, the participating interest groups that have their own goals they wish to implement, the COVID-19 situation, and the external micro- and macro-level environments as a singular entity. [ABSTRACT FROM AUTHOR]

Worldwide, buildings have been presented as one of the main energy consumers and, for that matter, there is an increased tendency to invest in policies and measures that promote more efficient buildings. Among the chosen strategies, the need to promote the use of passive solutions and retrofit the existing building stock is often pointed out. Portuguese building stock has proven to be obsolete in terms of thermal comfort, which can directly affect the energy demand for climatization purposes. Considering the great solar availability in the country, when compared to other European locations, building retrofit with solar passive technologies can be a suitable solution. This paper aims to review studies on the application of solar passive technologies to retrofit façades in the Mediterranean climate context, with a special focus on Portugal. Four retrofit passive solar technologies were reviewed, namely glazing, sun shading, sunspaces and Trombe wall technologies. [ABSTRACT FROM AUTHOR]

This paper analyses innovative activities, including renewable energy sources (RES) in the housing market, the motivations for their introduction, effectiveness, benefits, limitations and management—which are open and current problems of Polish and international sustainable construction. This problem is part of a research gap concerning, among others, the role of developers and entities responsible for introducing energy innovations into housing construction. The aim of the paper is to analyse innovations, with particular emphasis on RES, introduced by residential developers in Poland in the context of global trends. The work is based on the results of surveys conducted among developers of the primary housing market. The research of 130 questionnaires received from entities such as multi-storey buildings and multi-family houses in Poland, was carried out on a nationwide sample using the CATI Computer Assisted Telephone Interview method. The results of the survey research were summarized by setting research hypotheses, which were verified using the significance test based on the Laplace normal distribution. The research conducted has shown that residential developers in Poland point at, among others, competitive pressures, concern about the quality of products and services offered, increasing market share or satisfaction and increasing customer requirements. This clearly shows that the implementation of innovation is perceived through the prism of increasing competitiveness. Furthermore, developers operating in the more competitive markets—nationwide and on the market of the five largest Polish cities, usually larger companies, showed a greater willingness and even the need to introduce innovation in their activities. In the study, developers as one of the barriers of introducing innovations, apart from the lack of adequate support, mainly from public entities in the field of, inter alia, appropriate law favouring the implementation of innovations and financial support, indicate difficulties of the client's market manifested by the lack of knowledge and identification of needs in the field of innovation, and the lack of willingness to pay a higher price in regard to the product with higher innovation level. In the paper, the authors recommend developers, among others, to implement in the management process the identification of possible to implement innovations and the customers' needs in innovations with education in the field of possible innovations and its benefits. The article indicates the need to intensify the implementation of innovations in housing projects in order to increase competitiveness and to meet the European Union's requirement regarding the use of renewable energy sources. [ABSTRACT FROM AUTHOR]

The article assesses an impact of thermal retrofitting on an improvement of the energy quality of public buildings in terms of their heating. The analysis covered a group of 14 buildings, including schools, kindergartens or offices, while energy audits were carried out for 12 of them. The indications of individual gas meters were the source of actual data for the assessment of changes in energy consumption indexes in operating conditions. The analysis showed a clear improvement in the energy quality of buildings; however, the actual effects were much lower than forecasted. The average forecasted decrease in energy consumption was supposed to be 64.3%, but the measured data showed only 37.1%. The investigation confirmed that the most complex refurbishing provided the most satisfactory decrease in energy consumption (51.4% of real decrease in energy consumption), while objects with partial thermal refurbishing reached an efficiency of only 21.8%. It was stated that in operating conditions, special attention should be paid to the manner of energy use, since different indicators of energy consumption can be obtained with the same parameters of building's balance cover. The results obtained can be further utilized in thermal-refurbishment implementation procedures. Follow-up investigations on the impact of selected parameters on energy consumption are planned. [ABSTRACT FROM AUTHOR]

Optimal management of thermal energy storage in a building is essential to provide predictable energy flexibility to a smart grid. Active technologies such as Electric Thermal Storage (ETS) can assist in building heating load management and can complement the building's passive thermal storage capacity. The presented paper outlines a methodology that utilizes the concept of Building Energy Flexibility Index (BEFI) and shows that implementing Model Predictive Control (MPC) with dedicated thermal storage can provide predictable energy flexibility to the grid during critical times. When the utility notifies the customer 12 h before a Demand Response (DR) event, a BEFI up to 65 kW (100% reduction) can be achieved. A dynamic rate structure as the objective function is shown to be successful in reducing the peak demand, while a greater reduction in energy consumption in a 24-hour period is seen with a rate structure with a demand charge. Contingency reserve participation was also studied and strategies included reducing the zone temperature setpoint by 2 ∘ C for 3 h or using the stored thermal energy by discharging the device for 3 h. Favourable results were found for both options, where a BEFI of up to 47 kW (96%) is achieved. The proposed methodology for modeling and evaluation of control strategies is suitable for other similar convectively conditioned buildings equipped with active and passive storage. [ABSTRACT FROM AUTHOR]

To ensure broad application of renewable and energy-efficient energy systems in buildings and neighborhoods, profitable business models are vital. Energy supply contracting helps building residents to overcome the barrier of high upfront investment costs while additionally reducing risks related to energy-saving mechanisms. This study examines profitability for energy contractors in a variety of business cases that simultaneously ensure energy cost savings for the residents. A mixed-integer linear optimization model is developed for a neighborhood energy community, consisting of three buildings with diverse usages. In the process, the optimum capacities of building-attached and building-integrated photovoltaics, a heat pump and a gas-fired mini combined heat and power unit are determined to cover the energy community's electricity and heat load. Results show that cross-domain contracting within energy communities is highly profitable for both, the contractor and the residents, while the extent depends on the accounting method, assumed interest rate and depreciation time. The additional application of energy-efficiency measures in/on the buildings, constituting a combination of energy supply and energy performance contracting, further increases profitability. The investigation of several sensitivities shows that high grid energy costs for electricity and gas enhance profitability of local energy technologies, leading to an increase in optimal technology capacities. [ABSTRACT FROM AUTHOR]

Increasing the energy efficiency of residential and non-residential buildings is a crucial point towards the development of the sustainable cities of the future. To reach such a goal, the commonly employed intervention measures (for instance, on facades and glass) are not sufficient and efforts in reaching a fully renewable energy generation are mandatory. In this context, this paper discusses the applicability of a system with solar and biomass as the main energy sources in different climates for heating, cooling, domestic hot water and electricity generation in office buildings. The energy system includes solar thermal collectors with thermoelectric generators, a biomass boiler, a reversible heat pump/organic Rankine cycle and an adsorption chiller. The results showed that the system can operate with a share of renewables higher than 70% for all energy needs, with up to 80% of the overall energy demand supplied only by solar and biomass sources even in the northern locations. [ABSTRACT FROM AUTHOR]

• Conjugate heat transfer of PCM suspensions in a circular pipe was numerically investigated. • The circular pipe is confined to external cooling convection. • PCM concentration, bi o and ste affected the overall thermal performance. • Pe only had a significant effect on the axial heat transfer of the wall. In this paper, a numerical method was used to investigate the conjugate heat transfer of phase change material (PCM) suspensions in a circular pipe under external cooling convection. The parameters considered in this study and their ranges were the volumetric fraction of PCM particles (c v) = 0–0.2, the Biot number (Bi o) = 0.1–100, the Stefan number (Ste) = 0.01–0.2, and the Peclet number (Pe) = 100–1000. The results showed that the PCM concentration, Bi o , and Ste had significant effects on the fluid temperature, inner/outer wall temperature, and inner/outer wall heat flux, while Pe only had a significant effect on the axial heat transfer of the wall. When a PCM-containing working fluid was used for cooling, the PCM latent heat could directly affect the fluid outlet temperature and the cooling effect. If the latent heat is changed, other thermal system parameters should be adjusted accordingly. [ABSTRACT FROM AUTHOR]

• Cooling effects of a thermosyphon with PCM suspension were numerically and experimentally investigated. • Cooling effects are the subcooling at the cooling section and PCM supercooling. • The cooling effects affected the overall thermal performance. • Controlling the cooling wall temperature can achieve an appropriate subcooling effect. A numerical and experimental study is presented to explore the effects of cooling (the section on subcooling and phase-change material (PCM) supercooling) on the thermal performance of a rectangular thermosyphon containing PCM suspensions. In the numerical simulation, a continuum mixture flow model is used for the buoyancy-driven circulation flow of the PCM suspensions together with an approximate enthalpy model to detail the solid-liquid phase change process of the PCM particles in the loop. Parametric simulations are conducted in the following ranges: heat input at the heating section = 12 W, average temperature of the outer wall of the cooling section = 10–25 °C, and PCM mass concentration = 0–15%. The results show that in the configuration of this study, the downward flow of the high-density fluid in the cooling section became the main driving force of the circulation loop. Therefore, the cooling effects affected the overall thermal performance. To allow the proper melting/freezing of PCM particles, it is critical to control the wall temperature at the cooling section to achieve an appropriate subcooling effect. [ABSTRACT FROM AUTHOR]

We are investigating how to use urban design approaches to conduct the layout and basic design of newly-built high-rise buildings to reduce wind obstruction and create effective urban ventilation. Few studies have addressed this issue. This study analyzes the effects of high-rise building on pedestrian-level wind in downstream street canyons based on wind tunnel test results, and examines the suitability of an urban design specification. The height (H) of high-rise buildings and the airflow passage width (S) between adjacent high-rise buildings are key control factors for this issue; H/D = 3 and S/D = 1.125 are critical parameters and recommended values (D is the height of the downstream street blocks). [ABSTRACT FROM AUTHOR]

The pedestrian wind environment in a street canyon is affected by a multitude of factors, including the height and geometric shape of the surrounding buildings, the street width, the wind direction, and speed. Wind-tunnel tests were performed to determine the effects of constructing high buildings in an urban renewal project in New Taipei City, Taiwan on the pedestrian wind environments in the surrounding street canyons. The results show that replacing the original low-rise buildings with high-rise buildings could decrease the wind speed and natural ventilation potential in certain surrounding street canyons. The flow fields generated by approaching winds in various street canyons are highly complex in this practical case study. Thus, the pedestrian wind patterns in the street canyons cannot be interpreted in terms of channeling and shielding effects alone, as is typically reported in the literature. [ABSTRACT FROM AUTHOR]

The natural convection behaviors of rectangular thermosyphons with different aspect ratios were experimentally analyzed in this study. The experimental model consisted of a loop body, a heating section, a cooling section, and adiabatic sections. The heating and cooling sections were located in the vertical portions of the rectangular loop. The length of the vertical cooling section and the lengths of the upper and lower adiabatic sections were fixed at 300 mm and 200 mm, respectively. The inner diameter of the loop was fixed at 11 mm, and the cooling end temperature was 30 °C. The relevant parameters and their ranges were as follows: The aspect ratios were 6, 4.5, and 3.5 (with potential differences of 41, 27, and 18, respectively, between the cold and hot ends), and the input thermal power ranged from 30 to 60 W (with a heat flux of 600 to 3800 W/m2). The results show that it is feasible to obtain solar heat gain by installing a rectangular thermosyphon inside the metal curtain wall and that increasing the height of the opaque part of the metal curtain wall can increase the aspect ratio of the rectangular thermosyphon installed inside the wall and thus improve the heat transfer efficiency. [ABSTRACT FROM AUTHOR]

Using computational fluid dynamics (CFD), this study explores the effect of a different number of awning windows and their installation locations on the airflow patterns and air contaminant distributions in restrooms in K-12 (for kindergarten to 12th grade) public schools in Taiwan. A representative restroom configuration with dimensions of 10.65 m × 9.2 m × 3.2 m (height) was selected as the investigated object. Based on the façade design feasibility, seven possible awning window configurations were considered. The results indicate that an adequate number of windows and appropriate installation locations are required to ensure the natural ventilation effectiveness of awning windows. The recommended installation configuration is provided. [ABSTRACT FROM AUTHOR]