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Purpose: On the one hand, one of the most important global strategies to improve thermal comfort in urban spaces is using cool materials (high albedo materials) in urban facades. On the other hand, using cool materials in urban facades is a big challenge. Over time, the albedo of cool materials that modified by titanium dioxide (TiO2)-based photocatalytic self-cleaning materials (PSTiO2) does not decrease. In fact, its self-cleaning property prevents the loss of the initial albedo of the material. The self-cleaning performance of these materials was investigated in previous researches. However, their thermal performance in urban space has not been investigated yet. This paper studied the performance of these materials on the urban square facade. Design/methodology/approach: The thermal performance of PSTiO2 on the thermal comfort of the urban square was evaluated by ENVI-met(v4). The results simulated by ENVI-met software with field measurements in the urban Square were compared. Field measurements of air temperature were conducted on 22 July and 30 March. Findings: The results showed that these materials, despite their self-cleaning properties, have significant thermal impact in the urban environment. Using plaster modified by PSTiO2 (albedo 0.6) improved slightly by nearly 0.2 °C the thermal comfort of the urban square. Whereas, white paint modified by PSTiO2 (albedo 0.9) reduced the physiologically equivalent temperature (PET) by 0.5 °C, because reflection of solar radiation increased between the buildings facades. The simulation results showed that due to the space is more enclosed in the square entrance, the mean radiant temperature (Tmrt) increased. As a result, PET index rose too. Originality/value: This study shows that employing cool and self-cleaning materials in the urban facades of Jolfa Square, in addition to have self-cleaning property, is effective in the amount of thermal comfort of the square. In the parts of the square where the enclosure is less, an improvement in thermal comfort was observed. The performance of the cool and self-cleaning materials in the facade in terms of thermal comfort is completely dependent on the physical parameters of the urban space.

• The cooling effect of SCFs is studied using reduced-scale field experiments. • The cooling effect of the SCFs weakens with the increase in the floor height. • Applying SCFs to the west and south windows results in lower indoor temperature. • Using SCFs and cool materials can reduce the indoor air temperature by up to 4.5 ℃. • Cool materials can weaken the insulation effect of SCFs at night. Solar control films (SCFs) have been widely studied as energy-saving retrofitting for buildings. To investigate the cooling effect of SCFs, a series of reduced-scale outdoor experiments were conducted to analyse the cooling effects of different kinds and orientations of SCFs and the joint effect of SCFs and cool materials. The impact of various weather conditions and nighttime use of SCFs on indoor air temperature was also discussed. It was found that the unidirectional fluoroscopy grey film (UFF-G) had the best cooling effect, reducing indoor air temperature by up to 4 ℃. The maximum temperature difference in indoor air caused by SCFs on different orientations can reach 4.8 °C, with west or south-facing SCFs resulting in lower indoor temperatures. Additionally, using both SCFs and cool materials can result in a maximum temperature decrease of 4.5 °C compared to using SCF alone. The cooling effect of SCFs could decrease on overcast and rainy days, and buildings without SCFs have lower indoor air temperatures at night. Our experimental results can offer theoretical references for energy-saving renovation of glazing systems with SCFs, creating a more comfortable indoor thermal environment and energy-efficient buildings. [ABSTRACT FROM AUTHOR]

In areas with high levels of solar radiation, decreasing the amount of solar energy absorbed by the building envelope is useful to reduce the need of air conditioning and "heat island" effects. Most high-reflective products, however, suffer from low durability. The COOL-IT project is developing an innovative high-reflective cement based mortar for precast products to be used as outer layer in buildings for both vertical and horizontal surfaces, or for road pavement. The mix design is aimed at increasing the durability of this cement-based component while retaining high reflectance to solar radiation. This paper presents the preliminary results of the project, based on the simulation of the energy demand of a residential building, intended as a support to optimize the proposed mixes. The model is analysed in three different locations in Italy, for one year of operation. This allows evaluating the trade-off of the energy demand between the winter increase and the summer reduction.

In this study, photoluminescent glass tiles with different content of yellow-emitting pigments are tested as a promising adaptive strategy for investigating their potential for lighting energy saving and passive cooling in the built environment. The capability of such materials to re-emit light after a certain solicitation period has indeed gained increasing attention as an innovative solution to reduce building energy consumption and mitigate the urban heat island phenomenon. Following this line, photoluminescence is here studied through spectrophotometric and spectroradiometric measurements, during both its charging and decay phase. Analytic corrections are then applied for the first time to isolate only the photoluminescent effect from the overall experimental data. Results demonstrate how higher contents of photoluminescent pigments do not always correspond to the best performance: tiles with an intermediate concentration provide for the longest afterglow decay time (up to 79 min) and the highest reduction in solar energy absorption (up to 26.8 W/m2). • Yellow-emitting glass tiles are studied for urban passive cooling applications. • In-lab spectrophotometric and spectroradiometric tests are carried out. • Original analytical procedure allows to isolate the luminescence on samples' behavior. • Reflectance and luminance increase with the percentage of pigments in the sample. • The highest concentration of pigments does not provide the best light efficiency. [ABSTRACT FROM AUTHOR]

Four building arrays, each comprising 25 building models, were utilized to investigate the effects of cool materials on building surface temperatures, indoor temperatures, and street microclimates in Guangzhou, China. The experiments are divided into three groups. The first group of the experimental models is used to investigate the cooling effect of the roof using cool materials on the roof surface and indoor environment. The results show that using cool materials on roofs can significantly reduce roof surface and indoor temperatures of the top floor by 13.5 °C and 3.9 °C at noon under an average global solar radiation (GSR) of 727 W/m2. The second group of experiments included four arrays: one control group without cool materials and three other arrays applying cool materials on the third, second, and first floors, respectively. Using cool materials on the façades of the third, second, and first floors reduced the indoor temperature by an average of 1.9 °C, 0.8 °C, and 0.5 °C (average GSR = 404 W/m2), respectively. As a result, higher floors receive more solar radiation, and cool materials show better cooling capacity. The third group is used to investigate the effect on street air temperatures when cool materials are used on all building façades. Overall, the effect of cool materials on the street air temperature is very small, with a maximum reduction of only 0.2 °C in the street air temperature. [Display omitted] • Four building arrays consisting of 100 building models were used. • The cooling effect of cool materials on indoor, building surface, and street air were analyzed. • Using cool materials on high-floor façades has a better cooling effect than on low-floor ones. • Cool materials on the top floor reduce indoor temperatures by 1.4 °C more than the first floor. • The effect of cool materials on the street air temperature is minimal, less than 0.2 °C. [ABSTRACT FROM AUTHOR]

In areas with high levels of solar radiation, decreasing the amount of solar energy absorbed by the building envelope is useful to reduce the need of air conditioning and "heat island" effects. Most high-reflective products, however, suffer from low durability. The COOL-IT project is developing an innovative high-reflective cement based mortar for precast products to be used as outer layer in buildings for both vertical and horizontal surfaces, or for road pavement. The mix design is aimed at increasing the durability of this cement-based component while retaining high reflectance to solar radiation. This paper presents the preliminary results of the project, based on the simulation of the energy demand of a residential building, intended as a support to optimize the proposed mixes. The model is analysed in three different locations in Italy, for one year of operation. This allows evaluating the trade-off of the energy demand between the winter increase and the summer reduction. [ABSTRACT FROM AUTHOR]

The need to tackle the urban heat island effect demands the implementation of cool surfaces as a mitigation strategy. This study comprehensively reviews the evolution of this research field from a materials perspective. It provides a bibliometric analysis of the relevant literature using the SciMAT software processing of bibliographic records from 1995 to 2020, for the evolution of cool surfaces. The results obtained show an increased interest in the field from 2011 to 2020, particularly for roof applications, and present the scientific evolution of reflective materials. According to the materials dimension adopted by the development of the research field, the study is refined from a bibliometric analysis of 982 selected records for the analysis of five themes: (i) Pigments; (ii) Phase change materials; (iii) Retroreflective materials; (iv) Ceramic materials; and (v) Glass. These materials present promising results in terms of their solar reflectance performances in the mitigation of the urban heat island phenomenon. At the end of this review, recommendations for future studies are provided for the creation of economic and environmentally friendly materials based on waste glass recycling. This study represents a valuable contribution that provides a scientific background with regard to cool surfaces from a materials perspective for future investigations. [ABSTRACT FROM AUTHOR]

Multi-colored pigments based on rare earth (RE) with the formula of LiRE(MoO 4+δ) 2 (RE = Ce, Pr, Nd, Er) were developed via the solid-state reaction method. Related characterization techniques were used for investigating the crystal structure, morphology characteristic, reflecting property, and color performance of the synthesized pigment. The prepared pigment of LiRE(MoO 4+δ) 2 (RE = Ce, Pr, Nd, Er) shows four colors, namely orange-yellow (Ce), bright green (Pr), lavender (Nd) and pink (Er). Moreover, all of the pigments possess high NIR reflectance in the range of 95–98% at 1100 nm. Remarkably, the average NIR reflectance of LiCe(MoO 4+δ) 2 pigment reaches up to 95.28%, and the NIR solar reflectance is also up to 95.02%. Besides, the pigment of LiCe(MoO 4+δ) 2 exhibits good yellow hue (b* = 75.08). The application practical of LiCe(MoO 4+δ) 2 coated on galvanized sheet exhibits excellent coloring performance. The designed pigments show chemical stabilities in the acid/alkali testing. All of above, the superior performances of color and reflectance from LiRE(MoO 4+δ) 2 provide visual enjoyment for people and exhibit potential for energy savings. [ABSTRACT FROM AUTHOR]

Phosphorescence (PP) has emerged as a promising passive cooling solution for the built environment, characterized by its ability to emit radiation persistently after photon absorption, thereby enhancing the solar radiation rejection capability and effective albedo of the surface. While various compounds have shown excellent properties for energy-saving purposes, assessing their benefits for the built environment towards their actual implementation still remains a challenge. To bridge the gap between laboratory-scale characterizations and real-world applications, this study employs the Princeton Urban Canopy Model (PUCM) to assess the surface cooling potential of PP coatings. This research represents the first numerical modeling of phosphorescence, extrapolating findings from experimentally validated parameters to conditions and scale of real cities. Results demonstrate the substantial capacity of PP to ameliorate surface overheating in urban areas, potentially reducing surface temperatures by up to −2.6 °C when optimized. Additionally, material optimization emerges as a crucial factor for exploiting the potential of phosphorescence in mitigating urban overheating, highlighting its strategic relevance for the urban canopy environment. • A novel mathematical model for phosphorescence is developed. • Photoluminescence is implemented in an urban canopy model for the first time. • Various emission colors are evaluated to find the best UHI mitigation option. • The potential of an optimized photoluminescent material is assessed. • Benchmarking against traditional solutions is performed for several canyon geometries. [ABSTRACT FROM AUTHOR]

The need to tackle the urban heat island effect demands the implementation of cool surfaces as a mitigation strategy. This study comprehensively reviews the evolution of this research field from a materials perspective. It provides a bibliometric analysis of the relevant literature using the SciMAT software processing of bibliographic records from 1995 to 2020, for the evolution of cool surfaces. The results obtained show an increased interest in the field from 2011 to 2020, particularly for roof applications, and present the scientific evolution of reflective materials. According to the materials dimension adopted by the development of the research field, the study is refined from a bibliometric analysis of 982 selected records for the analysis of five themes: (i) Pigments; (ii) Phase change materials; (iii) Retroreflective materials; (iv) Ceramic materials; and (v) Glass. These materials present promising results in terms of their solar reflectance performances in the mitigation of the urban heat island phenomenon. At the end of this review, recommendations for future studies are provided for the creation of economic and environmentally friendly materials based on waste glass recycling. This study represents a valuable contribution that provides a scientific background with regard to cool surfaces from a materials perspective for future investigations.

Cool materials, with their high reflectivity, can significantly reduce the heat absorbed by buildings in summer and thus reduce energy consumption. The amount of solar radiation received by building surfaces varies with their orientation, so the effectiveness of cool materials on different building surfaces may vary. This study investigated the effects of using cool materials on scaled-down building models and full-scale real buildings through a combination of experiments and simulations, considering factors including building surfaces of different orientations, material properties, and weather conditions. Both experimental measurements and simulation studies showed that applying cool materials on roofs has the best cooling effect, reducing indoor temperatures by 0.93 °C in full-scale models. The south and west façades also showed good cooling effects when using cool materials. The north façade has the least cooling effect when using cool materials. Compared to exposed cement boards and regular materials, cool materials showed significantly better cooling effects, similar to those of 2 cm thick XPS insulation boards. Overall, buildings with poorer thermal insulation performance benefit more from the cooling effect of cool materials in summer. Additionally, the cooling effect of cool materials is ineffective on cloudy and rainy days. We found that the cooling effect of cool materials was significantly reduced when the solar radiation was less than 400 W/m2. The findings of this study provide guidance for the use of cool materials in energy retrofitting of existing buildings and the construction of low-carbon cities. • The combined experimental and simulation approach was employed. • The thermal insulation properties of four building surface materials were compared. • The cooling effect of using cool materials on different oriented building surfaces was analyzed. • Using cool materials on roofs can lower indoor temperatures by 0.93 °C for real buildings. • The effect of cool materials is significantly reduced when solar radiation is less than 400 W/m2. [ABSTRACT FROM AUTHOR]

Polymer-ceramic hybridization is an important method for preparing functional materials. Strontium titanate (SrTiO 3 , ST), a typical perovskite ceramic, has been widely applied in the electronics industry and photocatalytic fields. However, ST was barely reported to be utilized in cool materials. Herein, ST ceramic, as a solar reflective pigment, was introduced into a polymer matrix to prepare cool material. Specifically, the influences of both weight contents and surface grafting modification about ST on the properties of poly(methyl methacrylate) (PMMA)/ST composites were investigated, which include cooling performance, surface roughness, thermal emissivity, dispersion of particles and mechanical strength. The obtained composites containing 20 wt% unmodified ST possess excellent cooling property due to high thermal emissivity (86.8%, in 8–13 μm) and high solar reflectance (70.7%, in the whole solar band) which increased by 142% than that of pure PMMA resin. Temperature test highlighted that the composites containing 20 wt% unmodified ST was only 26.6 °C, 11.4 °C lower than that of PMMA resin and only 2 °C higher than initial temperature. Moreover, the surface grafting modification of ST by the silane coupling agent was proved to improve the dispersibility of ST in PMMA resin. Both the cooling and mechanical properties of composites containing modified ST particles were further improved. Though the solar reflectance of PMMA/ST composites was lower than that of PMMA/TiO 2 composites, temperature tests showed that the PMMA/ST composites had a similar cooling performance with the PMMA/TiO 2 composites when the content of the ceramic particles were 5.8 v%. This work not only prepared the polymer-ceramic hybrid materials with excellent cooling performance but also expanded the application of ST ceramic in the field of composites. [ABSTRACT FROM AUTHOR]

Human subject experiments were conducted to investigate the influences of thermal load and thermal sensation under various outdoor radiation environments. The experiments were conducted at locations simulating the application of ground surface materials with different solar reflectance, tall trees, green walls, hedges, and retro-reflective materials. The results revealed that a quantitative evaluation of the heat transfer between the human body and the surrounding environment using the human thermal load may be connected to the thermal sensation felt under various radiation environments. The improved effects of the thermal sensation by the decrease in reflected solar radiation from the ground, the decrease in transmitted solar radiation from the sky, the decrease in infrared radiation from the wall surface, the decrease in reflected solar radiation toward the human body from a window surface, and the shielding of infrared radiation from the ground surface were quantitatively evaluated based on the human thermal load. [ABSTRACT FROM AUTHOR]

• The effect of cool and super cool materials on urban ventilation was investigated. • The cooling effect of these materials on building surface temperature was analyzed. • The highest reduction in roof temperature is 13.4 °C for super cool materials. • The cool and super cool materials have no cooling effect at 16:00 in winter. • The cool materials have less than 6% impact on neighborhood ventilation. The application of cool materials in cities inevitably has an impact on the urban microclimate, but there is a lack of such studies. Therefore, this study investigated the effects of cool and super cool materials on building surface temperature, pedestrian-level pollutants, and neighborhood ventilation capacity using the CFD simulation method based on six typical residential neighborhoods in Nanjing, China. The results show that the cooling effect of the cool and super cool material on the building surface of slab morphology is greater than that of the building surface of point morphology at noon due to the buildings of slab morphology having a larger area of the south façade to reflect more solar radiation. The highest reduction in roof temperature is 10.7 °C and 13.4 °C for cool and super cool materials in summer. In addition, residential neighborhood with slab-parallel arrangement has the highest pedestrian-level pollutant concentrations regardless of building surface material. The effect of cool and super cool materials on the residential neighborhood's microclimate is small, less than 6% in summer and winter. In short, cool materials have a greater impact on the heat gain of buildings and can contribute to building energy efficiency in summer. [ABSTRACT FROM AUTHOR]

The importance of studying tropical urban climate was recognised by the World Meteorological Organisation (WMO) as early as in 1981 but substantial improvements were seen only in the last two decades. However specific knowledge of tropical urban climate still lags behind that of temperate climate. In this paper, authors review the state of the art in tropical heat island intensity, its influence on building energy consumption and the effect of urban compactness in the tropics. The review is limited to peer-reviewed journal publications found on four databases: Web of Science, Scopus, Google Scholar and Science Direct. The review indicates that although the tropical belt has large variations in topography, forest cover, land mass and development patterns, much of the current work is confined largely to Far East Asia, South Asia and South America. Future studies should focus on protocol for parameterisation and standardisation of measurement, in depth and scientific understanding of the influence of vegetation, water and topography, survey and monitoring of the context specific relationship between UHI and energy consumption, development of database for numerical model validation and improvement, and the context specific development of LCZ based institutional framework to integrate UHI mitigation strategies with environmental design guidelines. [ABSTRACT FROM AUTHOR]

Urban heat island is an anthropogenic phenomenon affecting urban outdoor thermal comfort conditions and energy utilization. This is even truer in urban canyon configurations, characterized by low sky view factor and where the effect of short-wave and long-wave solar radiation on construction surfaces is able to produce massive outdoor local overheating. Traditional solutions cannot always be applied in urban historical canyons, where the exteriors of buildings cannot be modified due to preservation. Here, the capability of innovative cool materials to mitigate local microclimate of historical urban canyons is investigated. A preliminary experimental characterization of the materials is performed. A numerical simulation of the microclimate effect generated by the application of such materials is performed. Results show that the proposed materials improve the microclimate without neglecting preservation constrains. Such materials set the best scenarios in terms of thermal comfort, by enhancing albedo on canyon surfaces. Their application on the vertical surfaces of narrow canyons can lead to deleterious effects on outdoor thermal comfort. Such findings are confirmed by PMV and MOCI analyses. Energy efficiency solutions may be effectively implemented in historical districts, opening the doors to other tailored solutions, such as integrated renewables, to make these environments more sustainable and comfortable. [ABSTRACT FROM AUTHOR]

For the field of cool material, barium titanate (BaTiO 3 , BT) is still a new member that needs to be further studied. Herein, the effects of both content and surface hydrophobic modification of BT on the cooling properties of acrylonitrile-styrene-acrylate copolymer (ASA) were detailedly investigated, aiming to fabricate composited cool material. Butyl acrylate (BA) was employed to convert the surface of BT from hydrophilic to hydrophobic. The addition of unmodified BT could significantly improve the solar reflectance of ASA, especially when the addition amount is 3 vol%, the near infrared (NIR) reflectance increased from 22.02 to 72.60%. However, serious agglomeration occurred when the addition amount increased to 5 vol% and therefore led to a relatively smaller increase in solar reflectance and an obvious decline in impact strength. After surface hydrophobic modification, the modified BT (M-BT) presented better dispersibility in ASA matrix, which contributed to the improvement of both solar reflectance and impact strength. In addition, the temperature test provided a more sufficient and intuitive way to evaluate the cooling effect of the composited cool materials, and a significant decrease (over 10 °C) could be achieved in the temperature test when M-BT particles were introduced. [ABSTRACT FROM AUTHOR]

As global warming accelerates at an alarming rate, there has been growing interest in passive radiative cooling solutions that can spontaneously cool objects without requiring energy consumption. This study investigates the emission performances of combined phosphorescent (P) and fluorescent (F) pigments for use as radiative cooling materials. Previous research has shown the potential of photoluminescence in reducing urban surface temperatures by reflecting and emitting incident solar radiation. P and F pigments were combined in different ratios to achieve a balance between brightness and persistency. The results indicatethat P pigments have higher luminance values but decay more rapidly, while specific ratios of P and F pigments provide reasonable luminance and longer afterglow. This study identifies the optimal "fluorescence-phosphorescence" combination for possible implementation of FP pigments in more complex materials for the built environment. These findings contribute to the development of effective radiative cooling solutions that can mitigate the impacts of global warming. [Display omitted] • The emission of mixed fluorescent (F) and phosphorescent (P) powders is studied. • Energy transfer processes occur from P to F pigments, resulting in longer emissions. • Increasing FP content and emission tuning possibility is studied on polymeric films. • Controlled combinations of P and F materials achieve energy savings in the city • Higher FP contents in polymeric films translate into higher luminescent intensities. [ABSTRACT FROM AUTHOR]

Nowadays, the undesirable heat generated from solar energy troubles people a lot in various aspects, including the energy consumption for cooling purposes, the potential safety hazards of the outdoor devices used in high-temperature environment and so on. Therefore, many cool materials emerge as the times require, which can mitigate these serious situation. In this study, a concept of solar reflective ASA (acrylonitrile-styrene-acrylate terpolymer) for cool material was proposed. To achieve this purpose, several inorganic particles with high solar reflectance were chosen to mix with ASA via melt blending to improve the cooling property of ASA. Ultraviolet-visible-near infrared (UV-Vis-NIR) spectral and temperature test were carried out to evaluate the cooling properties of ASA and its hybrid composites. The results of the solar spectral test showed that the addition of only 1% volume fraction of inorganic particles could effectively improve the solar reflectance of ASA. And ASA/barium titanate (BaTiO 3 ) hybrid composite possessed the highest reflectance value of 67.66%, nearly 2 times that of neat ASA. The results of the indoor temperature test were in highly consistent with those of the solar reflectance, which showed that all the hybrid composites presented better cooling effect compared with neat ASA. Also, ASA/BaTiO 3 hybrid composite exhibited the best cooling effect, nearly 10 °C lower than neat ASA. Besides, the outdoor temperature test showed the same trend with the indoor temperature test. Furthermore, the results of the mechanic test indicated that the improvement of the cooling properties was based on no sacrifice of the mechanical properties. [ABSTRACT FROM AUTHOR]

The need to improve energy efficiency of existing buildings is more than understandable and compelling. It is expressed through the EU Directive 2002/91/EU concerning the energy performance of buildings, the Greek Law 3661/08 concerning the improvement of the energy performance of buildings; which constitutes the harmonization of the Directive in the Greek legislation as well as the Regulation on Energy Efficiency Buildings (KENAK) which together with the Technical Instructions of the Technical Chamber of Greece, are the main application of the Legislation. The composite cool materials are a new and interesting solution for the constructions. Having identified -with extensive bibliographic research- the existing state of the market for thermal insulation materials and trends, these composite materials were characterized as a successful option. Finally, external thermal insulation composite systems were produced (with photocatalytic coating) and composite materials for the roof (extruded polystyrene with low reflectivity ceramic tile) which were analyzed -initially theoretically- in order to determine the energy performance of the building before and after their application, and then applied to an existing building. Additionally, there were determined the conditions before and after the installation of materials for thermal insulation capacity, by measuring the rate of heat transfer, by conducting measurements for the evaluation of the implementation of the new products of thermal comfort and air quality as well as by representative measurements of the microclimate of the area both during summer and winter. The results of the energy performance of new materials after their first application are to be presented [ABSTRACT FROM AUTHOR]

Marble envelopes represent a relatively common architectural solution used in variety of historic, modern and contemporary building facades. White marble envelopes have been shown to reduce solar heat gains, while improving indoor thermal comfort and energy efficiency in summer time. While marble is useful in this context, the urban atmosphere accelerates the degradation of marble elements. This leads to changes in optical characteristics, hence the aesthetics, and affects the energy efficiency benefits offered by white marble facades. These issues are investigated in order to predict the impact of degradation on energy performance and to the aesthetic value, such as change of color and luminosity. In this study, surface degradation of white marble is analyzed by means of accelerated weathering in the laboratory while examining changes to the optical characteristics of the materials. A dynamic simulation is carried out to assess the energy performance of a building as a case study. [ABSTRACT FROM AUTHOR]

A novel pyrophosphate BaCr2(P2O7)2 was synthesized by the conventional solid-state reaction. The X-ray diffraction (XRD), FTIR spectrum, scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) near infrared (NIR) reflectance spectra were applied to characterize the powders. The refractive indexes and nature of the VB and CB were determined. The structure, color properties and application were investigated. The results reveal that the anomalist bodies with smooth surfaces were obtained at 1200 °C with a mean size of 3 µm. A high reflectance peak at 535 nm was observed in the visible region, which is associated with the brilliant and deep green color of this pigment. With all the acids, alkali and deionized water treatment, the polycrystalline pigment BaCr2(P2O7)2 was found to be durable in chemical stability. The significantly high NIR solar reflectance of BaCr2(P2O7)2 is 90.0%, a higher cooling ability, so it has been selected to be tested as cool green pigment in ceramics. Moreover, this novel pyrophosphate pigment has great potential as cool pigment for surface coating applications. [ABSTRACT FROM AUTHOR]

The role of urban surfaces in climate is recognized worldwide. Cool pavements such as reflective and water-retaining pavements contribute to the mitigation of urban heat. To optimize the cooling performance of a combination of reflective and evaporative characteristics, water-retaining (WR) pavements, with reflectance values of 13% (WR13) and 25% (WR25), were used and compared to a conventional asphalt pavement (AS). In addition to measuring surface and atmospheric temperatures, human-energy balance known as "human-thermal load" was assessed using perceptive responses obtained from participants (n = 78). Experimental insolation conditions were classified as low-, medium-, and high-based on radiation effects. Water-retaining pavements demonstrated significant surface temperature reductions compared to the overall AS; however, air temperature and humidity above the pavement were less sensitive, and they were not significantly different between the two distinct pavements. Under high insolation, local thermal comfort improved and skin temperatures of the lower body reduced. These consequently reduced the temperature perceived in the whole-body and improved the thermal environment on the surface of WR13. These results can be reasonably explained using the human-thermal load. The increase in thermal load from reflected solar radiation is limited below a certain level of insolation. The overall radiation received by WR13 was moderate from both ground-reflected and -sourced infrared radiation sources. The human-thermal load of WR13 was significantly different from that of AS under high insolation. A modest reflective pavement, such as WR13, is anticipated to improve human thermal comfort. • Water-retaining and asphalt pavements are evaluated for human-thermal environments. • Methodology for the evaluation of human-thermal comfort on pavements is proposed. • Human comfort on pavements is determined by the extents of radiation components. • Water-retaining pavement with a lower reflectance is beneficial for heat mitigation. [ABSTRACT FROM AUTHOR]

Novel, photoluminescent and translucent construction elements are considered for application on buildings' envelope toward energy savings and avant-garde architectural expression. These elements allow natural light to pass through the envelope and charge the materials, which on their turn re-emit energy as visible light. By exploiting the intrinsic characteristics of these construction elements large amounts of energy could be saved in lighting applications. This work tackles the complex, dynamic behavior of photoluminescent materials by means of a novel, experimental and numerical methodology. Materials' dynamic characteristics are firstly investigated by means of an in-lab experimental campaign. Secondly, coupled lighting and energy numerical simulations are carried out. Results show that translucent and photoluminescent envelope components could be able to reduce up to 40% building electricity consumption for lighting on an annual basis and depending on urban surroundings. In the best-case scenario, i.e. during the longest day of the year, the obtained electricity savings are around 80% for the photoluminescent–translucent envelope. • Photoluminescent–translucent tiles are studied for buildings' envelope. • In-lab spectrophotometric and spectroradiometric analyses are carried out. • Potential real-scale integration is verified via dynamic energy and lighting simulations. • Illuminance requirements are met considering both daylighting and photoluminescence. [ABSTRACT FROM AUTHOR]