Performance of Near-Infrared Reflective Tile Roofs

2013 ◽  
Vol 770 ◽  
pp. 30-33 ◽  
Author(s):  
Thadsanee Thongkanluang ◽  
Jantharat Wutisatwongkul ◽  
Neramitr Chirakanphaisarn ◽  
Artorn Pokaipisit
Keyword(s):  
Near Infrared ◽  
Comparison Study ◽  
Cool Roof ◽  
Solar Reflectance ◽  
Green Pigments ◽  
Cool Roofs ◽  
Host Component

A green pigments based on a Cr2O3-Al2O3-V2O5-TiO2composition have been synthesized and the ability of these pigments used with ceramic glazes to confer high solar reflectance has also been studied. Cr2O3is the host component and the adding mixtures of Al2O3, V2O5and TiO2as the guest components. The composition denoted by T1 composes of Cr2O3, TiO2, Al2O3and V2O5are 80, 4, 14 and 2 wt%, respectively, gives near infrared solar reflectance of 82.8%. T1 green pigments were prepared for ceramic cool tile roofs (denoted by T1 cool roof). The comparison study on the effectiveness of T1 ceramic cool roofs and a commercial ceramic cool tile roofs (denoted by C cool roof) show that the T1 cool roof has given a better result by keeping the tested room about 4 °C cooler.

Design of a Cool Color Glaze for a Solar Reflective Tile

2014 ◽  
Vol 92 ◽  
pp. 159-167
Author(s):  
Chiara Ferrari ◽  
Alberto Muscio ◽  
Cristina Siligardi ◽  
Tiziano Manfredini
Keyword(s):  
Chemical Durability ◽  
Inorganic Pigments ◽  
Heat Island ◽  
High Chemical ◽  
Cool Roof ◽  
Island Effect ◽  
Solar Reflectance ◽  
Thermal Emissivity ◽  
Urban Heat ◽  
Cool Roofs

One of the most common materials-measures to counteract Urban Heat Island Effect can be identified in cool roof: white surface characterized by high solar reflectance and high thermal emissivity. One of the problems for the realization of cool roof is the difficult matching of white color with urban planning needs. In order to better integrate cool roofs into skylines cool colors were developed integrating pigments into cool roof surfaces. Cool roof market is actually dominated by organic based products with optimal solar performances but low durability against ageing. The use of ceramic-based products is crucial in the design of a new durable cool roof thanks to their naturally high thermal emissivity (ε=0.90) and their high chemical durability. The development of a new ceramic-based product made by a traditional porcelain stoneware tile as support, an inorganic engobe was started in the last years. In order to complete the product with a suitable glaze, eight different inorganic pigments were added to three different glazes, each one characterized by different surfaces features. Even if the addition of glazes, and pigments decrease the reflectance values of the solar reflective engobe, some promising results were achieved in this study especially regarding warm colored glazes.

Effect of roof and ceiling configuration on energy performance of a metamaterial-based cool roof for low-rise office building in China

2020 ◽  
pp. 1420326X2096155
Author(s):  
Saihong Tang ◽  
Nevzat Akkurt ◽  
Kai Zhang ◽  
Lufang Chen ◽  
Mingquan Ma
Keyword(s):  
Energy Consumption ◽  
Building Energy ◽  
Energy Performance ◽  
Office Building ◽  
Optimization Analysis ◽  
Cool Roof ◽  
The Past ◽  
Solar Reflectance ◽  
Electricity Saving ◽  
Cool Roofs

Cool roofs with higher solar reflectance and emittance can effectively reduce building energy consumption. However, it is still limited to use at night on account of the development of roof materials during the past decades. The newly proposed metamaterial-based cool roof (MCR) greatly improves the possibility of the radiative cooling in the daytime. To study the influence of MCR on the energy consumption for the office building, a small single-floor office was adopted to analyse the cooling performance of MCR by using EnergyPlus. In this study, the optimization analysis was conducted based on the proposed dimensionless thermal resistance ( θRTR) and roof pitch (Δ). Then the annual electricity saving potential of the office building with MCR was evaluated in details based on the selected cities from all five climate zones in China. The results show that more annual electricity saving can be achieved under the optimized values of θR7 = 1.53 and Δ = 20°. Furthermore, more than 15.7% of annual cooling electricity saving can be achieved while the optimized θRTR and Δ are applied.

Yellowish-Brown Pigment with High near Infrared Reflective

2014 ◽  
Vol 979 ◽  
pp. 102-106
Author(s):  
Thadsanee Thongkanluang ◽  
Jantharat Wutisatwongkul ◽  
Prayoon Surin
Keyword(s):  
Near Infrared ◽  
Colour Index ◽  
Brown Pigment ◽  
Inorganic Pigments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solar Reflectance ◽  
New Phase ◽  
Host Component

Yellowish-brown inorganic pigments having a high near infrared solar reflectance have been synthesized. In this research, Fe2O3 was used as the host component, whereas, the mixtures of Sb2O3, SiO2, Al2O3, and TiO2 were used as the guest components. The guest components were investigated over a range of 36 different compositions. The results showed that the pigment, denoted by YB32, with a composition of Fe2O3, Sb2O3, SiO2, Al2O3, and TiO2 of 65, 15, 10, 2 and 8 wt.% respectively, generated a maximum near infrared solar reflectance of 40.8% while the YB3 pigment was found to have a minimum reflectance of 29.3%. The CIE L*a*b* colour index was used to measure the yellowish-brown pigment colours. The YB32 and YB3 pigment powders were also characterized by powder X-ray diffraction technique. It was found that the YB3 powder developed a new phase, FeSb2O3, which is mainly responsible for the decrease in the near infrared solar reflectance.

scholarly journals Study on the Accelerated Aging Test Method in the Development of a Self-Cleaning Topcoat for Cool Roofs

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 605
Author(s):  
Taizo Aoyama ◽  
Takeshi Sonoda ◽  
Hideki Takebayashi
Keyword(s):  
Accelerated Aging ◽  
Test Method ◽  
Exposure Test ◽  
Cool Roof ◽  
Solar Reflectance ◽  
Astm Method ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
Self Cleaning ◽  
Cool Roofs

The heat island phenomenon in urban areas has become a problem in the recent years. One measure to overcome this, which has been attracting attention, is painting the cool roof with a paint that has high solar reflectance. However, the solar reflectance has been reported to decrease over time owing to staining from the paint. Our investigations reveal that a self-cleaning paint, based on an acrylic silicone polymer, is effective in maintaining a high solar reflectance and preventing dirt from adhering. These evaluations have been conducted on the cool roof of an actual building by conducting a pollution test under outdoor exposure conditions. In this study, we investigated an accelerated aging test and reported the results. ASTM D7897-15 (ASTM method) is an accelerated pollution test method for cool roofs, which has been established in the United States. In Japan, a similar accelerated pollution test method exists for antifouling civil engineering materials introduced by the Public Works Research Institute in Japan (PWRI method). The ASTM method and PWRI method were compared by conducting a stain acceleration test using a self-cleaning- and conventional-type cool-roof coating. The substitutability of the exposure test, correlation with the exposure test, performance evaluation of the paint, and the effect of the difference in the pretreatment conditions were verified. The results of these tests were reported.

scholarly journals Impact of Incorporating NIR Reflective Pigments in Finishing Coatings of ETICS

2021 ◽  
Vol 6 (6) ◽  
pp. 79
Author(s):  
Nuno M. M. Ramos ◽  
Joana Maia ◽  
Andrea R. Souza ◽  
Ricardo M. S. F. Almeida ◽  
Luís Silva
Keyword(s):  
Surface Layer ◽  
Surface Temperature ◽  
Near Infrared ◽  
Building Performance ◽  
Colour Difference ◽  
Colour Perception ◽  
Composite Systems ◽  
Solar Reflectance ◽  
Building Cooling ◽  
The Impact

Near-infrared (NIR) reflective materials are being developed for mitigating building cooling needs. Their use contributes to broadening the range of colours, responding to the urban aesthetic demand without compromising the building performance. Despite the increase in NIR reflective pigments investigation, there is still a knowledge gap in their applicability, impact, and durability in multilayer finishing coatings of External Thermal Insulation Composite Systems (ETICS). Hence, the main goal of this work consists of evaluating the impact of incorporating NIR reflective pigments (NRP) in the solar reflectance of the surface layer of ETICS, without affecting the colour perception, as well as their influence on the colour durability and surface temperature. As such, colour, solar reflectance, and surface temperature were monitored for 2 years in dark-coloured specimens of ETICS, with and without NRP and a primer layer. It was confirmed that the main contribution of NRP is the increase of solar reflectance and, consequently, the decrease in surface temperature, especially for high exterior temperatures (around 30 ºC). Moreover, these pigments highly increase the NIR reflectance without affecting the visible colour. In addition, they contribute to maintaining the colour characteristics. The application of primer increased the surface temperature, especially for higher exterior temperatures. However, it contributes to a lower colour difference and solar reflectance variation, which is an important achievement for durability purposes.

Thermal performance assessment of cool roofs on supermarkets through case analysis in 13 cities

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juan Carlos Ríos-Fernández
Keyword(s):  
Energy Consumption ◽  
Air Conditioning ◽  
Energy Savings ◽  
Real Data ◽  
Research Approach ◽  
Environmental Implications ◽  
Content Type ◽  
Cool Roof ◽  
Increase Energy Efficiency ◽  
Cool Roofs

PurposeThis paper aims to study the use of cool roof technology to avoid unnecessary energy consumption in supermarkets. This will allow to reduce and even cancel the heat absorbed by the roofs, transferring it to the buildings and thus, creating more sustainable cities.Design/methodology/approachThirteen real supermarkets with cool roofs were analysed in Australia, Canada, the USA and Spain. An analysis of so many supermarkets located in different parts of the world with different climatic zones has allowed an inductive analysis, obtaining real data of energy consumption associated with the air conditioning installations for a year with and without implementing the cool roof technology.FindingsThe paper provides insights on how the use of cool roof managed to reduce the need for energy for heating, ventilating and air conditioning by between 3.5 and 38%. Additionally, this technology reduces the annual generation of carbon dioxide (CO2) emissions per square meter of supermarket up to 2.7 kgCO2/m2. It could be an economical technology to apply in new and old buildings with a period of average economic recovery of four years.Research limitations/implicationsBecause of the chosen research approach, the research results may be generalisable. Therefore, researchers are encouraged to test proposals in construction with other uses.Practical implicationsThe paper includes economic and environmental implications for the development of cool roof technology and smooths the way for its implementation to increase energy efficiency in commercial buildings.Originality/valueThis paper is an innovative contribution to the application of cool roof technology as a source of energy savings in commercial construction through the analysis of supermarkets located in different countries with different climate zones. This will help other researchers to advance in this field and facilitate the implementation of the technology.

scholarly journals Cool Roof Impact on Building Energy Need: The Role of Thermal Insulation with Varying Climate Conditions

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3354 ◽  
Author(s):  
Piselli ◽  
Pisello ◽  
Saffari ◽  
Gracia ◽  
Cotana ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Thermal Energy ◽  
Building Energy ◽  
Energy Performance ◽  
Cold Climate ◽  
Climate Conditions ◽  
Building Energy Performance ◽  
Cool Roof ◽  
Solar Reflectance

Cool roof effectiveness in improving building thermal-energy performance is affected by different variables. In particular, roof insulation level and climate conditions are key parameters influencing cool roofs benefits and whole building energy performance. This work aims at assessing the role of cool roof in the optimum roof configuration, i.e., combination of solar reflectance capability and thermal insulation level, in terms of building energy performance in different climate conditions worldwide. To this aim, coupled dynamic thermal-energy simulation and optimization analysis is carried out. In detail, multi-dimensional optimization of combined building roof thermal insulation and solar reflectance is developed to minimize building annual energy consumption for heating–cooling. Results highlight how a high reflectance roof minimizes annual energy need for a small standard office building in the majority of considered climates. Moreover, building energy performance is more sensitive to roof solar reflectance than thermal insulation level, except for the coldest conditions. Therefore, for the selected building, the optimum roof typology presents high solar reflectance capability (0.8) and no/low insulation level (0.00–0.03 m), except for extremely hot or cold climate zones. Accordingly, this research shows how the classic approach of super-insulated buildings should be reframed for the office case toward truly environmentally friendly buildings.

Thermal and energy performance of green roof and cool roof: A comparison study in Shanghai area

2020 ◽  
Vol 267 ◽  
pp. 122205 ◽  
Author(s):  
Yang He ◽  
Hang Yu ◽  
Akihito Ozaki ◽  
Nannan Dong
Keyword(s):  
Green Roof ◽  
Energy Performance ◽  
Comparison Study ◽  
Cool Roof
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