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This paper investigated the artificial neural network (ANN) modeling to forecast the one-hour ahead global and diffuse solar radiation using the observed data during 2019-2021 at a meteorological station in Bangkok, Thailand. Results from the statistical analysis portrayed the abundance of the tropical solar radiation and its large variation all year round. As a step to move advance the renewable energy use of the solar radiation at the location, the ANN forecasting models were proposed for all climatic conditions. The model input were the ambient temperature, solar elevation, and an insolation parameter namely normalized global solar radiation. The model performance was assessed by using the two statistic parameters: normalized mean bias error (nMBE), and normalized root mean square error (nRMSE). The results showed that the ANN models could forecast the global radiation with the nMBE of 1.79% and nRMSE of 26.20%. For the diffuse radiation forecast, the nMBE and nRMSE of the models were obtained at 7.78% and 36.21%, respectively. In order to demonstrate a benefit of the two developed ANN models, their forecasted horizontal data were employed to further predict the total solar radiation on vertical plane. Benchmarked with the smart persistence model, the developed ANN models possessed the higher forecasting accuracy for all weather conditions. [ABSTRACT FROM AUTHOR]

Urban settlements are home to the greatest levels of greenhouse gas emissions and energy consumption globally, with unprecedented rates of urban expansion occurring today. With the majority of global urbanization occurring along the periphery of urban areas in developing countries, investigation of 'green' building practices designed specifically for 'peri-urban' regions is critical for a low-emitting future society. This study assesses a state-of-the-art residence designed for a middle-class family of four residing in the peri-urban region of Bangkok, Thailand. The residence employs both demand-side management strategies and low-emitting energy supply technology to achieve energy-positive status. To elucidate the influence that key design decisions have on the life cycle sustainability of the home, several variants of the residence are modeled. A process-based life cycle assessment consistent with the International Organization for Standardization (ISO) 14044:2006 standard and following ReCiPe Midpoint life cycle impact assessment methodology is used to quantify the life cycle impacts per square meter of conditioned residence floor area for climate change (582 kilograms [kg] carbon dioxide equivalent), terrestrial acidification (4.01 kg sulfur dioxide equivalent), freshwater eutrophication (30.4 grams phosphorous equivalent), fossil depletion (362 kg iron equivalent), and metal depletion (186 kg oil equivalent) impacts. We model multiple scenarios in which varying proportions of Bangkok's peri-urban detached housing demand are fulfilled by the energy-positive residence variants. Under the best-case replacement scenario (i.e., 100% replacement of future peri-urban detached housing), significant reductions are achieved across the life cycle climate change (80%), terrestrial acidification (82%), and fossil depletion (81%) impact categories for the steel-framed, energy-positive residence. [ABSTRACT FROM AUTHOR]

Nanofilms of a polymer mixer of two ionomers, poly 3,4-ethylenedioxythiophene:poly(styrene sulfonic acid) (PEDOT:PSS), were used as conducting materials to develop transparent conducting electrodes. It was firstly found that convective deposition, a versatile and wide-area coating method, could be used for the coating and acid treatment of PEDOT:PSS films. Electrical conductivity of the PEDOT:PSS films was significantly enhanced up to 1814 S/cm by only one-time surface treatment by a mild acid solution (4 M methanesulfonic acid). This is because some PSS chains were removed out from the polymer mixer films without damage on the substrates. UV-vis-NIR spectroscopy, Raman spectroscopy, and cyclic voltammetry were used to characterize the acid-treated transparent conducting films. In this report, obtained transparent conducting PEDOT:PSS films on polyester substrates were used as flexible electrodes for fabrication of flexible electrochromic devices. Poly(3-hexylthiophene) (P3HT) was used as an active layer, which its color changed reversibly from transparent-light blue to purple with a small applied voltage (±3 V). [ABSTRACT FROM AUTHOR]

An automated blind can provide energy saving and better comfort. To obtain these benefits a computer program that is able to calculate interior illuminance, heat gain, glare discomfort and thermal comfort has been developed. The thermal performance of the window system was investigated. From the study it is found that installing a venetian blind in between the double-pane glass window causes a significant reduction in heat gain compared to the plain glass window. The heat gain through the window system in the shortwave part of the radiation is analyzed. The slat reflectance, slat angle and solar profile angle are the major affect on the shortwave part of solar heat gain coefficient. The blind using a lower value of slat reflectance has a lower shortwave part of solar heat gain coefficient. The effective solar heat gain coefficient (SHGC) and the effective overall heat transfer coefficient (U) for the double-pane glassed window with enclosed horizontal slats was developed. These SHGC and U value can be used with the equation to calculate the Overall Thermal Transfer Value (OTTV) of Thailand's building energy code to evaluate a building that use the double-pane glassed window with enclosed venetian blind. [ABSTRACT FROM AUTHOR]

Abstract: In the tropics, daylighting from a side window requires shading to intercept direct sunlight from the window whilst allowing penetration of daylight from sky. In this paper, daylighting from a double-pane glazed window with enclosed horizontal slats (slat window) was investigated for which it is situated on either north or south wall of a room. Full-scale experiments and simulations were conducted to characterize distribution of the interior daylight from the slat window under a real tropical climate. Performance of the slat window was evaluated in terms of the “useful daylight illuminance” (UDI), interior daylight availability and light power density (LPD) of an integrated dimmable lighting system. Empirical formulas were developed for determining annual average LPD values of the dimmable lighting system over its served area. The LPD value can be used with a reduced form of the energy equation of Thailand's building energy code to evaluate the reduced annual electrical energy consumption for accreditation of the daylight use in a building. The analysis of life cycle cost proved that the daylighting from the slat window integrated with the dimmable lighting system is cost effective. [Copyright &y& Elsevier]

The International Commission on Illumination has adopted a set of fifteen standard sky luminance distributions (SSLD). One of our previous papers uses a least squares method to sort sky luminance measurements from a station located north of Bangkok into fifteen slots, each corresponding to each type of SSLD, to appraise the statistics of occurrence of each sky type at the location. The paper also uses Kittler's method (Kittler; and others, 1997) to prepare paired values from the measurements sorted and obtains parameter values of the gradation function and those of the indicatrix function separately from measurements in each slot. This paper applies evolutionary computation to obtain a set of parameter values for both gradation function and indcatrix function simultaneously under least squares criterion. This method enables all measurements in each slot to be used. The resulting luminance distribution function thus obtained for each sky type possesses lower bias error and lower mean square error than those of the corresponding type of SSLD when both are evaluated against measurements [ABSTRACT FROM AUTHOR]

The tropical sky is highly luminous. This gives rise to expectation of its high potential for daylighting. The availability of an accurate luminance distribution for daylight from the sky would help advance the movement for daylighting. On the other hand, accurate radiance distribution model is also needed to help manage the undesirable heat gain due to solar radiation penetration in airconditioned buildings. Towards these ends, eight luminance and radiance distribution models were evaluated against luminance and radiance measurements recorded in a station located north of Bangkok. Due to prevalence of intermediate and cloudy sky conditions in the tropical region, attention was paid to seeking models that could perform well under these conditions. It turns out that a number of models are acceptable, but no single model performs distinctively well for the prevalent conditions. [ABSTRACT FROM AUTHOR]

Sky luminance and illuminance measurements from the daylight measurement station at the Asian Institute of Technology, Pathumthani, Thailand show that there is usable daylight throughout office hours on every day of the year. The variability of daylight, however, poses a challenge when attempting to characterize the sky and to develop models of daylight availability. Calculation of interior daylight and heat gain, and integration of electric lighting with daylighting are also a challenge. The disadvantages of glare and heat gain can overwhelm the benefits of daylighting in air-conditioned buildings if care is not taken. These problems are associated with clear and intermediate skies, and the combined frequency of occurrence of these conditions is 60%. [ABSTRACT FROM AUTHOR]

Abstract: Vernacular residential houses in Thailand were not heated nor cooled. The walls of such houses were constructed from wood and other light natural materials. Air-conditioning to cool interior spaces is now common and brick and concrete has replaced natural materials for walling. Even when a house is designed for air-conditioning, no insulation is used on the enclosing walls. It is generally believed that thick and heavy walls reduces cooling load in a space but insulation may not and is too costly. This paper presents results from an experimental and simulation study on comparative thermal performance of walls enclosing spaces that are used to serve three residential functions of bedroom, living room, and studio room. The study considers different levels of insulation and its placement at the interior and exterior surfaces on walls with and without windows, and for each functional use of a space. Use of external shading and blinds or curtain is not considered in this study. In all cases, the study concludes that insulation placed at interior wall surface improves wall thermal performance and is superior to that of exterior placement. The latter part appears to contrast with what have been found in similar studies taken under cool climate. [Copyright &y& Elsevier]