Reflective Glazing Research Articles

Identifying Façade Orientations with Closely Similar Thermal Performance for Unifying Façade Design Features in Hot Arid Climate

Large-scale residential projects require architects to balance energy efficiency, thermal comfort, and cost-effectiveness in designing building units distributed in different orientations. Applying a single design to all orientations may not result in comfort conditions and energy efficiency; meanwhile, creating a unique design solution for each orientation can be time-consuming and costly to implement. Despite numerous studies recommending design alternatives for particular orientations, the ranges where orientation changes do not demand a change in the façade design still need to be determined. This research aims to identify ranges for which changes in building orientation do not necessitate changes in the façade design. It involves conducting parametric energy and thermal comfort simulations in a test room and testing the findings using real-life datasets from a large-scale residential project. Glass type, window-to-wall ratio (WWR), and utilization of shading devices were among the design parameters investigated. Results show that for all-year-round occupancy projects, a common solution can be applied for orientation changes between 0° to 10° from the north, −10° from the south, and ±5° from east and west for WWR of less than 50% in hot arid climates. These ranges can increase for small WWRs and when reflective glazing or shading devices are applied. This helps streamline design and construction processes, lower costs, and save energy in large-scale residential projects.

Energy, comfort, and environmental assessment of passive techniques integrated into low-energy residential buildings in semi-arid climate

Residential buildings consume a lot of energy, particularly after the recent pandemic and remote working lifestyle. Thus, it is crucial to design energy-efficient buildings that reduce energy consumption without losing indoor thermal comfort. In this regard, integrating affordable passive strategies can improve thermal comfort, energy efficiency, and other environmental setbacks. In this study, several passive techniques were parametrically analyzed and tested in real semi-arid conditions using building simulation tools. The analyzed passive strategies include a phase change material (PCM), reflective paint, insulation, double-clear glazing, double low-E glazing, reflective glazing, and shading. Three of Monterrey’s major energy-consuming typical houses were analyzed, and the optimum configuration was selected based on annual energy saving and initial material cost-effectiveness. Although the PCM was thermally effective when integrated into walls and roofs, as well as in terms of total energy reduction, the results showed that it was not cost effective. Therefore, insulation and reflective paint in walls and roofs were applied in conjunction with low-E glazing and shading in all cases to save more than 50% of energy annually. The use of these energy-saving techniques increased the hours of comfort by up to 45%, resulting in a reduction of up to 3000 kgCO2e.

Integrating Daylighting with Task-Ambient Lighting for Enhanced Energy Savings in Office Spaces

Daylighting has been widely studied as a fundamental aspect of spatial illumination and energy efficient façade design. Effective installation and control of shading devices diminishes the adverse effects of prevailing climatic conditions on building envelope performance and reduces resultant lighting and cooling energy consumption. Task-ambient lighting as a free-standing approach has also been proven to reduce lighting energy consumption compared with typical general ambient lighting. This study estimates the energy saving potential of integrating daylighting through fixed external horizontal shading slats with task lighting. Spot measurements were taken in a test room to validate a daylight calculation program. Full year indoor work plane daylight simulations were performed for office spaces of different floor areas and varying window to wall ratios. Indoor daylight quality was assessed using the Useful Daylight Illuminance metric and three different task lighting schemes explored. Lighting energy savings of 10% to 90% were estimated under the three schemes in comparison to similar office spaces with common unshaded heat reflective glazing.

Conventional and Advanced Glazing Technologies for Enhancing Thermal and Lighting Performance

Glass is one of the oldest man-made material that is widely used in architecture. As it is a translucent material, it permits a full penetration of direct sunlight but may also increase the internal space temperature and then increasing cooling loads and energy consumption. As the need for energy optimization is very important and glazing is considered a weak point in any building, the selection of glazing assumes tremendous significance. This paper reviews the different types of glazing which can be categorized into conventional and advanced to optimize the thermal and the lighting performance according to their properties and insulation values. Conventional glazing includes the clear glazing whether it is single double or triple, the tinted glazing, the reflective glazing, and the low-E glazing. Advanced glazing which is mainly the insulated glazing unit such as the gas filled glazing, the vacuum glazing, the aerogel glazing and the phase change material glazing.

Identification of Automotive Cabin Design Parameters to Increase Electric Vehicles Range, Coupling CFD-Thermal Analyses with Design for Six Sigma Approach

<div class="section abstract"><div class="htmlview paragraph">The ongoing global demand for greater energy efficiency plays an essential role in vehicle development, especially in the case of electric vehicles (EVs). The thermal management of the full vehicle is becoming increasingly important, since the Heating, Ventilation, and Air Conditioning (HVAC) system has a significant impact on the EV range. Therefore the EV design requires new guidelines for thermal management optimization.</div><div class="htmlview paragraph">In this paper, an advanced method is proposed to identify the most influential cabin design factors which affect the cabin thermal behavior during a cool down drive cycle in hot environmental conditions. These parameters could be optimized to reduce the energy consumption and to increase the robustness of the vehicle thermal response.</div><div class="htmlview paragraph">The structured Taguchi’s <i>Design for Six Sigma</i> (DFSS) approach was coupled with CFD-Thermal FE simulations, thanks to increased availability of HPC. The first control factors selected were related to the thermal capacity of the panel duct, dashboard, interior door panels and seats. Surface IR emissivity and solar radiation absorptivity of these components were then added to the study. Car glass with absorptive and reflective glazing were finally included in the study. The design space of 18 vehicle configurations was simulated in spring and hot summer conditions, with steady state thermal simulations. A 2-step optimization was then conducted, trying first to increase the robustness of the cabin response and, secondly, to reduce the equivalent temperature actually felt by passengers. The <i>Verify</i> phase was then conducted on the <i>Best Engineering</i> design emerged by the 2-step optimization, through quasi-transient CFD-Thermal FE analyses. The thermal results were then sent to a CFD 1D energy prediction model, confirming the HV battery energy saving and the extended range reached during the cool down drive cycle.</div></div>

BRIGHTNESS PERFORMANCE OF OFFICE INTERIOR DUE TO ROOM’S WINDOW COMPONENTS CONFIGURATION

The paper reports room’s brightness performance of glass dominance office building facade in Jakarta due to the use of tinted and reflective type of glass wall and the combination of these with internal roller and venetian shading types. Method used to collect the data was mainly by direct measurements at three open-plan office buildings with different window components configurations under overcast sky condition, and at parallel sitting positions. Comparing the results of measurement with the standard of luminance value for office building was used as data analysis. Results show that the window components configuration influenced the luminance values of the interior and thus affected mostly on the brightness perception of the rooms. Both tinted and reflective glazing configured with roller blinds yielded accepted luminance value of rooms’ surfaces. They contributed to bright enough light perception of the rooms. On the other hand, the problem of room’s luminance values may occur with the use of reflective type of glass configured with the venetian blinds. The blinds exacerbated the daylight coming from window in which it resulted in significantly high average luminance value of the window.

An Analysis of Indoor Air Temperature and Relative Humidity in Office Room with Various External Shading Devices in Malaysia

External shading devices have been utilized very extensively in office buildings in the tropics to reduce the amount of solar radiation entering into the buildings. In addition, the shading systems significantly improved the performance of day lighting by controlling the amount of lights levels of illumination entering into buildings. During hottest days, the impact was higher; however, the shading layers could still increase the amount of temperature gains through the glazing. Several methods can be employed to improve indoor thermal environment including using light colors for external surfaces, using a reflective glazing system, and using the appropriate thermal properties of external structure and roof. Therefore, this paper discusses the indoor temperature and relative humidity by using indoor temperature and relative humidity equipment (HOBO Data Logger) for office room with three different types of shading devices in Malaysia, which are focusing on the vertical shading, horizontal shading and egg-crate shading. The objectives of this research are; to measure the indoor air temperature and relative humidity in the office building, to identify the highest, lowest and average indoor temperature and relative humidity in the office building, to compare with standard guideline of air temperature and relative humidity and to find out which shading is suitable to be applied in achieving thermal comfort in an office The method use in this research is field measurement. The results indicate that egg crate shading has asignificant impact on decreasing indoor temperature as well as discomfort hours compared with other shading types.

Water-Filled Double Reflective Window And Its Year-Round Performance

Window glazing is a weak element in building construction from the aspect of thermal insulation. To save building energy by using advanced glazing system is efficient and important. A novel design of water-filled double reflective glazing system is here introduced and the prediction of its annual performance through computer simulation with the use of Hong Kong TMY weather data is presented. The monthly indoor heat gains through the window are compared with conventional single/double reflective glazing. The results show that the indoor room heat gain can be largely reduced by utilizing this novel glazing system. Besides, the absorbed heat by water flow in cavity can be used as a pre-heated water source to serve the hot water system. So there is a great energy-saving potential in its application in large buildings.

The Potential of Shading Devices for Temperature Reduction in High-Rise Residential Buildings in the Tropics

The present study focuses on the effect of shading devices on the indoor temperature of high-rise residential buildings in the hot–humid climate of Malaysia. Several methods can be employed to improve indoor thermal environment, including using a reflective glazing system, using light colors for external surfaces, and using the appropriate thermal properties of external walls and roofs. However, before using any of these methods, it is important to have an optimum shading device to reduce the solar radiation absorption that leads to an overheated indoor environment and an increase in cooling energy loads. Therefore, the main objective of the current paper is to find the extent of a building's solar heat gain and, consequently, the indoor air temperature that is influenced by the external shading devices. A computerized simulation tool (IES<VE>) is used to carry out the investigation, taking Penang as the empirical background of the hot–humid climate. The results indicate that egg-crate shading has a significant impact on decreasing discomfort hours compared with other shading types.

Investigation on energy performance of double skin façade in Hong Kong

Double skin façade can be defined as a building façade covering one or several stories with multiple skins. The skins may be air tight or ventilated. With sophisticated study and design, buildings constructed with double skin façade can have better thermal performance than the conventional single skin façade. This paper reports the findings on the energy performance of double skin façade applied to a typical office building under the climatic condition in Hong Kong. An experimental setup was established and the measured data were used to verify the theoretical model developed via the EnergyPlus simulation program. The validated model was then used to evaluate the energy performance of double skin façade with various configurations including glazing type (clear, absorptive or reflective glass), glazing position (inner or outer pane) and glazing layers (single or double glazing material). The results indicate that a double skin façade system with single clear glazing as the inner pane and double reflective glazing as the outer pane can provide an annual saving of around 26% in building cooling energy, as compared to a conventional single skin façade with single absorptive glazing. However, the long payback period of 81 years makes the double skin façade system economically infeasible. Support and motivation are needed from the local government in order to foster successful and widespread application of the double skin façade system in buildings.

Double versus single skin facades in hot arid areas

Double skin facades are defined as two layers of facade separated by an air gap, that varies in its depth creating a solar chimney effect where warm air rises by buoyancy. As a facade technology, its thermal and daylight performance is still under scientific scrutiny. The bulk of research on the performance of this facade configuration is carried out in moderate climates. However, little is understood about the performance of double skin facade configurations in extreme hot arid climates. This investigation adopts an analytical approach using a dynamic simulation software (IESVE), to convert general intuitions on the performance of a double skin facade, in hot arid areas, into the grounds of understanding its performance based on research. It is an opportunity to study this facade configuration before the technology is transferred into construction in hot arid areas. In this paper, a comparative analysis of cooling loads on a single skin base case is compared against three possible changes to the physical properties of the external layer of the double skin facade. A dynamic thermal performance software APACHE-Sim is used (integrated environmental solutions IESVE, version 5.1). Simulation results indicate that a reflective double skin facade can achieve better energy savings than a single skin with reflective glazing.

Energy performance of windows in high-rise residential buildings in Hong Kong

At the present time in Hong Kong in its hot and humid climate, a single pane, clear glazing is most often used in windows of tall residential buildings. During this study, we employed HTB2, detailed building heat transfer simulation software, to evaluate a decrease in the yearly cooling load ( Q) and in the peak cooling-load ( D) in two residential flats due to different glazing single pane types and different flat orientations. The investigated glazing types were clear glazing, tinted glazing, reflective glazing, and tinted and reflective glazing.

Reflective glazing and its effect on the environment around buildings

Reflective glazing and its effect on the environment around buildings