Effects of Future Climate Change and Adaptation Measures on Summer Comfort of Modern Homes across the Regions of the UK

The global climate is warming rapidly, with increasing frequency of severe events including heatwaves. Building insulation standards are improving to reduce emissions, but this can also lead to more overheating. Historically, UK house designers have not included adaptation measures to limit this. Most studies of the problem have had limited geographical or future climate scope. This study considers the comfort performance of a small modern house, in detached, semi-detached, and terrace (row) forms, but otherwise identical. Overheating is evaluated according to established criteria, including night-time bedroom hours over 26 °C. Simulations are carried out using median future weather years for current, 2030s, 2050s, and 2080s climates under medium- and high-emission scenarios for 14 regions of the UK. The results show a very large increase in overheating by the 2080s in all regions. With solar shading and natural ventilation, overheating is reduced considerably, maintaining comfort in most northern regions in the 2050s and a few northern regions in the 2080s. Differences between medium and high emissions are generally less than between different decades. Terraced (row) houses consistently overheat slightly more than semi-detached, with detached showing the least overheating.

Comparative field tests of an electrochromic shading device - thermal and visual comfort

Electrochromic devices (EC), or Smart Windows, are amongst the most promising technologies to increase users’ wellbeing in buildings. A comparative test of EC windows performance was realised in the ZEB Test Cell Laboratory in Trondheim, Norway. Two identical rooms were used for the comparative tests. One of the rooms was equipped with EC devices. The other room was equipped with a traditional insulated glazing unit (IGU) with external solar shading device. Three automatic control strategies were tested in this experiment. The EC device demonstrated a good impact on the thermal and visual comfort when compared to a traditional IGU without moveable shading and a traditional IGU with an external screen.

The impact of using Closed Cavity Façades (CCF) on buildings’ thermal and visual performance

Glazing is a critical buildings element as it is the most vulnerable envelope part to heat gain and heat loss accounting for around 50% of a building’s energy consumption. However, conventional glazing technologies have relatively low-performance characteristics which cause significant heat losses during winter and undesired heat gain in summer. In this regard, this study investigates the thermal and visual performance of various design configurations of a novel glazing technology, named Closed Cavity Façade (CCF), in comparison with traditional glazing technologies. Several CCF configurations were examined using Energy Plus and IDA ICE and compared to the baseline Double Glazing Unit (DGU) (traditional or thermochromic). MATELab, an office-like test facility at the University of Cambridge was used as the model for the simulations, which was beforehand experimentally validated. The results showed extensive benefits of CCFs compared to DGU systems, in terms of thermal performance and comfort. A 22-41% or 21-37% decrease in annual total energy consumption, compared to traditional DGU or thermochromic respectively, are identified along with a positive effect on thermal comfort with a significant reduction in radiant discomfort. Further investigation showed that glass coatings and solar shading device’s characteristics play an important role in achieving further performance improvements.

Method of assessing the reduction of solar heat on window surface shaded by continuous vertically slanted shading devices

The research discusses calibration of the method used to calculate solar heat transfer through shaded windows with continuous vertical slanted shading devices (below is abbreviated as "vertical slanted fins") with any slant angle Θ through a radiation reduction coefficient - Kbt. In order to evaluate the reduction of solar heat on window surface shaded by shading devices, a designated coefficient β of solar heat gain reduction through glazed windows should be established. It is the ratio of the transmitted amount of solar heat (including direct and diffuse radiation) through windows with shading device QK to those without solar shading device QKo. The study also introduces two in-house software programs. These programs help calculating solar heat gain and coefficient β for vertically slanted fins with any slant angle θ for 16 window orientations. The results of this study will be applied to the implementation of the Vietnamese national code QCVN 09:2017/BXD towards energy efficiency in buildings.

Efficiency of Solar Shading Devices to Improve Thermal Comfort in a Sports Hall

Thermal environment in sports facilities is probably one of the most important parameters, determining the safety and performance of athletes. Such facilities, due to the required operating temperature and physical activity of users, are a serious challenge for both investors and administrators, especially in summer. The additional criterion of low energy consumption in extremely airtight and well-insulated passive buildings often results in overheating of the interior, creating considerable economic and operational problems. The significant need to reduce solar gain during periods of high outdoor temperatures for low-energy buildings prompts a variety of design solutions. Sun shading systems, as an indispensable element of glazed surfaces, are designed to control the amount of solar radiation reaching the building interior, at the same time creating a favorable microclimate inside. This article analyzes the effects of sun shading, which have actually been applied and modified on the southern façade of a passive sports hall in Słomniki. Measurements of the thermal conditions in the hall were the starting point, on the basis of which a model of the object was created in the DesignBuilder program. Using simulation analyses, thermal conditions arising with the use of different variants of internal and external shading devices were studied in the program. The results presented in the article show that in a well-insulated hall of large volume, appropriately selected external shading devices are only able to reduce the access of sunlight to the rooms. External brise-soleils are able to limit the access of solar radiation to the rooms by up to 30%, but this is not enough to guarantee internal thermal comfort. Internal blinds do not affect the interior microclimate significantly and do not protect protection from overheating. Momentary differences in PMV values for different patterns of closing the blinds do not exceed 0.2.

Determining the optimum fixed solar-shading device for minimizing the energy consumption of a side-lit office building in a hot climate

Buildings consume nearly 40% of the annual global energy consumption, with about 70% in hot climate regions. An efficient building design in every aspect is a crucial step towards minimizing such consumption. Windows system, including solar shading attachment, plays a pivotal role in designing a sustainable building. At the beginning, a survey of architectural firms was conducted to assess the current local practice of selecting the type and size of solar shading devices in different orientations. Regrettably, the survey outcomes did not consolidate the designers’ basis for choosing such solar shading devices. Therefore, the main aim of this study is to find the optimum solar shading type and size among the three most common types (simple overhang, louvers, and overhang/sided-fins) in each façade orientation (East, West, North, and South). The manipulated design parameters comprised the overhang projection from the wall base to half of the window’s height and sided-fins projection (from the wall base to half of the window’s width), as well as the overhang projection’s tilt angle (from 90° to 135°). The considered design parameters provide 4416 design options that were handled efficiently by using the simulation-based optimization technique (SBOT). The results showed that the overhang/sided-fins performed best in terms of reducing the total energy consumption in all orientations (13-28%), while louvers’ shading came second on all orientations by saving 10–21% except in the East, where the simple overhang showed slightly better performance by saving 22%. Recommended type and size for the solar shading in each orientation have been provided.

A Solution-processed Inorganic Emitter with High Spectral Effectiveness for Efficient Daytime Radiative Cooling in Hot Humid Climates

Daytime radiative cooling provides an eco-friendly solution to space cooling with zero energy consumption. Despite significant advances, most state-of-the-art radiative coolers show broadband infrared emission with low spectral effectiveness, which limits their cooling temperatures and climate applicabilities, especially in hot humid regions. Here we report an all-inorganic narrowband cooler comprising a solution-derived SiOxNy layer sandwiched between a reflective substrate and a self-assembly monolayer of SiO2 microspheres. It shows a high and diffusive solar reflectance (96%) and strong infrared-selective emittance (94.6%) with superior spectral effectiveness (1.44). Remarkable subambient cooling of up to 5°C was achieved under high humidity without any solar shading or convection cover at noontime in a subtropical coastal city, Hong Kong. Owing to the all-inorganic hydrophobic structure, the emitter showed outstanding resistance to ultraviolet and water in the long-term durability tests. The scalable solution-based fabrication renders this stable high-performance emitter promising for large-scale deployment in various climates.

Solar-shading systems designed to increase user satisfaction in public buildings, a case study of Britam Towers in Nairobi, Kenya

Solar-shading systems play various roles to the users of public buildings and may vary from user to user but some of the common user’s needs for these systems include; thermal comfort, energy-saving, daylight, and glare reduction. Understanding these needs can help Designers and Architects select from a wide array of Solar-Shading types and see which of them serves the needs of the users better. The Types of Solar-Shading Systems include either internal systems which are placed inside the building or can include external systems which are placed to the outside of buildings. To clearly understand the role Solar Shading Systems, play to satisfy Users’ needs, a case study of a Public Building in Nairobi, Kenya; Britam Towers, was selected. The case study found out that architects, designers, and developers play a preeminent role in coming up with projects that can better serve the User’s needs by creating designs that better suit the needs of the users have for using such Solar-Shading Systems. These designs may vary from building to building, region to region but the main withstanding factor to be noted is the functionality issue, as the Solar-Shading Systems should be able to meet the needs of users effectively and in turn, increase the user’s satisfaction.