Search Results (34)

Energy conservation and carbon reduction in buildings have become important concerns and, at the same time, the value of low-tech approaches employed in indigenous architecture is increasingly acknowledged as a pertinent reference for contemporary design practices. The research on vernacular dwellings in Jiangxi has many perspectives and fruitful results, but not enough attention has been paid to the research on climate adaptation. This article verifies the vernacular dwellings’ climate adaptation and summarizes the low-tech methods embedded in vernacular dwellings, aiming to provide guidelines for future exploration of energy-saving and carbon-reducing practices in architecture. By selecting different types of vernacular dwellings in Nanfeng County, this article verifies three aspects of the ecological characteristics of vernacular dwellings: the light environment, wind environment, and energy consumption, by comparing them with those of local modern residential buildings. It is concluded that the average daylight factor of the hall area of vernacular dwellings is better than that of the modern residential buildings in rural areas, and the vernacular dwellings regulate the indoor wind environment and maintain indoor comfort through natural ventilation in winter and summer seasons. Also, the annual energy consumption of the vernacular dwellings per unit area per year can be reduced by up to about 32% in comparison with modern residential buildings. Subsequently, the article concludes that patio space has a positive impact on the indoor physical environment through comparative experiments. Vernacular dwellings are well adapted to the local climate in terms of form, structure, and materials, and these low-tech methods should be applied to the design of rural dwellings in the future. Full article

The advancement of technology has significantly improved energy measurement systems. Recent investment in smart meters has enabled companies and researchers to access data with the highest possible temporal disaggregation, on a minute-by-minute basis. This research aimed to obtain data with the highest possible temporal and spatial disaggregation. This was achieved through a process of energy consumption measurements for six devices within seven houses, located in different communes (counties) of the Metropolitan Region of Chile. From this process, a data panel of energy consumption of six devices was constructed for each household, observed in two temporal windows: one quarterly (750,000+ observations) and another semi-annual (1,500,000+ observations). By applying a panel data econometric model with fixed effects, calendar-temporal patterns that help explain energy consumption in each of these two windows have been studied, obtaining explanations of over 80% in some cases, and very low in others. Sensitivity analyses show that the results are robust in a short-term temporal horizon and provide a practical methodology for analyzing energy consumption determinants and load profiles with panel data. Moreover, to the authors’ knowledge, these are the first results obtained with data from Chile. Therefore, the findings provide key information for the planning of production, design of energy market mechanisms, tariff regulation, and other relevant energy policies, both at local and global levels. Full article

Introduction: Many factors related to the switch to summer/winter time interfere with biological rhythms. Objectives: This study aimed to analyze the impact of time change on clinical outcomes of patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). Patients and methods: Electronic data of 874,031 patients with ACS who underwent invasive procedures were collected from the Polish National Register of Interventional Cardiology Procedures (ORPKI) between 2014 and 2021. We determined the number of patients undergoing PCI and periprocedural mortality during the day of spring or autumn time change and within the first 3 and 7 days after the time change. Results: We demonstrated the impact of time changes on the periprocedural mortality of ACS patients within 1 day and the period of 3 and 7 days from the time change. We observed that the occurrence of all ACS and NSTEMI on the first day was lower for both time changes and higher in the case of UA and spring time change. The autumn time change significantly reduced the occurrence of all types of ACS. A significant decrease in the number of invasive procedures was found after autumn transition in the period from the first day to 7 days for ACS, NSTEMI, and UA. Conclusions: The occurrence of ACS and the number of invasive procedures were lower for both changes over time. Autumn time change is associated with increased periprocedural mortality in ACS and a less frequent occurrence of UA and NSTEMI within 7 days. Full article

Background: Permanent Daylight Savings Time (DST) may improve road safety by providing more daylight in the evening but could merely shift risk to morning commutes or increase risk due to fatigue and circadian misalignment. Methods: To identify how potential daylight exposure and fatigue risk could differ between permanent DST versus permanent Standard Time (ST) or current time arrangements (CTA), generic work and school schedules in five United States cities were modeled in SAFTE-FAST biomathematical modeling software. Commute data were categorized by morning (0700–0900) and evening (1600–1800) rush hours. Results: Percent darkness was greater under DST compared with ST for the total waking day (t = 2.59, p = 0.03) and sleep periods (t = 2.46, p = 0.045). Waketimes occurred before sunrise 63 ± 41% percent of the time under DST compared with CTA (42 ± 37%) or ST (33 ± 38%; F(_2,74) = 76.37; p < 0.001). Percent darkness was greater during morning (16 ± 31%) and lower during evening rush hour (0 ± 0%) in DST compared with either CTA (morning: 7 ± 23%; evening: 7 ± 14%) or ST (morning: 7 ± 23%; evening: 7 ± 15%). Discussion: Morning rush hour overlaps with students’ commutes and shift workers’ reverse commutes, which may increase traffic congestion and risk compared with evening rush hour. Switching to permanent DST may be more disruptive than either switching to ST or keeping CTA without noticeable benefit to fatigue or potential daylight exposure. Full article

This study aimed to promote the use of natural lighting in building designs to create a good lighting environment and to save energy. Dynamic daylight evaluation and analysis have become hot research topics due to the influence of outdoor light climate changes that occur throughout the season and over a period of time. However, there are certain gaps in the application of dynamic daylight evaluation for large-space buildings. In China, static daylight evaluation is mainly used to assess the actual daylighting performance of buildings. The Hangzhou E-sports Center in China was selected as the study object in this research, and dynamic daylight simulations were conducted using Rhino + Grasshopper and Ladybug + Honeybee for different representative days in each season and in each measurement zone. Spatial daylight autonomy (sDA) and useful daylight illuminance (UDI) were used as the dynamic daylight evaluation indicators, and a parameterized dynamic daylight evaluation method was proposed for evaluating the design scheme. By comparing the initial and optimized design schemes, the results showed the following: (1) the optimized scheme increased the ratio of area and time within the UDI 100–2000 lux range, and areas with an sDA >300 lux accounted for over 55% of the primary use areas, indicating a significant improvement in the daylighting quality of the large space; (2) the daylighting quality of the large space building showed seasonal changes, with the best daylighting quality occurring during the summer solstice and the worst occurring on the winter solstice, while the daylighting quality was similar during the spring and autumn equinoxes; (3) the dynamic evaluation metrics facilitated the identification of daylighting issues in large-scale buildings more effectively; (4) the parameterized method proposed in this study can solve the cumbersome process of daylight simulation and is more conducive to the adjustment and optimization of design schemes by designers. The parameterized dynamic daylight evaluation method proposed in this study provides references and ideas for the design and research of daylighting in other large-space buildings. Full article

Some municipalities switch off street lights for several hours at night to save energy and reduce operating costs as a consequence of soaring electricity prices in Europe. Complete darkness in the streets raises public concern about safety and security. The current street lighting standard EN 13201 enables the road luminance to be reduced in parallel with diminishing traffic volume offering a viable tradeoff between energy saving and road safety. This paper presents a methodology to estimate the energy-saving potential of traffic-regulated street lighting based on traffic counting data. By analyzing traffic volume and composition collected from an urban street over the one-year period, we found that traffic sensor-regulated street lighting can deliver up to 55% reduction in electricity costs while maintaining road luminance in line with the recommendations of EN 13201-2. In the presented case, the daily traffic volume profiles were remarkably stable following either a workday or a holiday pattern. Statistical analysis showed that 45% energy saving could be achieved by the pre-programmed dimming schedule of the luminaires while remaining compliant with the standard. The effect of daylight-saving time on the energy consumption of adaptive street lighting was also analyzed. Full article

Virtual sensing technology uses mathematical calculations instead of natural measurements when the latter are too difficult or expensive. Nowadays, application of virtual light sensing technology becomes almost mandatory for daylight analysis at the stage of architectural project development. Daylight Autonomy metrics should be calculated multiple times during the project. A properly designed building can reduce the necessity of artificial lighting, thus saving energy. There are two main daylight performance metrics: Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE). To obtain their values, we have to simulate global illumination for every hour of the year. A light simulation method should therefore be as efficient as possible for processing complex building models. In this paper we present a method for fast calculation of Daylight Autonomy metrics, allowing them to be calculated within a reasonable timescale. We compared our method with straightforward calculations and other existing solutions. This comparison demonstrates good agreement; this proves sufficient accuracy and higher efficiency of the method. Our method also contains an original algorithm for the automatic setting of the sensing area. The sDA metric is calculated considering blinds control, which should open or close them depending on overexposure to direct sunlight. Thus, we developed an optimization procedure to determine the blinds configuration at any time. Full article

Owing to the special tubular structural characteristics of highway tunnels, drivers typically experience a significant change in visual luminance when entering tunnels, which seriously impacts driving safety. This paper proposes a lighting scheme based on optical fiber technology to introduce natural light into the tunnel portal section. First, an on-demand lighting scheme based on the use of daylight is designed by developing an optical fiber lighting system, lighting demand algorithm, and an on-demand lighting control scheme. Furthermore, the scheme is applied to a physical tunnel, and the safety and energy-saving potential of the scheme are analyzed based on the obtained data. The results indicate that the average luminance and luminance uniformity in the tunnel portal section appear to improve with the application of the proposed scheme; the luminance uniformity is particularly increased by 0.18. The correlative color temperature (CCT) of the environment inside the cave changes in real time with the CCT value of the phase pair outside the cave. Compared with the explicit use of electrical lighting, the lighting energy consumption during daytime can be reduced by 34.7% with the application of the proposed scheme, and the highest reduction of 79.8% can be achieved at 13:00. Full article

Although there is a documented preference for daylighting over artificial electric lighting indoors, there are comparatively few investigations of behaviour and perception in indoor day-lit spaces at high latitudes during winter. We report a pilot study designed to examine the effects of static artificial lighting conditions (ALC) and dynamic daylighting conditions (DLC) on the behaviour and perception of two groups of participants. Each group (n = 9 for ALC and n = 8 for DLC) experienced one of the two conditions for three consecutive days, from sunrise to sunset. The main results of this study show the following: indoor light exposure in February in Stockholm can be maintained over 1000 lx only with daylight for most of the working day, a value similar to outdoor workers’ exposure in Scandinavia; these values can be over the recommended Melanopic Equivalent Daylight Illuminance threshold; and this exposure reduces sleepiness and increases amount of activity compared to a static artificial lighting condition. Mood and feeling of time passing are also affected, but we do not exactly know by which variable, either personal or group dynamics, view or variation of the lighting exposure. The small sample size does not support inferential statistics; however, these significant effects might be large enough to be of importance in practice. From a sustainability point of view, daylighting can benefit energy saving strategies and well-being, even in the Scandinavian winter. Full article

Several studies have investigated the relationship between daylight saving time (DST) and sleep alterations, psychiatric disorders, cardiovascular events and traffic accidents. However, very few have monitored participants while maintaining their usual lifestyle before and after DST. Considering that DST transitions modify human behavior and, therefore, people’s light exposure patterns, the aim of this study was to investigate the potential effects of DST on circadian variables, considering sleep and, for the first time, the human phase response curve to light. To accomplish this, eight healthy adults (33 ± 11 years old, mean ± SD) were recruited to monitor multivariable circadian markers and light exposure by means of a wearable ambulatory monitoring device: Kronowise^®. The following night phase markers were calculated: midpoints of the five consecutive hours of maximum wrist temperature (TM5) and the five consecutive hours of minimum time in movement (TL5), sleep onset and offset, as well as sleep duration and light intensity. TM5 for wrist temperature was set as circadian time 0 h, and the balance between advances and delays considering the phase response curve to light was calculated individually before and after both DST transitions. To assess internal desynchronization, the possible shift in TM5 for wrist temperature and TL5 for time in movement were compared. Our results indicate that the transition to DST seems to force the circadian system to produce a phase advance to adapt to the new time. However, the synchronizing signals provided by natural and personal light exposure are not in line with such an advance, which results in internal desynchronization and the need for longer synchronization times. On the contrary, the transition back to ST, which implies a phase delay, is characterized by a faster adaptation and maintenance of internal synchronization, despite the fact that exposure to natural light would favor a phase advance. Considering the pilot nature of this study, further research is needed with higher sample sizes. Full article

Implementation of Daylight Savings Time (DST) started in various jurisdictions during the first half of the 20th century. Much debate on the merits of the twice-yearly change in the official local time has ensued since then regarding energy usage, sleep patterns, health outcomes, traffic safety, etc. The DST switch in the official time abruptly shifts anthropogenic emissions that are related to human activities relative to the Coordinated Universal Time (UTC) but does not affect meteorological processes that disperse them, which day-to-day variability is affected by longer time scales. Here, we utilized the DST clock changes as a repeating biannual experiment to study the impact of meteorology on air pollution. We analyzed traffic volume data and up to 20 years of nitrogen oxides (NOx), fine particulate matter (PM_2.5), ozone (O₃) and carbon monoxide (CO) concentrations, observed at different air quality monitoring (AQM) stations in Israel, demonstrating a clear and significant impact of the daily meteorological cycle on traffic related air pollution (TRAP). In particular, traffic emissions are prerequisite for TRAP, but meteorology was found to dominate the daily patterns of the NOx, O₃ and CO concentration fields in the study area. On the other hand, the impact of vehicle emissions on PM_2.5 concentrations seems to be very small. Our results highlight the multiscale interplay between pollutant emissions and dispersion processes, especially for pollutants that are emitted near the surface. We demonstrate that while DST clock changes do not affect the emissions intensity, nor the meteorological processes vigor, they do shift human activity-related emissions with respect to the DST-blind dispersion processes. This results in short-term effects on primary traffic-related pollutant concentrations that cancel out over the day, and a consistent yet small effect on secondary traffic-related pollutant concentrations (O₃). Full article

The goal of the current study was to determine the appropriate spatial shapes for classroom occupants while saving energy. The research used parametric design and Genetic Algorithm (GA) to achieve this. Four recognized performance indicators, Energy Use Intensity (EUI), Useful Daylight Illuminance (UDI), Daylight Factor (DF), and Daylight Autonomy (DA), were used as the evaluation indexes for the research. The tests took place in six east–west-oriented classrooms at Shanghai University, China. The methodology was based on four steps: (1) parametric 3D modeling by Rhino and Grasshopper; (2) using building performance simulation tools; (3) running algorithm optimization; (4) outputting the useful results. The results proved that the methodology worked successfully in reducing energy consumption: optimized classrooms could be reduced by 7.5~14.5%, and classrooms with east directions were generally 4.8~8.3% more efficient than west-facing ones. The indoor lighting environment was also significantly improved, being slightly better than north–south-oriented classrooms in terms of the UDI index (60~75%) and inferior (but still high) in terms of the DF (4.0~7.0%) and DA (60~80%) indexes. The conclusion can help save design time in the early design process of teaching spaces. Full article

Considering the comprehensive effect of building carbon emissions, cost savings is of great significance in nearly-zero-energy buildings (NZEBs). Previous research mostly focused on studying the impact of technical measures in pilot projects. The characteristics of different cities or climate zones have only been considered in a few studies, and the selection of cities is often limited. At times, only one city is considered in each climate zone. Therefore, this study selected 15 cities to better cover climate zone characteristics according to the variation in weather and solar radiation conditions. A pilot NZEB project was chosen as the research subject, in which the energy consumption was monitored and compared across different categories using simulated values by EnergyPlus software. Various NZEB technologies were considered, such as the high-performance building envelope, the fresh air heat recovery unit (FAHRU), demand-controlled ventilation (DCV), a high-efficiency HVAC and lighting system, daylighting, and photovoltaic (PV). The simulated carbon emission intensities in severe cold, cold, and hot summer and cold winter (HSCW) climate zones were 21.97 kgCO₂/m², 19.60 kgCO₂/m², and 15.40 kgCO₂/m², respectively. The combined use of various NZEB technologies resulted in incremental costs of 998.86 CNY/m², 870.61 CNY/m², and 656.58 CNY/m². The results indicated that the HSCW region had the best carbon emission reduction potential and cost-effectiveness when adopting NZEB strategies. Although the incremental cost of passive strategies produced by the envelope system is higher than active strategies produced by the HVAC system and lighting system, the effect of reducing the building’s heating load is a primary and urgent concern. The findings may provide a reference for similar buildings in different climate zones worldwide. Full article

Lighting control systems (LCSs) play important roles in maintaining visual comfort and energy savings in buildings. This paper presents a prototype LCS using LabVIEW with real-time high dynamic range images and a digital multiplex controller to brighten lamps sequentially to provide visual comfort. The prototype is applied to a scaled classroom model with three schemes involving different activities and needs: writing and reading, requiring a uniform luminance of approximately 100 cd/m², teaching using a whiteboard, requiring an illuminance of approximately 120 cd/m² for the whiteboard and 60 cd/m² for the desks, and drawing and art activities focused on the center of the room, requiring an illuminance of approximately 100 cd/m² for the center area and 50 cd/m² for the background area. For each scheme, two conditions are presented: one in which the room is treated as a closed room without windows, and the one in which the room has a large window on one wall that enables daylight to penetrate the room. The prototype works well with both schemes and provides different combinations of lamp brightness levels, starting from 10% to 60%, based on the activities and required luminance, and can save around 73–82% of electricity. The presence of daylight does not always result in more energy savings, as the brightness contrast for visual comfort needs to be considered. Full article

(1) Background: Approximately 73 countries worldwide implemented a daylight saving time (DST) policy: setting their clocks forward in spring and back in fall. The main purpose of this practice is to save electricity. The aim of the present study was to find out how DST affects the incidence and impact of seriously injured patients. (2) Methods: In a retrospective, multi-center study, we used the data recorded in the TraumaRegister DGU^® (TR-DGU) between 2003 and 2017 from Germany, Switzerland, and Austria. We compared the included cases 1 week before and after DST. (3) Results: After DST from standard time to summertime, we found an increased incidence of accidents of motorcyclists up to 51.58%. The result is consistent with other studies. (4) Conclusion: However, our results should be interpreted as a tendency. Other influencing factors, such as time of day and weather conditions, were not considered. Full article