Cold Climate Zones Research Articles

Numerical analysis of the subway tunnel thermal environment to predict the train-mounted condenser inlet temperature in the cold climate zone of China

Reasonable control of the subway tunnel thermal environment is the main objective of the ventilation system design, which is critical to the effectiveness of the train-mounted condenser. In this study, a numerical model utilizing the dynamic mesh technique is developed to investigate the subway tunnel thermal environmental characteristics in the cold climate zone of China. Full-scale field measurements are implemented to verify the model’s accuracy. According to the simulation results, the single Piston wind shaft (PWS) (outlet end) is the optimal ventilation system in the cold climate zone of China. The effects of tunnel wall temperature, passenger flow, and regeneration braking system (RBS) efficiency on the subway tunnel thermal environment are thoroughly analyzed, which shows that the tunnel wall temperature has the greatest effect on the air temperature rise of the subway interval tunnel, the passenger flow has the greatest effect on the air temperature rise of the subway station tunnel. In contrast, the RBS efficiency has the least effect on the maximum condenser inlet temperature. On this basis, the predictive model for the maximum and average condenser inlet temperature is proposed. The findings of this study provide a theoretical basis for temperature control in subway tunnels in the cold climate zone of China and contribute to the safe and energy-efficient operation of subway environmental control systems.

Parametric and optimization analyses of a dynamic trombe wall incorporating PCM to save heating energy under cold climate zones

The Trombe wall system incorporating a dynamic PCM layer (DTWPS) has been recognized as a viable envelope to reduce the energy demand for heating effectively. However, properly selecting PCMs in the DTWPS is complicated and much less studied. Therefore, parametric and optimization analyses of the PCM thermal properties of a DTWPS are carried out for heating energy saving under cold climate zones using a validated CFD model, multiple linear and nonlinear regression models, and the particle swarm optimization (PSO) algorithm. The results show nonlinear relationships between the four critical PCM thermal properties and the energy saving, time lag, and thermal comfort. Moreover, the optimal values of the melting point, latent heat, density, and thermal conductivity of the PCM are 26.4 °C, 200 kJ/kg, 2080 kg/m3, and 1.34 W/(m·K), respectively. Meanwhile, the energy saving for the test room equipped with the DTWPS with optimal thermal properties could reach 100 % compared to that for the traditional reference Trombe wall. With available PCMs, heating energy consumption can be saved by up to 90 % or more. Further, the DTWPS demonstrates a reduced PCM mass compared to other passive walls.

A simulation analysis on the internal and external application of new silica-aerogel-based (Quartzene) coatings effects on energy use in a typical building in two different climates

The study investigates the impact of improved synthetic amorphous silica, specifically developed aerogel-based insulating coatings, Quartzene (Qz), on energy efficiency in buildings across cold and warm climate zones. Simulations were conducted on various coatings and thicknesses for exterior and interior wall surfaces, as well as roofs. These were evaluated using a prototype residential building under dynamic thermal conditions. Wall coatings were analyzed, including a base plaster and a mixture with 10%Wt aerogel-based Quartzene. Additionally, three roof coating samples were tested: Qz 12.5%Wt, TiO2 3.3%Wt, and a blend of aerogel-based mixtures and TiO2. Mixtures containing Qz exhibited the lowest thermal conductivity (0.05 W/(m·K)) and high short-wave reflectance (up to 0.93 μm), impacting transmission loads, time lag, and decrement factor. Energy savings of up to 11% were observed in warm climates when implementing the coatings (unaged performance). Overall, the coated surfaces increased time lag and reduced decrement factor compared to uncoated surfaces. Aerogel-based coatings showed enhanced effectiveness in lowering transmission loads.

Proposing design strategies for contemporary courtyards based on thermal comfort in cold and semi-arid climate zones

The relationship between urban geometry and microclimate is crucial in urban planning and climatology, significantly affecting outdoor comfort and energy consumption. Compact, dense buildings provide shading in summer, while openness is preferred in winter to maximize sunlight access. Courtyards, as climate-responsive structures, can create localized microclimates tailored to specific climatic conditions. Various components, including geometry, openness, orientation, wall materials, and green cover, influence the microclimate within a courtyard. While previous studies have primarily focused on hot and arid climates, there is a notable research gap concerning the thermal behavior of courtyards in cold and semi-arid regions. This study seeks to fill this gap by evaluating the impact of different courtyard geometries on outdoor thermal comfort specifically in semi-dry and cold climates by exploring optimal configurations for orientation, form, height-to-width ratios, and plan aspect ratios, the research offers strategies that improve both summer and winter microclimates. The study examined the combined effects of geometry and orientation on shading and wind speed in courtyards, modeling their influence on microclimates during warm summers and cold winters using ENVI-met software. Thermal performance indices, specifically PET and UTCI, were employed to assess the courtyards in Tehran. The findings reveal that a height-to-width ratio of 3:1 significantly improves thermal comfort, resulting in a UTCI difference of 19 °C. Furthermore, the model with a 2:1 plan aspect ratio exhibited a UTCI that was 6.7 °C lower than that of the 3:1 ratio. These findings provide valuable insights for designing contemporary courtyards that optimize thermal comfort in similar climates.

Ediacaran-type non-mineralized tube-dwelling organisms persisted into the early Cambrian (Terreneuvian) in Baltica

The Ediacaran taxon Conotubus hemiannulatus has been discovered in the Terreneuvian blue clays of Estonia. Alongside Conotubus, Gaojiashania-like tubes are also found in these clays. These tubes are fully compressed and pyritized. The well-developed peristomes of Conotubus might have provided stability if the living worm was partially buried in the soft sea floor, suggesting that Conotubus was a sessile suspension feeder. The presence of the archaic Conotubus hemiannulatus in the Fortunian of Estonia indicates that the tube morphology of some cloudinids did not change between the Ediacaran and the Terreneuvian. The existence of these old-fashioned cloudinids in the Terreneuvian suggests either that the early Cambrian ecosystem in Baltica was not significantly different from that of the Ediacaran, or that cloudinids with organic tubes were more resilient to ecological changes than previously thought. Most Terreneuvian faunas originate from lower latitudes, whereas Baltica, during the Terreneuvian, was located at middle-high latitudes and experienced a cold climate. We hypothesize that the cold climate zone ecosystem was more archaic in the Fortunian than the tropical ecosystem, providing a final refuge for the Ediacaran non-mineralized tubicolous organisms. The increased competition pressure from diverse modern animals in the tropics could have driven Ediacaran-type non-mineralized tubicolous organisms to seek refuge in the colder regions of the ocean, where the competition from more advanced animals was less intense.

Effects of environmental changes on soil respiration in arid, cold, temperate, and tropical zones

Soil respiration (Rs) is projected to be substantially affected by climate change, impacting the storage, equilibrium, and movement of terrestrial carbon (C). However, uncertainties surrounding the responses of Rs to climate change and soil nitrogen (N) enrichment are linked to mechanisms specific to diverse climate zones. A comprehensive meta-analysis was conducted to address this, evaluating the global effects of warming, increased precipitation, and N enrichment on Rs across various climate zones and ecosystems. Data from 123 studies, encompassing a total of 10,377 worldwide observations, were synthesized for this purpose. Annual Rs were modeled and their uncertainties were associated with a 1-km2 resolution global Rs database spanning from 1961 to 2022. Calibrating Rs using ensemble machine learning (EML) and employing 10-fold cross-validation, 13 environmental covariates were utilized. The meta-analysis findings revealed an upsurge in Rs rates in response to warming, with tropical, arid, and temperate climate zones exhibiting increases of 12 %, 13 %, and 16 %, respectively. Furthermore, increased precipitation led to stimulated Rs rates of 11 % and 9 % in tropical and temperate zones, respectively, while N deposition affected Rs in cold (+6 %) and tropical (+5 %) climate zones. The machine learning technique estimated the global soil respiration to range from 91 to 171 Pg C yr−1, with an average Rs of 700 ± 300 g C m−2 yr−1. The values ranged between 314 and 2500 g C m−2 yr−1, with the lowest and highest values observed in cold and tropical zones, respectively. Spatial variation in Rs was most pronounced in low-latitude areas, particularly in tropical rainforests and monsoon zones. Temperature, precipitation, and N deposition were identified as crucial environmental factors exerting significant influences on Rs rates worldwide. These factors underscore the interconnectedness between climate and ecosystem processes, therefore requiring explicit considerations of different climate zones when assessing responses of Rs to global change.

The impact of urban dry island on building energy consumption is overlooked compared to urban heat island in cold climate

A large number of literature reveals the impact of urban heat island on building energy consumption, however, the urban dry island impact on the energy demand is very limited. This study aimed to determine the urban–rural disparities in temperature (ΔT) and relative humidity (ΔRH) on sensible and latent heat loads (SHL, LHL) in a large city belonging to the cold climate zone of China. The results showed that apparent ΔT and ΔRH existed between the urban and rural areas, with higher T and lower RH in the urban area compared with those in the rural counterpart. The ΔT of the heating period (1.37 ℃) is far higher than that of the cooling period (0.45 ℃), whereas the ΔRH is almost same in the heating and cooling periods (−9 % vs −8 %). Due to the effect of ΔT, the urban SHL of office building was averagely lower 15.1 % than that in the rural area during the heating period, but only higher 4.6 % in the urban area compared with the rural area in the cooling period. By contrast, the decrease extent of LHL of office building between urban and rural areas in the cooling period (58.7 %) extremely exceeds the increase of LHL in the heating period (6.7 %) due to the ΔRH impact. Negative significant relationships between ΔT and the change of SHL from urban to rural areas, as well as between ΔRH and the change of LHL were found during the heating period, but being positive significant relationships during the cooling period. This study reveals that, in the cold climate zone, the LHL has large contribution to the total energy consumption of buildings, especially the LHL during the cooling period in urban area is much lower than that of the surrounding rural area, highlighting the need to fully consider the LHL in the design and operation of air-conditioning system. In addition, this study shows the potential for improving energy efficiency of other building types or other cities in the cold climate zone by considering the UDI effect.

Thermal performance of solar ground source heat pump system for rural buildings in Chinese cold zone

In response to China's national policy of “achieving carbon peak by 2030 and carbon neutrality by 2060″, and to promote the heating system of rural buildings in China's severe cold zone. Two heating schemes of the GSHP (Ground Source Heat Pump) system and the SGSHP (Solar Ground Source Heat Pump) system are designed and simulated for a single rural residential building in Harbin city. The results present that the outlet temperature of buried pipe in SGSHP system is 13.86 % higher than that in GSHP system, and coefficient of performance (COP) correspondingly increases 9.2 %. There is a better comprehensive performance for the SGSHP system in cold climates. The standard coal consumption of SGSHP system is about 72.35 % less than that of biomass boiler system, showing a greater energy efficiency. Compared to the local conventional biomass boiler system, the dynamic cost payback period of the SGSHP system amounts to 11 years, while yielding a net present value (NPV) of 10,800 CNY throughout the project's life cycle. The emissions of CO2, SO2, and dust are reduced by 2617.13 kg, 19.38 kg, and 14.535 kg respectively. The results indicate a great overall performance of the SGSHP system for residential heating in the cold climate zone. This research offers an energy efficient and eco-friendly alternative for the space heating of Chinese rural buildings in cold climates.

Adaptation of rural residential buildings in a Mediterranean climate to climate change: A case study of La Rioja (Spain)

Climate change is one of the greatest challenges facing the building sector and rural areas in particular should be prioritised due to their special characteristics. In this work, ways to adapt rural residential buildings in a Mediterranean climate to climate change via energy renovation were studied, taking La Rioja (Spain) as a case study. Different energy renovation solutions were evaluated under different climate change scenarios considering the possible evolution of the climate zones. The energy and economic impacts of these energy-renovated buildings were compared to those of existing buildings. Nearly zero-energy buildings were achieved by changing the thermal envelopes and their corresponding interior partitions. The study discovered that, on the one hand, the heating energy demand was reduced while the cooling energy demand was increased, thus reducing the total energy demand; on the other hand, the best energy renovation solution entails compliance by nearly zero-energy buildings with current building thermal regulation for the current climate zone. This work can serve as a guide to establish and promote energy renovation policies that are effective in addressing climate change and are economically viable. Furthermore, the methodology developed and the results obtained can be extrapolated to other cold Mediterranean climate zones.

Mission profile-based assessment of photovoltaic system reliability for Indian climatic zones

ABSTRACT Solar energy is expected to overtake wind energy as the leading renewable energy source by 2050, and therefore, accurate lifetime and reliability predictions for solar photovoltaic (PV) installations are necessary. The microinverter is a pivotal component of stand-alone PV power systems. The reliability of the microinverter depends on the mission profile of the geographical location, such as solar irradiance, ambient temperature, and wind velocity. This study developed a comprehensive reliability map for a 200Wp monocrystalline panel and a 250W microinverter based on mission profile data collected from 198 locations across India. A novel mathematical model is developed and validated using Ansys Icepak to evaluate the junction temperatures of microinverter components. The results show that the junction temperature significantly affects the reliability of PV system. In the hot and dry climatic zone of Jaisalmer, Rajasthan, the maximum MOSFET junction temperature and Mean Time Between Failure (MTBF) obtained were 63.14°C, and 27.34 years, respectively. Furthermore, in the cold and dry climatic zone of Leh, Ladakh, the junction temperature dropped to 29.74°C, increasing MOSFET’s MTBF to 49.8 years. These results prove that the reliability depends on the mission profile, and it should not be ignored in evaluating the reliability of solar PV systems.

Relationship between shape and energy performance of buildings under long-term climate change

The Mediterranean basin is projected to experience the most significant effects of global warming in Europe. As climate change intensifies, resulting in hotter and lengthier summers, there will be a substantial rise in the demand for cooling systems. This study investigates the influence of the surface-to-volume ratio (S/V) in mitigating the impact of climate change on energy performance in Italian buildings, highlighting its often-overlooked status in current research and methodologies. Three different S/V ratio are considered to evaluate the building thermal performance (EPtot,nd) in compliance with the main Italian energy policies (issued in 2005, 2015, 2020) and three different representative Concentration Pathway (RCP) scenarios. The investigation encompasses all national climate zones in Italy. Results vary in relation to national climate zone (from A to F) and standards considered. When comparing EPtot,nd values in 2030 to the ones of 2050 and 2070, hot regions (Zones A, B and C) show an increase in EPtot,nd, reaching a maximum of 20 %, with minimal differences in almost every scenario. The climate zone D displays a varied behavior in EPtot,nd demand, with a trend of reduction for smaller S/V ratios. In climatic zone E, the EPtot,nd demand varies; if there is an increase compared to 2030, it is slight (up to 10 %), and this increase is further mitigated with a low S/V ratio. The cold climate zone F shows a slight reduction in the demand for EPtot,nd in 2050 and 2070, compared to the values required in 2030.

Spatiotemporal Variation and Driving Factors Analysis of Habitat Quality: A Case Study in Harbin, China

Biodiversity is profoundly influenced by habitat quality, and Harbin, a provincial capital situated in a cold climate zone, stands out as one of China’s regions most susceptible to the repercussions of climate change. To ensure the city’s continued sustainable growth, a thorough assessment of habitat quality must be conducted. This study employs a comprehensive approach integrating the InVEST model, the PLUS model, a landscape pattern analysis, geographic detector, and a geographically weighted regression model. The goal is to assess how land use and habitat quality have changed in Harbin City, investigate factors contributing to spatial heterogeneity in habitat quality, thoroughly examine evolutionary patterns under the inertial development scenario from 2030 to 2050, and propose spatial optimization strategies. There are four key findings. First, from 2000 to 2020, agricultural land and forest were Harbin City’s two most prevalent land use types. The most notable transition occurred from forest to grassland, and the expansion of construction land primarily resulted from its encroachment into agricultural areas. Second, within the area of study, the landscape heterogeneity increased while simultaneously experiencing a decrease in connectivity, and the landscape had a tendency toward a more fragmented spatial distribution. Third, overall habitat quality rose between 2000 and 2020 but declined between 2030 and 2050. There was a “weak in the west and high in the east” distribution pattern in the spatial heterogeneity of habitat quality. Fourth, population density has the most impact on habitat quality, with the NDVI and GDP close behind. Conversely, precipitation and slope had comparatively smaller influences on habitat quality. Natural factors combined had a primarily favorable influence on habitat quality across the research region in terms of spatial distribution. Conversely, population density had a discernibly detrimental impact. Given these findings, this study suggests targeted strategies to optimize habitat quality. These recommendations are relevant not only for biodiversity conservation but also for the development of an ecologically sustainable community, particularly in a cold climate region.

Prioritizing Subway Station Entrance Attributes to Optimize Passenger Satisfaction in Cold Climate Zones: Integrating Gradient Boosting Decision Trees with Asymmetric Impact-Performance Analysis

Subway station entrances serve as crucial links between urban environments and underground transit systems and are particularly vital in cities with cold climates. Specialized design strategies are essential to address user needs and promote safety and comfort, thereby encouraging sustainable travel in harsh winter conditions. This research utilizes data from Harbin and Shenyang, two winter cities in China, to explore the nonlinear influences of subway entrance attributes on passenger satisfaction through the combined use of gradient-boosting decision trees and asymmetric impact-performance analysis. The findings indicate that most key attributes of subway entrances impact passenger satisfaction asymmetrically, highlighting the significance of their hierarchical importance in generating satisfaction. These attributes are categorized into frustrators, dissatisfiers, hybrids, satisfiers, and delighters, based on their asymmetry levels. Considering the current performance of these attributes, the study identifies priority for improvement at Harbin and Shenyang’s subway entrances. This aids urban designers and city managers in making informed decisions for urban development and enhancing the overall commuter experience in winter cities.

Observed Changes of Köppen Climate Zones in Spain since 1951

Despite of having been originally formulated more than one hundred years ago, the Köppen classification is still nowadays the climate classification most widely used in climatological studies. Based on the empirical relationship between climate and vegetation, this climate classification provides an efficient and easy way to describe climate conditions and their seasonality by using a simple but ecologically meaningful classification scheme. This study examines the temporal evolution of the Köppen climate classification in Spain for the period 1951-2020, using high-resolution gridded datasets of monthly mean temperature and precipitation with 1 x 1 km spatial resolution. Climate classification maps for consecutive 30-year reference periods are compared, and the temporal evolution of each climate type in Spain is analysed, showing a progressive expansion of the arid climate zones and a contraction of the cold climate zones along the study period.

First record of the plant bug genus Punctifulvius Schmitz from the Oriental Region, with descriptions of three new species (Hemiptera, Heteroptera, Miridae, Cylapinae).

Three new species of the fungal-inhabiting plant bug genus Punctifulvius Schmitz, 1978 (Cylapinae: Fulviini) are described, namely P. aleksanderi n. sp. from Selangor, Malaysia, P. parvus n. sp. from East Kalimantan, Indonesia, and P. sakaerat n. sp. from Nakhon Ratchasima, Thailand. The present discovery represents the first record of the genus from the Oriental Region. Punctifulvius members are now confirmed to be widespread from the cold temperate climatic zones in the eastern Palearctic regions, across the tropics of the Oriental Region, to the temperate rainforest of Australia. Punctifulvius kerzhneri Schmitz, 1978 is recorded from Taiwan for the first time. The systematic position of Teratofulvioides Carvalho & Lorenzato, 1978 is discussed, and its single species Teratofulvioides punctatus Carvalho & Lorenzato, 1978 is redescribed. Color adult habitus images of Punctifulvius aleksanderi, P. kerzhneri, P. parvus, P. sakaerat, and Teratofulvius punctatus, images of male (P. parvus and P. sakaerat) and female (P. aleksanderi) genitalic structures, as well as scanning electron micrographs of selected structures of P. aleksanderi, P. kerzhneri, P. parvus, P. sakaerat, and T. punctatus are provided. Key to the species of Punctifulvius is given.

Niche-dependent microbial assembly in salt-tolerant tall fescue and its contribution to plant biomass

Tall fescue (Festuca arundinacea Schreb.) is promising for biogas production in cold climate zones and displays good performance and high biomass under moderate to severe salt stress. The plant microbiome is crucial for enhancing plant growth and boosting crop yield under salt stress. To determine the variations of microbiome composition and abundance in different plant compartments with salt-tolerant tall fescue cultivars under salt stress, this study performed 16S ribosomal RNA amplicon and internal transcribed spacer (ITS) sequencing. Moreover, the study investigated the effect of enriched bacteria on tall fescue growth and salt tolerance. The aboveground and belowground compartments shaped distinct and overlapping microbial communities, as evidenced by the fact that Proteobacteria and Ascomycota displayed various preferences in inhabiting each compartment. Salt stress drove significant changes in microbiome composition in different compartments. Interestingly, the abundance and diversity of bacteria varied more significantly than those of fungi in response to salt stress. Microbes may enhance the carbon fixation pathways in prokaryotes and flagellar assembly functions to improve the salinity tolerance of tall fescue. Moreover, the inoculation experiment revealed that Halomonas lutescens could promote plant salt tolerance and biomass accumulation. Taken together, this research presents clear insight regarding the dynamics of plant microbiome recruitment in different tall fescue compartments under salt stress and highlights the role of the microbes in regulating plant salt tolerance, thus offering huge potential for increasing the resilience of crop and bioenergy production in agriculture and industry to salt stress.

Development of a nano-size off-grid energy system using renewables and IoT technologies at the Meteoria visitor center: A Finnish case study

The increased utilization of non-renewable energy during the last century has influenced the climate, with increased carbon dioxide emissions and elevated temperature as a result. Thus, the need to develop and demonstrate new sustainable solutions regarding both energy supply and consumption, but also energy system optimization, is obvious. This case study presents the nano-size off-grid energy system at the Meteoria visitor center in Ostrobothnia, Finland, and the real-time measuring techniques that have been installed to follow up the energy production and consumption. The Meteoria consists of several buildings, which are open to the public from April to October. The case site is operated by energy derived from wind power, solar power, and a diesel generator (as a backup), with batteries for energy storage. The Internet of Things (IoT) has been retrofitted to the existing energy system to enable energy measurements and follow various electrical parameters in real-time. In addition, a graphical visualization platform open to the public has been developed. In this study, the completeness of data sampling and the IoT system was checked, and the results show high availability of data. Furthermore, various errors/limitations regarding the IoT system were identified. The energy supply/demand at the Meteoria in 2021 was monitored and the challenges regarding the existing energy system in a cold climate zone are discussed as well as the potential role of the Meteoria to function as a living lab.

Optimizing automated shading systems for enhanced energy performance in cold climate zones: Strategies, savings, and comfort

Enhancing urban sustainability requires innovative strategies to improve energy performance while maintaining occupant comfort in new and existing buildings. Buildings located in cold climate zones with high glazing-to-wall ratios often face unwanted solar gain and heat loss that, in turn, negatively impact building energy performance. Though automated shading systems effectively reduce excessive indoor solar gain in warm climates, a research gap exists regarding their ability to enhance building energy performance in heating-dominant climates. This paper investigates automated shading implementation for cold climate zones and develops a novel cold climate optimized sensorless control strategy for interior roller shades. A field study was conducted to assess the impact of roller shade operation on indoor thermal conditions. Results from the field study showed that the prototype roller shades operating on the developed control strategy reduced daytime indoor peak temperatures during the summer season to 26.4 °C ± 0.5 °C from 30.0 °C ± 1.9 °C and 28.5 °C ± 1.2 °C for the unshaded and shaded static operation baseline scenarios, respectively. During winter season tests, shade deployment reduced the overnight indoor cooling rate from 0.60 °C/hr ± 0.30 °C/hr and 0.42 °C/hr ± 0.18 °C/hr. A mathematical model was also developed to estimate shading system energy performance based on user-defined building specifications and weather-related variables. It was found that automated shading systems are suitable for use as a green retrofit strategy for cold climate zone buildings. The technology exhibited a payback period range of approximately 5–15 years, depending on factors such as glazing type, glazing orientation, solar exposure, and local climate conditions. Findings from both the simulation and prototype field study support the use of cold climate-optimized automated shading systems to improve overall building energy performance - reducing both building heating and cooling-related energy consumption.

Enhancing learning Environments: Exploring optimal classroom design connected to Double-Loaded corridors across the U.S. Climate zones

Buildings’ envelope design decisions are usually determined by the architect or designer from the early stages of design. These decisions have a major impact on the comfort conditions and energy performance of buildings. Balancing daylighting levels in school buildings with the energy use is essential due to the physiological, psychological, and behavioral effects of daylight on human body, known as the non-image forming (NIF) effects of light, as well as its impact on the energy use. This study uses multi-objective optimization (MOO) to find the optimal classroom design that has the best overall performance in terms of daylighting levels at the horizontal desk-plane for image-forming (IF) or visual benefits, daylighting at the vertical eye-level for NIF benefits, and the total energy use of classrooms. The study optimizes two classrooms connected to double-loaded corridor from the Department of Energy (DOE) primary school reference building. The optimization parameters include the classroom geometry (width, depth, and height), the window dimensions (width and head height), and the orientation. The impact of the location factor is explored by optimizing the same model in the mixed-humid, hot-humid, hot-dry, and cold climate zones of the U.S. The results indicate that the 3:2 width-to-depth plan shape in most optimal solutions performs better than the 5:4 width-to-depth plan of the reference model. Accordingly, wider windows and higher head height in the optimal design were able to allow more daylighting to the depth of the oppositely oriented classrooms while reducing the energy use. The results show that optimal classrooms’ design connected to double-loaded corridors, including window dimensions, orientation, and window to wall ratio (WWR) vary by the climate zone or location.

Multi-objective optimization for the daylighting and thermal comfort performance of elevated subway station buildings in cold climate zone of China

The rapid development of urban rail transit brings about the rapid growth of elevated subway station buildings, while the demand for comfortable waiting environments on the passenger platforms is also increasing. Due to the fact that elevated stations generally have a transparent envelope, there is a contradiction between daylighting, heating, and air conditioning. Therefore, multi-objective optimization design is essential. This article selects the cold regions of northern China as the research object. A field investigation was carried out, and Tianjin University Town Station was found to be a typical station in cold climate zone of China. A prototypical model was built based on it using Grasshopper in Rhino. Sensitivity analysis was used to screen key independent variables, and strength Pareto evolutionary algorithm II was used to optimize the daylighting and thermal comfort performance for the elevated subway station buildings. Two optimization processes, step-by-step and one-step, were used to obtain the non-dominated solution set, and the optimal solution was obtained by technique for order preference by similarity to an ideal solution analysis. The suggested values for the design variables of the prototypical model are also displayed. Reducing the skylight's window-to-wall ratio helps improve daylighting and thermal comfort. Besides, the one-step optimization method has higher efficiency and can obtain better results. The findings proposed here can guide the development of elevated subway station buildings in north China and other areas with similar conditions.