Outdoor Climatic Conditions Research Articles

Measured hygrothermal performance of energy activated facade in cold climate

This study assesses the hygrothermal performance of the Photovoltaic External Thermal Insulation Composite System (PV ETICS), using a thick layer of mortar with Phase Change Material (PCM) granules as a passive heat sink. The experimental scenario involved the wall system exposure to real outdoor climate conditions during a 20-month long measurement period. Measured data were compared with results from the hygrothermal modelling. The findings reveal that with carefully designed diffusion channels the PV ETICS demonstrated no accumulation of moisture behind the vapour-tight PV panel. Long term hygrothermal modelling for PCM mortar moisture content with a previously calibrated model predicted stable moisture content around 0.03 m3/m3, significantly lower than the moisture content during first 2 years. Relative humidity behind the PV panel falls into the hygroscopic range on the second spring after the construction. The annual maximum temperatures for PCM mortar during two summers were 69°C, occurring in mid-August. Risk analysis was conducted with historic climate data to understand, whether higher PCM temperatures could be reached in the same climate for different years. Overall, the wall system showed no signs of extensive moisture damage during the testing period, but slight discolouring of the PCM mortar was recorded. This study contributes valuable insights into the practical viability of PV ETICS with PCM mortar, reaffirming its potential for application on larger scale on real building facades.

Methods of determining thresholds of climate variables in building thermal design zoning in China

Climate variable thresholds (CVTs) are essential for building thermal design zoning (BTZ). However, the CVTs in the current BTZ are no longer suitable for developing the current building design. Therefore, the calculation method of bidirectional optimization zone index division standard is established: Forward optimization to obtain the outdoor threshold value that meets the indoor temperature calculation; Reverse optimization to obtain the distribution trend of the combined form of the envelope structure under the known indoor calculated temperature and outdoor climate conditions. According to the new calculation method, the outdoor heating threshold temperatures (OHTT) are adjusted from the original 5 °C–10 °C. In addition, CVTs are updated for significant subregions, such as: 1) the CVT for the hot summer and cold winter and hot summer and warm winter zone is calculated as 10 °C; 2) the CVT for severe cold (SCZ) and cold zones (CZ) is updated to −8 °C. These results will support the development of a BTZ and provide a scientific basis for reforming the heating method in China.

Effects of winter climate parameters on the thermal performance of dynamic rotating latent-energy-storage envelope (DRLESE)

The accurate application of the Dynamic Rotating Latent-Energy-Storage Envelope (DRLESE) system necessitates careful consideration of outdoor climate conditions, which significantly impacted latent heat operation of Phase-Change Materials. The effects of climate parameters were explored by considering five convective heat transfer coefficients ranging from 10 W/(m·K) to 30 W/(m·K), six daily solar radiation intensities ranging from 15.0 MJ/Day to 30.0 MJ/Day, six air average temperatures ranging from −10.0°C to 15°C, and six fluctuation ranges of air temperature ranging from 5°C to 20°C. The thermal performance of the DRLESE system was evaluated by employing the liquid fraction of Phase-Change Materials (PCM), the thermal quantity of DRLESE, and the inner surface heat flow. The numerical results demonstrated that climate parameters have a profound effect on the thermal performance of the DRLESE system. Enhancing convective heat transfer coefficient or lowering outdoor air temperature can significantly attenuate thermal performance by promoting convective thermal dissipation, while increasing daily solar radiation intensity can provide ample solar radiation for absorption by the DRLESE system. With convective heat transfer coefficient increased from 10 W/(m2·K) to 20 W/(m2·K), the daily solar radiation intensity increased from 15MJ/Day to 30MJ/Day, outdoor air temperature increased from −10°C to 15°C, the fluctuation range increased from 5°C to 20°C, indoor effective thermal release was increased −55.38 %, 204.66 %, 241.00 % and 8.11 %, respectively. In addition, employing the transparent covers and selecting the appropriate PCM were recommended to enhance thermal performance of the DRLESE system.

Climate change and heat stress resilient outdoor workers: findings from systematic literature review

PurposeGlobal warming has led to an increase in the number and intensity of extreme heat events, posing a significant threat to the health and safety of workers, especially those working outdoors, as they often have limited access to cooling strategies. The present systematic literature review (a) summarizes the current knowledge on the impacts of climate change on outdoor workers, (b) provides historical background on this issue, (c) explores factors that reduce and increase thermal stress resilience, (d) discusses the heat mitigation strategies, and (e) provides an overview of existing policy and legal frameworks on occupational heat exposure among outdoor workers.Materials and methodsIn this systematic review, we searched scientific databases including Scopus (N = 855), Web of Science (N = 828), and PubMed (N = 202). Additionally, we identified relevant studies on climate change and heat-stress control measures through Google Scholar (N = 116) using specific search terms. In total, we monitored 2001 articles pertaining to worker populations (men = 2921; women = 627) in various outdoor climate conditions across 14 countries. After full-text assessment, 55 studies were selected for inclusion, and finally, 29 eligible papers were included for data extraction.ResultsFailure to implement effective control strategies for outdoor workers will result in decreased resilience to thermal stress. The findings underscore a lack of awareness regarding certain adaptation strategies and interventions aimed at preventing and enhancing resilience to the impact of climate change on heat stress prevalence among workers in outdoor tropical and subtropical environments. However, attractive alternative solutions from the aspects of economic and ecological sustainability in the overall assessment of heat stress resilience can be referred to acclimatization, shading, optimized clothing properties and planned breaks.ConclusionThe integration of climate change adaptation strategies into occupational health programs can enhance occupational heat resilience among outdoor workers. Conducting cost-benefit evaluations of health and safety measures for thermal stress adaptation strategies among outdoor workers is crucial for professionals and policymakers in low- and middle-income tropical and subtropical countries. In this respect, complementary measures targeting hydration, work-rest regimes, ventilated garments, self-pacing, and mechanization can be adopted to protect outdoor workers. Risk management strategies, adaptive measures, heat risk awareness, practical interventions, training programs, and protective policies should be implemented in hot-dry and hot-humid climates to boost the tolerance and resilience of outdoor workers.

Energy-Efficient Production of Microchloropsis salina Biomass with High CO2 Fixation Yield in Open Thin-Layer Cascade Photobioreactors

Lipid production using microalgae is challenging for producing low-value-added products. Harnessing microalgae for their fast and efficient CO2 fixation capabilities may be more reasonable since algal biomass can be utilized as a precursor for various products in a biorefinery approach. This study aimed to optimize the productivity and efficiency of Microchloropsis salina biomass production in open thin-layer cascade (TLC) photobioreactors under physical simulation of suitable outdoor climate conditions, using an artificial seawater medium. Continuous operation proved to be the most suitable operating mode, allowing an average daily areal productivity of up to 27 g m−2 d−1 and CO2 fixation efficiency of up to 100%. Process transfer from 8 m2 to 50 m2 TLC photobioreactors was demonstrated, but with reduced daily areal productivity of 21 g m−2 d−1 and a reduced CO2 fixation efficiency, most probably due to increased temperatures at midday above 35 °C. An automated overnight switch-off of the circulation pumps was implemented successfully, reducing energy and freshwater requirements by ~40%. The ideal conditions for continuous production were determined to be a dilution rate of 0.150–0.225 d−1, pH of 8.5, and total alkalinity of 200–400 ppm, facilitating efficient pilot-scale production of microalgal biomass in TLC photobioreactors.

Impact of heating strategies towards energy-efficient buildings

Mitigating climate change and its impact requires intensive efforts to reduce greenhouse gas emissions, transition to renewable energy sources, and implement sustainable practices. Intermittent heating is considered a sustainable and effective way to achieve energy savings compared with continuous heating mode. However, recent studies have found that energy savings from intermittent heating depend on several factors, namely the building envelope solution. Therefore, this work intends to fill the research gap by comparing the energy efficiency and thermal performance of different construction systems, using two real-scale test cells, one built with a Light Steel Framing (LSF) solution and the other with concrete and Hollow Brick Masonry (HBM) solution. An experimental monitoring campaign was performed during the heating season, aimed at analysing the energy consumption, the responsiveness of the test cells to the heating system, and the influence of the outdoor climate on energy consumption, considering different heating strategies (intermittent patterns and continuous). In general, the LSF test cell registered lower energy consumption when compared to the HBM test cell. However, the LSF test cell presented significant fluctuations of the indoor temperature, confirming that it is more susceptible to the outdoor climate conditions. This research concluded that a system with lower thermal inertia has superior energy saving potential.

Reversed cooling and heating performance of modernized courtyard envelope in hot-arid climates: a case study at an educational campus

Courtyard buildings embraced as a passive design paradigm, find wide application in modulating outdoor climatic conditions and fostering energy efficiency. Consequently, exploring passive strategies to mitigate the repercussions of climate change becomes a compelling priority. However, previous studies have predominantly emphasized the daytime performance of traditional courtyards in hot climates, often overlooking their performance throughout the entire day. This oversight includes the impact of courtyards in releasing stored heat into the air during nighttime, commonly referred to as "the reversed impact of the courtyard." This study evaluates the reversed thermal impact of glazed “modernized” courtyard envelope during nighttime and day-exposed radiation. This analysis considers the complex interaction between incoming and outgoing radiation flows. The study employed a combined approach involving onsite measurements and numerical simulations centered upon an educational building within a hot-arid zone. The scope of the study encompasses diverse courtyard geometries and various mitigation strategies, all characterized by heightened proportions of glazed surface areas. The results, depending on prevailing weather conditions, reveal the potential for these factors to reduce heating time from 17 h to just 2 h at the optimum. In contrast, there is an increase in cooling impact, ranging from 7 to 22 h throughout both day and night, with scenarios representing the least and most favorable cases, respectively. For designing processes, optimizing aspect ratio without exceeding 1.6 and glazed façade orientation is essential to control multi-reflection at the modernized courtyard envelope criteria.Graphical abstract

Computation of corona generated ionic current environment of unipolar UHVDC transmission lines using gas bimolecular collision theory

Corona on UHVDC transmission line conductors initiates corona power loss and the inevitable ionic current flow environment at ground level. To limit this substantial flow of ionic current at ground levels, it is necessary to establish an appropriate line design configuration, including the diameter of the line conductor and the height level above the ground. It is a tedious and expensive process to establish this appropriate line design solely based on experimental findings. Hence, the computational based numerical analysis with the support of final experimental validation aids in arriving at a safe and optimal transmission line design dimension configuration. Thus, the ionic current flow environment of UHVDC transmission lines may be characterized by ionized space charge density, ionic current flow, and electrical field distribution. To estimate this ionic current flow, it is necessary to estimate the ionized space charge density in the ionization region, which incorporates the solution of the Poisson's equation. It is intricate to solve Poisson's equation with known boundary conditions: as ionization process depends on the atmospheric parameters also. Multiple computational techniques are developed to estimate the corona generated ionic current environment under the HVDC lines by waiving these atmospheric parameter effects and claims the lack of computational accuracy. In this paper, the unipolar corona equation, usually called Poisson's equation was solved by estimating the space charge ion density using the concept of gas bimolecular collision theory. The gas bimolecular collision theory inculcates the procedure to estimate the collisional reaction rate constant between the gas molecules at given atmospheric temperature and pressure parameters. Therefore, this paper developed a unique equation solution for the estimation of transition of the ionic current magnitudes at known atmospheric temperature and pressure ambient conditions. This unique equation solution prevents the multiple actual testing procedures offers to obtain safe and optimal line design dimension configurations. Multiple experimental studies are carried out up to ± 900 kV to compare the computed results in the outdoor and indoor climatic conditions at the ultra-high voltage laboratory, CPRI. Also, the computed results are compared with the results published in the literature. Based on the comparison of results, the developed computational technique exactly matches the experimental results and claims improved accuracy compared to other computational techniques.

An indoor airflow distribution predictor using machine learning for a real-time healthy building monitoring system in the tropics

Indoor air quality is the foundation of a good indoor environment. The COVID-19 pandemic further highlighted the importance of providing real-time airflow distribution information within the Building Environmental Monitoring System (BEMS) to minimize the risk of infectious airborne transmission. This paper discusses the process of developing a predictive model for indoor airflow distribution prediction with indoor and outdoor input parameters using machine learning and its implementation in healthy BEMS for a classroom in the tropical climate region of Yogyakarta, Indonesia. This paper encompassed field measurement and simulation involving outdoor climate conditions and the operational status of the classroom’s windows, Air Conditioning units, and fans. Three machine learning models were constructed using OLS, LASSO, and Ridge methods. Datasets for the modeling were generated from CFD model simulations in IES VE and were assessed for correlation. The mean temperature and velocity differences between the CFD model simulation and measurement results are 0.21°C and 0.083 m/s, respectively. Outdoor climate conditions and the operational status of the classroom’s utilities significantly influence the indoor airflow distribution characteristics. The three models indicate a relatively poor performance, where the classroom had a relatively low sensitivity to input changes. However, the best model performance was achieved using the LASSO method, with average values from post-normalization of [Formula: see text] and Root Mean Square Error (RMSE) of 0.336 and 0.077, respectively. The model was implemented in healthy BEMS on the “Platform for Healthy and Energy Efficient Building Management System.” Practical Application: This research proposed a machine learning model of indoor airflow characteristics of a classroom in Yogyakarta. The proposed model can be adapted to produce monitoring systems that best represent the related conditions. The method can be adopted to develop a relatively simple, low-cost sensor or model to monitor an indoor environment. Future studies may explore the results of the real-world implementation in a case study.

Characterization of the Thermal Behavior of Semi-Exterior Laundry Spaces in an Overheating Passivhaus Residential Building in Bilbao, Spain

Overheating in buildings is a growing challenge in temperate climates, even in those where the traditional design focus was on protecting from cold and winter energy savings. This paper addresses a collateral problem that arose during the study of overheating in a residential Passivhaus building in Bilbao, northern Spain. Specifically, the local climate of three laundry spaces was investigated, where high daytime and nighttime temperatures were recorded. An extensive monitoring campaign was carried out with different durations up to more than 21,000 h over four years, and the collected data were compared with outdoor climatic conditions. The results allowed for characterizing the thermal behavior of these semi-outdoor spaces and show the magnitude of the problem, quantifying it. Laundry spaces were confirmed to be hotter and dryer than the outdoor climate almost always. The mean average difference between the monitored rooms and the exterior was quantified to be around positive 5 °C during both daytime and nighttime. Extreme heat events were documented, with maximum temperatures above 50 °C and temperature differentials of up to 15.85 °C. In addition, this article comments on the impact of overheating these laundry spaces on the interior of the dwellings, pointing out the differences between the assumptions made during the design phase of the project and the observed or measured reality. Questions were raised about the possible implications of the peculiar performance of these semi-outdoor spaces on the mechanical heat recovery ventilation system (MHRV). The data presented in this article revealed and quantified a design flaw that went unnoticed by all agents involved in the planning, design, and construction of the 361-apartment project. The inability to predict the behavior of the studied spaces has had a negative impact on building performance during the summer months and has prevented the implementation of strategies that could have been beneficial in other periods. A thorough analysis of the thermal behavior of similar spaces becomes essential to prevent performance gaps in future projects and to inform adequate building modeling in the design stages.

A neural network for monitoring and characterization of buildings

This paper continues work from part 1 where a high precision estimator for energy efficiency and indoor environment based on artificial neural networks (ANN) was examined. Part 1 demonstrated that creating a precise representation of a mathematical relationship one must evaluate the stability and fitness under randomly changing initial conditions. Now, we extend our requirements for the model to be rapid and precise. At the end of this work we obtain a road map for the design and evaluation of ANN-based estimators of the given performance aspect in a complex interacting environment. This paper also shows that ANN system designed may have a high precision in characterizing the response of the building exposed to variable outdoor climatic conditions. The absolute value of the relative errors, MaxAR, is less than 2%. It proves that monitoring and ANN-based characterization approach can be used for different buildings, including those with the best environmental performance.

Thermal Modeling of Photovoltaic Panel for Cell Temperature and Power Output Predictions under Outdoor Climatic Conditions of Jodhpur

The rise in the temperature severely affects photovoltaic cell efficiency and hence its power output. Moreover, it also causes the development of thermal stresses that may reduce their life span. Thus, there is a need for an accurate estimation of the cell’s working temperature. In this paper, a detailed thermal model based on various heat transfer modes involved and their governing equations has been presented to estimate the cell temperature of a PV module using MATLAB software under different climatic and solar insolation conditions. In order to validate the presented model, an experimental setup has been built and operated under actual outdoor conditions of Jodhpur, a city in the Thar Desert of Rajasthan. For the peak summer month of June, the predicted glass cover outer surface temperature has been found to be within 0.2–4.5°C of experimentally measured values and the back sheet temperature is found to be within 0.5–5.5°C. The predicted and measured power outputs have been found to be within 0.85–1.2 W while the efficiency values are within 0.17–0.38%. For the early summer month of April, the variations are 0.13–4.1°C, 0.2–4.1°C, 0.44–1.65 W, and 0.1–0.5% for glass cover temperature, back sheet temperature, power output, and efficiency, respectively. Thus, the predictions of the developed thermal model have exhibited a good agreement with the experimental results. The maximum glass cover temperatures recorded were 60°C and 65.5°C when the ambient temperatures were 35°C and 42°C near the noon for the early summer and peak summer day experiments, respectively. The presented model can be used to generate a year-round cell temperature data for the known environmental data of a location, which can help in the selection or development of appropriate cooling technology at the planning stage of the installation of a solar PV plant.

Sensitivity Analysis of Traditional Solid Masonry Wall to Frost Damage in North China

The historic façades are significant to building heritage, but they are also extremely vulnerable to changing environmental conditions. Water is well studied as the primary agent that causes the deterioration of porous materials, but the impact of variations in moisture storage, moisture transport, and thermal properties of the materials in solid masonry wall construction remains uncertain and requires quantitative analysis. Sensitivity analysis of solid wall construction can be beneficial in understanding the correlation between material properties and risk in proposing rational preservation strategies. This paper aims to investigate the predominant parameters for frost damage criteria in traditional Chinese masonry construction in North China. Under typical outdoor climate conditions in North China and a constant indoor climate, a 2D Heat, Air Moisture (HAM) model is applied to 240mm and 370 mm thick walls. The sensitivity analysis is quantified with three frost-related criteria. The hygrothermal simulation validates that the main dominant factor varies with different criteria and that the properties of adjacent materials dominate the frost damage risk at certain locations. The results could contribute to the expansion of the international material database and the conservation of masonry heritage from the risk of the freeze-thaw cycle.

Multi-scale analysis of the effects of hysteresis on the hydrothermal behaviour of bio-based materials: Application to hemp concrete

Experimental measurements of sorption isotherms show a difference between the water contents in the adsorption phase and the desorption one. This is mainly due to the hysteresis phenomenon. Not considering this phenomenon in hygrothermal behaviour models impacts the reliability of the latter. In this paper, we have studied the effects of hysteresis on the hygrothermal behaviour at the building scale. For this purpose, a new implementation method of a hysteresis model was proposed and validated at the material and wall scales using a bi-climatic chamber which controlled the indoor and outdoor climate conditions. Then, the effect of the hysteresis phenomenon at the building scale was evaluated following a COMSOL/TRNSYS co-simulation approach to consider the gains and losses in the hydric fluxes going through walls. The results showed significant differences in terms of the relative humidity of the living environment. However, no difference was noticed in the temperature variations. On the other hand, the total heat fluxes were also affected by the hysteresis phenomenon due to latent heat parts, that were driven by variations in relative humidity. The maximum gain and loss discrepancies (with and without hysteresis) in total heat fluxes of 1121 kJ/h and 1086 kJ/h, respectively, were obtained during the first week of February (winter period). The results also revealed that these discrepancies are sensitive to the number of persons in the living environment.

A day-ahead operation regulation method for solar water heating based on model predictive control

The operation performance of a solar heating system is largely influenced by the coupling of outdoor climate conditions and building energy operation patterns, and is characterized by strong randomness and large heating fluctuations, which makes the optimal control rules for solar heating systems in dynamic state. Although the traditional RBC(rule-based control), whose rules is preset, has a fast response speed, the fixed-rules are hardly to make the solar heating system in optimal state. Furthermore, solar heating systems is generally characterized by a large time delay in the heat transfer process. The control point lag occurs in the control signal of the dynamic control strategy. To address these issues, this paper proposes a model predictive control-based (MPC) control strategy for solar heating systems. The method uses seq2seq-LSTM to predict major operating parameters including ambient temperature, solar radiation, the load inside the building for the next 24 h and combines the heating system operation model to simulate and obtain the control signal at the next moment. The results showed that, compared with traditional control strategies including RBC and PID control strategies, the efficiency of solar collector regulated by MPC increased by 9%. Taken the tank temperature at the simulation end as the energy calculation reference point, the solar heating system’s total energy consumption employing MPC is 34.2% lower than that employing traditional control strategy.

Definition of thermal comfort of crops within naturally ventilated greenhouses

Controlling the microclimate condition inside a greenhouse is very important to ensure the best indoor conditions for both crop growth and crop production. To this regard, this paper provides the results of a novel approach to study a greenhouse, aiming to define a porous media model simulating the crop presence. As first, an experimental campaign has been carried out to evaluate air temperature and air velocity distributions in a naturally ventilated greenhouse with sweet pepper plants cultivated in pots. Then, the main aspects of energy balance, in terms of mass transfer and heat exchange, and both indoor and outdoor climate conditions have been combined to set up a computational fluid dynamics model. In the model, in order to simulate the crop presence and its effects, an isotropic porous medium following Darcy’s law has been defined based on the physical characteristics of the crops. The results show that the porous medium model could accurately simulate the heat and mass transfer between crops, air, and soil. Moreover, the adoption of this model helps to clarify the mechanism of thermal exchanges between crop and indoor microclimate and allows to assess in more realistic ways the microclimate conditions close to the crops.

Numerical investigation of sustainable thermal energy storage (TES) system for personal helmet cooling

The present work investigates the potential of PCM in a compact and portable TES, known as a PCM packet, to design a helmet for supplying cool air around the head and face. Two different PCMs, namely RT27 and Capric acid, have been chosen, and their performance comparison was evaluated using a developed numerical model. The present work analyzes the effect of PCM-packet orientation, melting temperature range, thermal storage capacity, and optimum configuration. The current model validates experimental results. The results reveal that the melting front propagation is sensitive to packet orientation, and at a particular instant, RT27 has shown a maximum liquid fraction compared to Capric acid. RT27 and Capric acid encapsulated systems held horizontally obtained melting times of 150 min and 175 min, respectively. The air outlet temperature was significantly reduced with the RT27 PCM-packet in the horizontal case since the air inlet boundary condition closely matches the PCM's melting temperature. Moreover, the designer can choose the orientation and design the PCM packet according to outdoor climate conditions.

Experimental investigation, modeling and in-situ monitoring of a gas-driven absorption heat pump in Belgium

This work describes the methodology used to realize a performance analysis of an ammonia-water condensing gas absorption heat pump. This heat pump shows a nominal heating output of 18,9 kW for an outdoor temperature of 7 °C and a delivery temperature of 35 °C, and it is designed for domestic hot water and heating production. The experimental results obtained in the laboratory are contrasted with those obtained from the monitoring of two residential facilities in the northern part of Belgium. Experimental tests were carried out in a climatic chamber to emulate different outdoor climatic conditions based on a combination of the EN 12309 requirements and typical Belgium weather data. Measurements of gas consumption, electrical consumption, water flows, and temperatures were collected to compute performance indicators. On the other hand, the monitoring data was analyzed and contrasted with the experimental results to evaluate the field systems’ performance; the problems found and modifications made are described and discussed. The results show that the performance of the systems is highly dependent on the coupling with other appliances, on the operating conditions and control of the system, resulting in penalties that can be considerable depending on the configuration used. An empirical model calibrated with experimental data is proposed, as well as a penalization factor calibrated with the monitoring data. The results presented evidence the differences found between the studied facilities, highlighting the main role of proper installation and control not to diminish the main performance indicators.

Natural cooling solution for thermally conditioning bus stops as urban climate shelters in hot areas: Experimental proof of concept

In response to the challenges posed by climate change and the growing heat patterns in cities, this study addresses the design and implementation of climate shelters integrated into public transport stops through the installation of surface radiant cooling modules. The aim is to improve the thermal comfort of short-stay users in cities in hot, dry climates. To this end, a fully sensorized thermal camera was used in a controlled setting to simulate real outdoor climate conditions and evaluate the efficacy of the radiant system. The prototype was modelled and characterized by means of in situ measurements, paying special attention to the temperature and radiant heat flux. The radiant modules maintained a temperature between 18 °C and 20 °C, even under oppressive conditions, with over 50% of the cooling flux due to radiation. The radiative performance of the prototype did not increase proportionally with increased water flow, stabilizing at high flows. The analysis of the thermal comfort index showed a decrease in feelings of discomfort of between 40% and 50% when the modules reached the set point temperature. The study shows that implementing these climate shelters in public transport stops such a bus shelters is feasible in hot, dry climates. This may be an effective strategy for mitigating the effects of climate change in urban areas and can be applied in any city that suffers from recurring heatwaves, thereby improving living conditions for city goers.

Analysis of the Influence of Office Building Operating Characteristics on Carbon Emissions in Cold Regions

Reducing buildings’ operational carbon dioxide emissions has become a crucial element in China’s efforts to achieve carbon peak and carbon neutrality targets. This study focus on the influence of office building operating characteristics on carbon emissions in cold regions. By utilizing DesignBuilder v7.0.0.096 to conduct numerical simulations of 10 different operating conditions for heating, ventilation and air-conditioning (HVAC) and lighting systems, this study solves the problems in the past of poor comfort and high energy consumption with manual management and achieves a win-win situation for health and environmental protection. The study shows that by implementing a mixed mode of mechanical ventilation and natural ventilation based on outdoor climate conditions and design requirements, unsatisfied hours can be reduced by 202 h compared to the traditional air condition heating operation mode for both winter and summer seasons. Furthermore, compared to a year-round HVAC operation mode, the air-conditioning energy consumption can be reduced by 19%, resulting in a carbon emissions reduction of 1.45 kg CO2/(m2·a). Additionally, for every 2 °C increase in the outdoor temperature, the cooling energy consumption decreases by 2–5%. In terms of lighting, the intelligent lighting mode can reduce energy consumption by 31.04%, leading to a carbon emissions reduction of 3.04 kg CO2/(m2·a). The coupling operation characteristics of mixed mode, intelligent lighting, and energy-saving lamps can achieve a maximum saving of 83.46 MWh of electricity and approximately CNY 72,000 every year, with a static payback period of approximately 2.7 years. This operational strategy, which fully considers the utilization of natural ventilation and daylighting in conjunction with traditional design approaches, improves indoor air quality and ventilation conditions, while also maximizing the energy-saving and carbon reduction potential. The study results provide valuable design and operational guidance for new and existing office buildings in cold regions, to effectively reduce carbon emissions, while offering significant investment returns.