Hot Climate Zones Research Articles

A multi-factor optimization method based on thermal comfort for building energy performance with natural ventilation

Natural ventilation is one of the most potential passive measures to improve the building energy performance. This study introduces a multi-factor optimization method for energy performance of buildings with natural ventilation. To maximize the utilization of natural ventilation, this method uses natural-ventilation strategy (Strategy NV) as the air conditioning system operation strategy. In Strategy NV, the air conditioning system is only on when the natural ventilation cannot fulfill the occupants’ thermal needs. Two thermal comfort models and airflow network model are combined to obtain Strategy NV. Support vector regression is applied to train a surrogate model which is used to predict the annual energy consumption in Strategy NV. Introducing the surrogate model as objective function, particle swarm optimization is used to find the optimal solution. A case study in hot summer and cold winter climate zone is given to verify the feasibility and correctness of this method. The optimal solution has 656 GJ annual energy consumption in Strategy NV, including 254 GJ annual thermal energy consumption. The optimal solution saves annual thermal energy consumption by 21% in Strategy NV comparing with Strategy FT (full time operation strategy within occupied period). The annual thermal energy consumption of the optimal solution in Strategy NV is at least 26% smaller than that of four commonly used building designs in Strategy NV; and it is at least 43% smaller than that of the four commonly used building designs in Strategy FT. The optimal solution has the least total air conditioning hours comparing with the four commonly used building designs.

Long-term carbon intensity reduction potential of K-12 school buildings in the United States

School buildings have a great potential for carbon emission reduction since their annual emission is about 72 million metric tons. Currently, more than 30 % of school buildings were built before 1960 and are underperforming. To effectively reduce carbon emissions via school building retrofits, it is critical for policymakers to understand the carbon intensity reduction potential of retrofitting school buildings in different regions. Hence, this study develops a method to comprehensively assess the long-term carbon intensity reduction potential of aggregated commercial buildings on a county-by-county basis in the continental U.S. We apply this method to the K-12 school buildings including primary and secondary school buildings. This paper predicts the carbon intensity reduction potential of K-12 school buildings with eight building retrofit measures from 2022 to 2050 in the continental U.S. The results reveal several interesting findings: (1) In the approximately 3,000 counties of the U.S. from 2022 to 2050, the carbon intensity reduction potential of retrofitting K-12 school buildings in each county ranges from 0.41 kg/m2 to 40.00 kg/m2. (2) Even in the same climate zone, the trends of carbon intensity reduction potential from 2022 to 2050 are different depending on their electricity sources. For example, in a hot and humid climate zone, the carbon intensity reduction potential in Florida will decrease from 2044 to 2048. However, in Mississippi, the carbon intensity reduction potential from 2044 to 2046 will increase due to the termination of the nuclear energy usage. (3) Generally, reducing lighting power density leads to more carbon intensity reduction in most states, but it might not be applicable for states with high clean energy penetration, such as Washington.

Use of TEVY index to measure the temperature variability within a year in different climatic zones of Nepal

TEVY index has been proposed and used to evaluate the temperature variability in 4 stations in Greece. In order to establish the index, more study is necessary; so, this work is aimed to apply TEVY index across 9 stations in Nepal. Daily mean temperature is calculated for each station from the historical data of up to 44 years. Fourier Harmonic analysis is carried out to estimate the daily temperature. Then TEVY index is calculated as the squared of the difference between observed temperature and Fourier series estimated temperature. Correlation analysis carried out to check the level of fit between observed and estimated temperature values. The TEVY index shows the higher variability of temperature in hot climatic zone followed by mild climatic zone and cool climatic zone. Monthly TEVY value shows the higher variation in temperature, that coincides with the precipitation cycle of Nepal, but this statement requires more study to check its validity.

An analysis of degradation in low-cost particulate matter sensors.

Low-cost sensors (LCS) are increasingly being used to measure fine particulate matter (PM2.5) concentrations in cities around the world. One of the most commonly deployed LCS is the PurpleAir with ~ 15,000 sensors deployed in the United States, alone. PurpleAir measurements are widely used by the public to evaluate PM2.5 levels in their neighborhoods. PurpleAir measurements are also increasingly being integrated into models by researchers to develop large-scale estimates of PM2.5. However, the change in sensor performance over time has not been well studied. It is important to understand the lifespan of these sensors to determine when they should be serviced or replaced, and when measurements from these devices should or should not be used for various applications. This paper fills this gap by leveraging the fact that: (1) Each PurpleAir sensor is comprised of two identical sensors and the divergence between their measurements can be observed, and (2) There are numerous PurpleAir sensors within 50 meters of regulatory monitors allowing for the comparison of measurements between these instruments. We propose empirically derived degradation outcomes for the PurpleAir sensors and evaluate how these outcomes change over time. On average, we find that the number of 'flagged' measurements, where the two sensors within each PurpleAir sensor disagree, increases with time to ~ 4% after 4 years of operation. Approximately 2 percent of all PurpleAir sensors were permanently degraded. The largest fraction of permanently degraded PurpleAir sensors appeared to be in the hot and humid climate zone, suggesting that sensors in these locations may need to be replaced more frequently. We also find that the bias of PurpleAir sensors, or the difference between corrected PM2.5 levels and the corresponding reference measurements, changed over time by -0.12 μg/m3(95% CI: -0.13 μg/m3, -0.10 μg/m3) per year. The average bias increases dramatically after 3.5 years. Further, climate zone is a significant modifier of the association between degradation outcomes and time.

Evaluating Spatial Identity Based on Climate Adaptation in Small Cities.

Urban spatial identity is declining in Chinese cities overall due to urbanization, which is attracting increasing attention from the government. Research gaps include systematically comparing urban identities based on causes and manifestations in small cities. We developed a framework for estimating spatial identity from the perspective of climate adaptation, which is based on the relationship between regional climate and spatial form. Five small cities were selected in China: Wu'an, Qingcheng, Jintang, Changxing, and Lianjiang. Our findings suggest that (1) typical indicators include impervious surface rate, green coverage rate, water surface rate, average story number, and total gross floor area, contributing to morphological characteristics influenced by climate drivers; (2) for the hot humid climate zones, the city with the highest level of spatial identity is in Jintang, followed by Lianjiang and Changxing; and for the cold climate zones, the level of spatial identity in Qingcheng was higher than in Wu'an. This can contribute to the understanding and methodology of spatial identity based on climate adaptation in small cities.

Performance evaluation of ventilative cooling systems for buildings under different control parameters and strategies

Ventilative cooling is an energy-saving technology to diminish thermal discomfort and overheating risk of buildings, meanwhile achieving high indoor air quality (IAQ). However, there is still no optimal control strategy in practice, which considerably limits its application. This study developed a typical office building model to evaluate the performance of ventilative cooling systems with different control parameters and strategies for five typical cities in different climatic zones of China. Results showed that, when the control parameter was selected as the upper limit of satisfied comfortable zone by 90% of the occupants, the adaptive thermal comfort (ATC) model, which outperformed the other models in terms of outdoor air utilization, was not necessarily optimal in terms of energy efficiency. The outdoor air utilization potential based on the indoor dry-bulb air temperature (Td) and indoor operative temperature (Top) control was similar, but the energy usage varies considerably, especially in the hot climatic zones. When the overheating period controlled based on the thermal comfort models was the same, the energy usage would be underestimated by 16%–38% without considering the effect of radiant temperature. The ATC-based control could have up to 37% of energy-saving compared to thermostatic control, but inappropriately low limits could make it less advantages to achieve energy-saving. The energy-saving potential associated with the PMV and ATC controls showed a completely opposite trend in the different climatic zones. The analysis results indicate that eliminating the drawbacks of the lower limit in the ATC model is an effective way to demonstrate energy-saving effectiveness. The findings of this study will contribute to the effective improvement of the application potential of ventilative cooling in different climatic zones.

Impact of Location and Insulation Material on Energy Performance of Residential Buildings as per Saudi Building Code (SBC) 601/602 in Saudi Arabia

In hot and humid climates, a significant part of the energy is used to cool the building. There are several ways to reduce this air conditioning load, but one standout is through the selection and design of the right building envelope and its components. The thermal characteristics of the building envelope, in particular the thermal resistance of the insulation used, have an impact on the thermal and energy performance of building structures. Thermal conductivity, which indicates the ability of heat to move through a material given a temperature difference, is the primary factor affecting the performance of a thermal insulation material. Both temperature and humidity changes can affect a material's thermal conductivity value, which can then change. In fact, due to the fluctuating ambient air temperature and solar radiation, thermal insulation in buildings is susceptible to significant and continuous temperature variations. Thermal insulation used in building walls and roofs helps to reduce the energy demand of the building. It improves thermal comfort and, if used correctly, reduces the operational cost of the building. The present study has focused on the effects of location and insulation material on the energy performance of a residential building by considering five climatic locations in the Kingdom of Saudi Arabia (KSA). Five commonly used insulation materials with different thermal characteristics, namely polyurethane board (PU), expanded polystyrene (EPS), glass wool (GW), urea-formaldehyde foam (UFF), and expanded perlite (EP), were analyzed under various climatic zones as per the Saudi Building Code 601/602. The selected cities were categorized based on cooling degree days (CDD) and outdoor dry bulb temperature (DBT) as hot, very hot, and extremely hot climatic zones. Insulation improves thermal comfort and, if used correctly, reduces running costs. Experiments were conducted to determine the thermal conductivity, and the energy simulation was performed by employing IES-VE software for various insulation options. The findings indicate that the location has a significant impact on the energy performance of the insulating materials. The energy saving potential of polyurethane board (PU) insulation is more attractive in cities with higher DBTs and CDDs than in cities with lower DBTs and CDDs. The benefit of installing insulation ranged from a 2 to 14% decrease in energy demand for the climate zones studied. The sensitivity analysis showed that the energy saving potential of the insulation materials is sensitive to the set-point temperature (ST) band.

ANALYSIS OF SEASONAL AND ANNUAL VARIATIONS OF EXTREME TEMPERATURES AND PRECIPITATION IN ETHIOPIA

One of the most serious challenges in the world is climate change. This study examines variations in seasonal and yearly fluctuations in extreme temperatures and precipitation in Ethiopia from 1987 to 2020 using 36 meteorological stations located in various climatic zones. The outcomes of the study demonstrated increased trends in the average annual maximum and minimum temperatures, with values of 0.094∘C and 0.052∘C, respectively. Despite falling trends in the summer, most stations experienced higher winter temperatures than summer. Furthermore, the analysis revealed a trend toward an increase in the number of rain stations over the summer season, while a trend toward a decrease in the amount of precipitation for a number of stations in the winter season; otherwise, large changes expected in the dega (cold), woina dega (cool), and kola (warm) climatic zones during the summer season did not occur. Precipitation activity has been near normal in most dega (cold), woina dega (cool), and kola (warm) climatic zones over the preceding 33 years. However, precipitation in the berha (hot) climatic zone was lower than average, with fluctuating levels noted throughout the year. The average annual precipitation has been decreasing at a rate of 0.146[Formula: see text]mm per year over the past 33 years, indicating that only the winter season has shown a downward (decreasing) trend, while the other three seasons, such as summer, spring, and autumn, have shown growing trends. Furthermore, Ethiopia’s average annual rainfall continues to be on a downward trend (decreasing).

Climate adaptation of design scheme for energy-conserving high-rise buildings—Comparative study of achieving building sustainability in different climate scenarios

Given the climate-sensitive interactions between buildings and the immediate environment, an insight into the impact of design parameters on building energy performance under specific climate environments is crucial for the sustainable development of green buildings. The following study imparts a distinctive view of the performance-based effect of architectural and engineering design parameters on high-rise office buildings by exploiting the advantages of climatic features in different climate environments. Therewith, the study identifies and compares the major sensitive design parameters on the energy performance of high-rise buildings in different climate contexts. Furthermore, the most applicable passive strategies to attaining stipulated building sustainability criteria are established. The results indicate that the energy performance in a certain climate environment is highly sensitive to the design characteristics, such as plan ratio, core position and atrium effect. In a cold climate environment, a high-rise building with a rectangular building plan (plan ratio = 1:1.44, with vertical split-core in the absence of an atrium), satisfies the Passivhaus engineering criteria on air-tightness and fabric insulation; and adopts double-glass curtain walls, presented the best energy performance. Whereas, a square building plan (with vertical split-core and no atrium) that complies with the air-tightness and fabric insulation criteria under Passivhaus engineering standards, minimizes east- and west-bound window exposures, and adopts double-glass curtain walls exhibited the best energy performance in the hot climate zone. However, it requires renewable energy systems as an additional energy source to attain the stipulated building sustainability criteria.

Impact of placement and design of phase change materials in thermally activated buildings

Phase change materials (PCMs) and thermally activated building systems (TABSs) are two candidate technologies for reducing the energy consumption of modern buildings due to their favorable thermal storage features. However, the existing relevant studies do not specify the optimal integration schemes of PCMs when used in radiant cooling systems. Hence, this paper reports the first attempt to parametrically optimize the PCM-TABS system integration, considering typical open office space in the hot and dry climate zone of Cairo, Egypt. Using dynamic system simulations, four system configurations are examined, regarding the relative positions of the activated slab and Bio-PCM layer (ceiling or floor), and compared to active ceiling or floor systems (without PCMs). The results demonstrate the feasibility and favorableness of using PCMs in TABS, with energy and cost saving up to 18.80 and 19.78 %, respectively. The largest cost savings are achieved when PCMs are incorporated into the radiant ceiling, with a melting temperature of 22.0 °C and thickness of 6.0 cm. Energy savings also increase as the volume of PCMs increases, with melting temperatures closer to the building's setpoint. The percentage of comfortable hours decreases slightly from ~100 % to >95.5 % when using some PCM designs due to their thermal inertia, but PCMs result in generally lower variations of indoor thermal comfort. By mapping the performance of such system configurations, the study can be valuable for researchers and practitioners alike to determine the optimal integration scheme of PCMs in radiant cooling systems.

Preferable and limiting conditions of trans-Palearctic <em>Orthocephalus</em> species (Heteroptera: Miridae)

The environmental conditions limiting the distribution of trans-Palearctic species from various groups remain poorly studied. This work addresses the topic from three perspectives: (1) analysis of climatic variables, biomes and climate zones corresponding to the actual records; (2) assessment of environmental niches and contribution of biomes to those niches; (3) comparison of the distributional limits of trans-Palearctic and more local species. The genus Orthocephalus (Insecta: Heteroptera: Miridae) is used as a model taxon. The results have demonstrated that all trans-Palearctic species of this genus are known from numerous biomes and climate zones, but each of them has unique preferences. Biomes significantly contribute to the environmental niches of some of those species. None of the trans-Palearctic species were recorded from the hot steppe and desert climate zones, which occupy large areas in the Palearctic, although certain rare and local species inhabit those regions. This means that the trans-Palearctic species cannot easily adapt to those conditions.

Evaluation of Daylight and Glare Quality of Office Spaces with Flat and Dynamic Shading System Facades in Hot Arid Climate

There has been an increasing awareness in recent years about the evaluation of daylight and glare quality in buildings. In the study, an office space with a flat and a dynamic shading system facade (triangular cell facade) is discussed in the province of Mardin, which is in a hot and arid climate zone. Observing two different facade types in a single office space allows the study to be carried out in detail, and their suitability can be checked by producing quick design alternatives. The analysis and evaluation of daylight and glare quality over office spaces with two different facade types aims to develop an innovative approach. This objective is designed to respond to climatic conditions and contribute to the development of climate-sensitive designs. The study was parametrically simulated with the Grasshopper plugin and daylight plugin ClimateStudio tools in Rhino, an office space with both a flat facade and a dynamic shading system facade located in a hot-arid climate. As a result of the analysis, the dynamic shading system, which can transform according to the position of the sun, shows outputs in accordance with the LEEDv4 standard, minimizing the ASE value of the facade's annual sunlight exposure by up to 10%, while maximizing the spatial daylight autonomy sDA value by 60% or more. In addition, Daylight Glare Probability (DGP) values of 0.38 keep the visual quality affective. As a result, the office space with a dynamic shading system facade showed that it can significantly improve the flexibility of shading to control daylight measurements and glare, achieving the maximum level of visual comfort based on the LEEDv4 certificate.

Identifying relative importance of solar design determinants on office building façade for cooling loads and thermal comfort in hot-humid climates

Solar radiation makes great influence on cooling load and occupants’ well-being in hot and humid climate zone. Particularly, occupants suffered different extent of solar radiation owing to their positions; thus, assessing the spatial and temporal thermal comfort is essential. It is worthwhile to identify the relative importance of passive solar design parameters for building envelope that these parameters directly affect thermal comfort and energy use. This study confirmed the distribution frequency of cooling loads and temporal thermal comfort usability of the simulation cases in selected cities based on the MRT algorithm that considered the impact of solar radiation. Based on the results, sensitivity analysis was used to analyze the relative importance of passive solar design parameters to clarify the priority when drawing up the façade design strategies. Eventually, correlation among facade parameters, energy use, thermal comfort, and geographic location is revealed. Furthermore, the improvement potential for energy-saving and thermal comfort by adjusting the variables in specific ranges is also demonstrated. The results indicated that within all selected cities, adjusting glazing type makes greatest influence on improvement potential that ranges from 22.8% to 39.5% in annual cooling load and 58.6%–87.5% in temporal thermal comfort usability, whereas the improvement potential for orientation is weaker than other parameters. Moreover, the absolute effect of solar design determinants is also disclosed respectively to discuss the importance of each parameter. Comprehensively, the proposed findings are expected to act as instruction when formulating the passive building envelope design related to solar radiation.

Energy analysis of a phase change material embedded heat exchanger for air conditioning load reduction in different Indian climatic zones

Air conditioning (AC) systems for tropical countries like India account for sixty percent of the total energy needs of a building. With the onset of COVID-19, the increase of fresh air ventilation rate has been recommended by various guidelines for indoor spaces which increase the load on the AC system. The present study attempts to reduce this burden through retrofitting a phase change material (PCM) embedded pin fin heat exchanger into an air-conditioning system. The heat exchanger is designed to cater to the peak load fluctuations for cities in three hot climatic zones of India, viz., Jaisalmer, Kolkata, and Delhi. Dodecanol with a melting temperature of 24 °C, is chosen as the appropriate PCM material for these locations. The optimal pin fin diameters are estimated through an entropy generation minimization analysis for the three locations. A heat transfer analysis of the PCM embedded heat exchanger is further presented through an analytical approach to estimate the PCM mass requirement and energy savings potential. The masses of the PCM estimated for Jaisalmer, Kolkata, and Delhi are 11.36 kg, 22.42 kg, and 19.35 kg, respectively for their respective peak load fluctuations of 0.25 kW, 0.28 kW and 0.48 kW. Energy savings of up to 4.7 % for Delhi, 2 % for Kolkata, and 2.75 % for Jaisalmer are identified with the PCM embedded heat exchanger incorporation. The results show the potential of such PCM thermal storage in reducing the peak energy demands of buildings amidst various environmental and health concerns.

Investigating passive strategies in a cold climate – teaching EDDA in architectural education

This paper describes the results of an architectural teaching module investigating passive building strategies in cold climatic conditions on the case study of Iceland. Focusing on thermal comfort in buildings, usual case study tasks are located in cooling-dominated climates - as vernacular design for hot climate zones offers more passive strategies than for cold climates. As part of the architectural education programme at Jade University of Applied Sciences, students investigated the impact of passive strategies in a building design concept for a hotel in Iceland by applying numerical simulation within the initial design phase. The aim was to develop a holistic energy efficiency strategy and to optimize their initial design propositions exploiting its full potential for high thermal comfort in the guest rooms. Although each student started with an individual research question for a specific passive strategy, i.e., investigating varying construction materials, buffer zones, window-wall-ratio, Trombe walls, etc., all design concepts finally included multi-storey glazed buffer zones contributing to comfortable room temperatures by high solar gains from April to September resulting in a significantly reduced heating load. Furthermore, the study identified several design metrics for passive solar buffer zones to ensure the positive impact throughout the months with varying solar intensity. The teaching module called EDDA (Environmental Digital Design Analysis) is based on simplified 3D models in McNeels Rhinoceros 3D undergoing thermal simulation with a Grasshopper–Ladybug-Honeybee workflow. This allowed the students to iterate their building designs for maximum thermal comfort before adding HVAC systems. Ultimately, EDDA fostered to design climate-sensitive buildings by identifying a suitable set of passive strategies for the predominant climatic conditions as a first – but essential - step towards climate-neutral buildings. At the same time, prospective architects are empowered leading the building sectors towards a carbon-neutral future.

Multi-objective optimization of energy, visual, and thermal performance for building envelopes in China's hot summer and cold winter climate zone

The building envelope design parameters including windows, apertures, shading, and materials have a significant interactive impact on the performance of a building. However, few studies simultaneously optimize these parameters to determine the trade-off solutions between energy consumption, indoor daylighting, and thermal comfort. This study presents a multi-objective optimization (MOO) framework evaluating Useful Daylight Illuminance (UDI), Energy Use Intensity (EUI), and Thermal Discomfort time Percentage (TDP) with a wide range of parameters to investigate the interactive relationships between multiple building design and performance parameters. The openable-window-area-ratio (OWR), window-wall-ratio (WWR), solar-heat-gain-coefficient (SHGC), louver depth, and wall thickness are integrated into the optimization process. Taking a building in the Hot Summer and Cold Winter Zone as an example, the results show that a large south-openable-window-area-ratio (OWRs), south-window-to-wall-ratio (WWRs), SHGC, and wall-thickness with a small north-window-wall-ratio (WWRn) and louver depth are most suitable for improving energy performance without sacrificing thermal and visual comfort. The trade-off solution represents noticeable improvements by 18%, 48.4%, and 2.5%, respectively, compared with the initial solution in EUI, TDP for the transition seasons, and UDI. The outcomes help the architects to obtain an optimal solution for the design, refurbishment, and renovation of building envelopes in the HSCW zone towards the construction of sustainable cities.

Improving Cooling Capacity of Condensation-Free Radiant Cooling for Low-Emissivity Chilled Ceiling via Adaptive Double-Skin Infrared Membranes

Radiant cooling has well been acknowledged as energy efficient and thermal comfortable technology compared to conventional convective cooling. However, the radiant cooling exists two serious problems (viz., insufficient cooling capacity and high condensation risk) especially in hot and humid climate zones. By adding double-skin infrared transparent membranes (DIMs) onto radiant cooling panel, the air-contact surface can be separated from the cooling source surface, which makes it possible to use a low-temperature cooling source while maintaining air-contact surface higher than dew point temperature. The DIMs are transparent to radiant heat transfer which yields great cooling capacity while chilled ceiling has high emissivity (e.g., above 0.9). However, for metal chilled ceilings having low emissivity, radiant heat from cooling load to chilled ceiling would be reduced through DIMs, which results in insufficient cooling capacity. In this paper, a type of adaptive double-skin infrared membranes (a-DIMs) consisting a high-emissivity membrane and a high transparent membrane is proposed to improve cooling capacity of conventional metal chilled ceilings. The high-emissivity membrane serves as radiant cooling surface instead of low-emissivity chilled ceiling so as to improve radiant heat flux, while the high transparent membrane permits great radiant heat from cooling load to chilled ceiling. A combined heat transfer analysis based on semi-transparent surface radiation and natural convection were carried out to predict cooling capacity of condensation-free radiant cooling. The results indicate that the cooling capacity could be up to 101.9W/㎡ by adding a-DIMs consisting of a high-emissivity membrane of 0.96 and a high transparent membrane of 0.87, which is improved by 2 times compared to conventional metal chilled ceiling with low emissivity of 0.2. Moreover, the cooling capacity by adding a-DIMs is further improved by 25% compared to that by using both infrared transparent DIMs presented in our previous work. The results also indicate that the cooling capacity could be improved by above 2 times compared to conventional low-emissivity metal chilled ceiling by using the radiant cooling with a-DIMs for various humidity. It will be of great guidance for high-performance radiant cooling design without condensation and improved cooling capacity for low-emissivity metal chilled ceiling.

Impact of shading systems with various type-number configuration combinations on energy consumption in traditional dwelling (China)

In summer hot and winter cold climate zones, building energy behavior includes space cooling and space heating, resulting in confliction for determination of shading system. The building energy consumption assessments in this work were performed for the typical Chinese courtyard buildings situated in Sizhai Village. Taking into account the combinations of different types of shading device (3 types, i.e., overhang, buildings around the courtyard and gird slats), and variables of shading configuration (the depths of overhang, dimensions of courtyard and widths of grid salt were all assigned with 3 given variables), as well as building azimuths (4 categories, i.e., building azimuth intervals of south, north, east and west), a total of 252 (3 × 3 × 4 + 3 × 3 × 3 × 4 + 3 × 3 × 3 × 4) simulation runs were conducted. In consideration of the Sizhai's climatic features, the strategy of shading system with two-three configurations combinations (including 27 test scenarios) was proposed, which is more beneficial to improve of the building energy saving potential. The research results show that the test scenario with the shading system of B1O3–B1O3G3 combination has the maximum energy saving potential, contributing to the energy saving rates of 3%, 2.6%, 1.7% and 1.4% for the south-facing, west-facing, east-facing and north-facing dwellings, respectively.

Impact of Different Morphological Characteristics of Residential Areas on Wind Movement: Case Study of Karşıyaka (Izmir)

Cities are warmer than their surrounding rural areas due to the urban heat island effect. The heat island effect occurs in urbanized areas in which structures such as buildings and roads are highly concentrated and green cover is limited. Extreme heat waves resulting from climate change also cause temperature increases in the urban environment. In addition, the urban heat island effect negatively affects the comfort of individuals living in cities and increases the amount of energy required for cooling, especially in warm climate regions. To reduce both the urban heat island effect and the need for cooling, it is necessary to consider wind movement during the urban planning process. Within this context, it is vital that spatial development decisions allow planned building groups to benefit from natural ventilation opportunities. The morphological features of buildings directly affect the available opportunities to use wind energy for passive cooling in urban areas. Therefore, it is necessary to determine which morphological parameters affect the building-wind relationship. This study presents an analysis of wind simulations made by modeling selected examples of actual residential areas to determine the effects of different morphological features on wind movement. Twelve residential areas located in the Karşıyaka District of İzmir Province were determined for analysis due to their distinct morphological characteristics. The results of the study revealed that the parameters that affect wind movement in urban areas are the array of the buildings, their density, the distances between them, their floor area ratio, and their height. With regard to the provision of wind movement, it was found that the detached housing type is the most advantageous for hot climate zones. In addition, increasing the distances between structures was found to have a positive effect on natural ventilation. However, when viewed at the scale of residential areas, building heights on wind movements in the residential areas depends on the other two parameters. The simulations created for this study show that all morphological features of the building group under analysis affect wind movement, both separately and in combination.

A three-stage decision-making process for cost-effective passive solutions in office buildings in the hot summer and cold winter zone in China

China, with the largest energy consumption system in the world, faces numerous challenges in achieving the government’s commitment to reach a carbon-peak and carbon–neutral target. As the most common public building type in terms of floor area, office buildings have great potential for energy saving and emissions reduction. To meet this target, building designers target passive solutions that can meet the thermal comfort needs of occupants and also reduce energy consumption. This study aims to develop a decision-making method to select optimal solutions from among tens of thousands of design options considering the factors of energy consumption, comfort, and cost. We developed a novel optimization decision approach with the above-mentioned three objectives. The model consists of three stages: 1) the establishment of the reference building model, 2) sensitivity analysis to identify the main influencing variables and 3) the establishment of the optimization and decision-making model by applying NSGA-II and TOPSIS methods. By applying this three-stage decision-making model, this paper first proposes cost-effective passive design solutions for office buildings throughout the Hot Summer and Cold Winter climate zone. Finally, an office building in Shanghai was chosen as a case study to demonstrate the practical implementation of the proposed solutions through a post-occupancy evaluation with a two-year energy auditing and thermal comfort survey. It is evident that the proposed solutions provide support for the new low energy building design guide for office buildings along with necessary revisions to the existing standards for the Hot Summer and Cold Winter climate zone in China.