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Winter cold wave adaptation strategies in hot climates due to climate change didn't receive the deserved attention from previous studies. Therefore, this study comprehensively investigates the impact of various windbreak parameters on mitigating winter cold stress in hot steppe-arid climate. A microclimate model for a residential campus was built and validated through on-site measurement on a typical winter day to assess thirty-two scenarios for tree characteristics and spatial configuration windbreak parameters based on PET, wind speed, and Air Temperature (AT). Moreover, four configurations, that had best results on mitigating cold stress in winter, were tested during typical summer conditions to couple the assessment of cold and hot seasons. Additionally, environmental analysis for all scenarios was conducted. The results revealed that the most effective parameters for mitigating cold stress are tree distribution, Leaf Area Density (LAD), row number, spacing, and shape. Double rows of high LAD and medium height trees with small spacing yielded the best cold stress mitigation effect. Furthermore, the windbreak reduced the cold stress in the morning and night by 19.31% and 18.06%, respectively. It reduced AT and wind speed at night by 0.79 °C and 2.56 m/s, respectively. During summer, very hot PET area was reduced by 21.79% and 19.5% at 12:00 and 15:00, respectively. [ABSTRACT FROM AUTHOR]

This paper focuses on clarifying the heat transfer coefficient necessary for determining the indoor temperature distribution during night ventilation using floor-level windows. Measurements were used to identify the factors that influence the vertical temperature distribution within a room wherein phase-change materials (PCMs) were installed at the floor level. The investigation revealed a temperature differential ranging from 1 °C to a maximum of 3 °C between the floor and the center of the room, attributable to external climatic conditions (outdoor temperature and wind speed). This variation was found to depend on the degree of mixing of indoor air currents. This deviation was critical because it significantly affected the phase-change temperature of PCMs, thereby impacting their thermal storage capabilities. Consequently, this study aimed to refine the predictive accuracy of indoor temperature distributions by proposing a modified vertical temperature distribution model that incorporated these findings. The results of this study are expected to provide better design strategies for building constructions that incorporate PCMs, and to optimize their functionality in passive cooling systems. [ABSTRACT FROM AUTHOR]

Optimizing the thermal environment of a bedroom is desirable for good sleep. In moderate climatic conditions, natural ventilation is a viable method for enhancing the quality of sleep by improving indoor air conditions. This study examined the effects of air temperature and wind speed on sleep quality in naturally ventilated rooms with windows open and closed, during autumn. Thirteen young males in healthy conditions participated in this study. Two adjacent test rooms (for opened and closed conditions) were selected on a university campus, with standardized indoor conditions. Air temperature and wind speed were measured near the height of the participants' heads. Sleep efficiency and wake after sleep onset (WASO) were calculated using physiological wearable sensors based on heart rate and body movement. The participants completed questionnaires on thermal sensation and comfort before and after sleep. The results showed that the lowest percentage of WASO was observed when the nocturnal mean temperature was 23–24°C with a quadratic regression curve regardless of the window opening conditions. Conversely, subjective sleep satisfaction and WASO did not show any significant differences between the conditions. The results revealed no significant impact of varying thermal and airflow conditions during autumn on thermal/airflow comfort, although significant differences were observed in the thermal/airflow sensation before and after sleep. Thus, these results suggest that natural ventilation through the opening of windows might not affect thermal/airflow comfort, while a nocturnal indoor air temperature of 23–24°C is recommended for good sleep and thermal comfort, regardless of window opening conditions under moderate climate conditions. [ABSTRACT FROM AUTHOR]

We propose a multipoint measurement method for air temperature in outdoor spaces using polyvinyl chloride pipes with fan-aspirated ventilation. The method is applied to microclimate measurement in the outdoor space of a residential house, and the cooling effects of plants and natural ventilation on the house were evaluated. The accuracy of the proposed method was verified in the outdoor space. Average systematic errors of the method were 0.43 °C during daytime on sunny days and 0.16 °C on cloudy days. Application of the method to microclimate measurement shows that air temperatures were reduced by evapotranspiration of plants and watering in the planted space during daytime. By placing the plants near a floor-level window, wind speed inside the window was reduced, although the cooled air flowed into the indoor space through the window. The cooling effects of the plants and watering in the outdoor space kept indoor air temperature cooler during daytime. The period in which the sensible heat flux from the outdoor to indoor space showed positive values, i.e., when there was a sensible heat load in the room, diminished from 9 to 4 h through the cooling effects. [ABSTRACT FROM AUTHOR]

Air temperature is an important physical indicator of a built space. A novel method for remotely measuring the air temperature distribution using a thermal infrared spectroradiometer is evaluated, and an experiment using the maximum a posteriori method, which uses a priori information, is conducted with a heat source. The a priori information is the probabilistic information that the observer knows about the air temperature prior to the observation. Assuming an indoor scale (10 m), the air temperature distribution is estimated (i.e., retrieved) by discretizing the space into four layers. Accordingly, our method reduces the error in the air temperature estimation compared to the a priori information. When the layer of the heat source is known, the air temperature estimation is sensitive to the air temperature of the heated layer, even when the heat source is away from the sensor (2nd to 4th layers). The root-mean-square error (RMSE) of the heated layer decreased from 10 K (a priori) to 4.8 K. Although the RMSE of the temperature distribution was approximately the same regardless of the number of spectral channels used in the retrieval, the RMSE of the heated layer was smaller when ten spectral channels were used. In the case of a target space and spectrometer, as in this study, ten spectral channels were sufficient. These findings indicate the possibility of remotely measuring the air temperature distribution in a space with a local heat source (e.g., data centers), which is a relatively difficult case for remote sensing methods. • Air temperature distribution was remotely measured by a spectroradiometer. • Maximum a posteriori method was used as a regularization for this measurement. • The effectiveness of the proposed method was validated through the experiment. • Ten spectral channels were sufficient in the spectroradiometer for this method. • When a heat source location was known, sensitivity was seen away from the sensor. [ABSTRACT FROM AUTHOR]

• Different neighborhood forms can create inter-neighborhood microclimate variability. • Local-specific characteristics affect microclimate differently across neighborhood area. • Influence of local-specific characteristics on microclimate vary across seasons. • Vegetation is more important in regulating microclimate in shallower than deeper canyon. Although neighborhood is the level where most local plans are realized, little research has been done to understand how neighborhood spatial characteristics can shape its microclimate. This study aims to understand the effect of neighborhood form on its microclimate in a hot arid city, in Egypt. Two neighborhoods with different layouts are selected- a low-density historic area and a modern high-density area. Each neighborhood form was analyzed according to seven spatial characteristics: aspect ratio, street orientation, street trees, green spaces, percentage of tree canopy and impervious surfaces at 20m radii, and sky view factor. Microclimate data was collected using mobile field measurements in summer and winter. In total air temperature, relative humidity and wind speed at 44 sites were measured. The statistical and spatial analysis reveal inter-neighborhood microclimate variation which is more observed in winter than in summer. Moreover, the local-specific spatial characteristics within each neighborhood have resulted in a variation in the microclimate across the neighborhoods. The study also found a seasonal effect on the overall microclimate and on the way local-specific characteristics influence the microclimate. Findings of this research can have implications for future (re)development and planning of climate resilient neighborhoods, in a hot arid context. [ABSTRACT FROM AUTHOR]

Air temperature is an important physical indicator for urban and architectural environments; however, it is difficult to obtain its distributive characteristics by field measurements owing to the limitations of current measuring instruments. In this context, this study was conducted to demonstrate whether a small and portable ground-based thermal infrared spectroradiometer can be used to estimate the horizontal air temperature distribution in built spaces. For this estimation, we first calculated a forward model using radiative transfer simulations, and the air temperature distribution was inversely estimated from the observed radiance using the model. To regularize the estimated air temperature, we used the maximum a posteriori method, which uses prior information. To verify this estimation method, we conducted measurement experiments in two types of built spaces that had different air temperature distributions within spaces that were approximately 20 m long. Moreover, we conducted a parametric case study on the prior information. As a result, we were able to estimate the air temperature distribution with an average root mean square error (RMSE) of 1.3 °C for all cases when the average RMSE of the prior information for all cases was 2.1 °C. This improvement in the RMSE indicates that this method is able to remotely estimate the horizontal air temperature distribution in built spaces. [ABSTRACT FROM AUTHOR]

Abstract: A building affects its surrounding environment, and conversely its indoor environment is influenced by its surroundings. In order to obtain a more accurate prediction of the indoor thermal environment, it is necessary to consider the interactions between the indoor and outdoor thermal environments. However, there is still a lack of numerical simulation tools available for predicting the interactions between indoor and outdoor microclimate that take into account the influences of outdoor spatial conditions (such as building forms and tree shapes) and various urban surface materials. This present paper presents a simulation tool for predicting the effect of outdoor thermal environment on building thermal performance (heating/cooling loads, indoor temperature) in an urban block consisting of several buildings, trees, and other structures. The simulation tool is a 3D CAD-based design tool, which makes it possible to reproduce the spatial forms of buildings and constructed surface materials in detail. The outdoor thermal environment is evaluated in terms of external surface temperature and mean radiant temperature (MRT). Simulated results of these temperatures can be visualized on a color 3D display. Building heating/cooling loads and indoor air temperature (internal surface temperature) can also be simulated. In this study, a simulation methodology is described, and a sensitivity analysis is conducted for a wooden detached house under different outdoor conditions (building coverage, adjacent building height, surrounding with trees or no-trees). Simulation results show that the simulation tool developed in this study is capable of quantifying the influences of outdoor configurations and surface materials on both indoor and outdoor environments. [Copyright &y& Elsevier]