Indoor and Built Environment

In order to improve the utilization of solar energy absorbed by the building wall, a passive building technology, that is the wall implanted with heat pipes, had been proposed. In the present study, two rooms with the same environmental conditions were built, and the one with a wall implanted with heat pipes installed was taken as a test room and the other as a control. The dynamic heat transfer characteristics of a wall implanted with heat pipes in transition season and its impact on indoor thermal environment were studied experimentally. The results showed that the application of a wall implanted with heat pipes could increase the indoor temperature by about 0.5 °C and would assert a positive influence on the vertical distribution of temperature. The PMV-PPD values of two rooms were calculated to compare and evaluate the improvement in thermal comfort, and the results indicated that the wall implanted with heat pipes reduced the dissatisfaction rate by more than one seventh in comparison to the indoor thermal environment. Also, it enhanced the PMV value. Therefore, wall implanted with heat pipes as an auxiliary heat source has a good effect on the indoor thermal environment during the transition season.

This study investigated the impact of outdoor air pollutants on indoor air quality in a high-rise building, considering factors related to the seasons and air infiltration. Further, the impact of atmospheric weather conditions on air infiltration has been analysed in a downtown area of Suzhou, China. The influence of the outdoor air pollution rate on indoor air quality in the office building was investigated based on on-site measurements and computer simulations. Results showed that the impact of outdoor air pollutants on indoor air quality was highest in winter, followed by spring, autumn and summer. Furthermore, multiple factors, which affect the indoor air quality in a high-rise building, have been further investigated in this study, including stack effect, wind effect, infiltration rate, outdoor air pollution rate, seasonal change and air filter efficiency. The significant influence of these factors on the indoor air quality level with floor height variations has been verified. Based on the analysis, a high-efficiency filter is recommended to maintain healthy indoor air quality. Meanwhile, a double-filter system is required if a building is exposed to heavily polluted outdoor air considering the most substantial impact of outdoor air pollutants on indoor air quality in winter. Moreover, a numerical model of steady-state indoor PM_2.5 concentration was established to determine the suitable air filter efficiency and airtightness.

Nowadays, energy retrofit for existing buildings has become a worldwide approach to reduce total energy consumption. A wide range of energy-efficient retrofit measures is actively affecting the decision process, of which retrofit alternatives should be used. The existing study aims to evaluate the effects of façade retrofit measures in residential buildings in Cairo using life-cycle cost analysis. An extensive variety of façade retrofit alternatives was explored individually and combined. A hypothetical benchmark building was used as a reference to represent typical residential buildings in Cairo. DesignBuilder was adopted to assess and quantify the energy-saving potentials for the proposed measures. The evaluation process was based on a parametric analysis of four major façade parameters that are affecting building energy performance; exterior wall configuration, glazing type, window-to-wall ratio and external shading. Thermal characteristics for façade retrofit measures were analysed to give a better understanding of the thermal performance for each retrofitting case. Results showed that the most cost-effective alternative for façade retrofit is to install a 1 m overhang as an external shading device, which reached 1.4% life-cycle cost saving and 18% energy saving. Finally, a sensitivity analysis for the main life-cycle cost supplements was presented to show major variables that are affecting life-cycle cost analysis.

The study investigates a hybrid radiant cooling system's potential to achieve thermal comfort. The hybrid radiant cooling (HRC) system combines the best features of a typical all-air and conventional chilled radiant cooling system. An HRC system presents the advantages to (a) reduce vapour condensation and to (b) adjust the cooling output by using an Airbox convector. The three systems perceive thermal comfort in the predicted mean vote (PMV) between –0.5 and +0.5 at 25 and 27°C. In the room condition at 31°C, the all-air system has a lower thermal comfort level because the elevated airspeed is less effective when the mean radiant temperature (MRT) is low. This study suggests a cooling strategy to maximize the thermal comfort level by effectively utilizing the HRC in extreme conditions without extra cooling sources. When the designed set point indoor temperature is 25°C, the Airbox convector of the HRC fan can be off. However, if the indoor air temperature increases above 25°C, an occupant can activate the Airbox convector; the actual thermal output of HRC is increased, and the elevated airspeed can reduce the predicted percentage dissatisfied (PPD) level. Even in an extreme indoor thermal condition at 31°C, the HRC minimizes the PPD level.

In order to ensure indoor air quality safety, locating the airborne contaminant sources accurately and quickly is extremely important so that timely measures can be taken to undermine the spread of pollutant and even eliminate the negative effects. Previous studies have shown that the multi-zone model can greatly reduce the inverse calculation time. However, the multi-zone model cannot describe the details of the indoor velocity field, which limits its application in complex multi-zone or large space buildings. On the premise of the accuracy and computational speed, based on the joint probability method, this study adopted the coarse-grid CFD method to speed up the process of acquiring the indoor airflow field, together with the multi-zone model method, to perform the inverse calculation of indoor airborne contaminant source location. In the backward calculation process, we conducted the ‘transpose' of the velocity field to obtain adjoint matrix, instead of computing ‘negative' of the velocity vector to save the calculation time. A two-dimensional ventilation model was utilized to validate the method, which proved the accuracy and time-saving potential of it. This study provides theoretical and practical prospect for the real-time inverse calculation of locating the indoor airborne contaminant sources.

Buildings are significant consumers of energy and producer of greenhouse gases worldwide, and serious efforts have been put into designing energy-efficient buildings. Significant technological advances have been achieved in developed countries; however, advances have rarely been adopted in developing countries like Afghanistan. Such trends emerge from the lack of research in designing energy-efficient buildings to local conditions, practices and materials. This research focused on building energy modelling and simulation to evaluate the energy performance impact of different shading and orientation. The research design follows a case study over an actual seven-storey multi-apartment residential building in the city of Mazar-I-Sharif, Afghanistan, using primary field data and dynamic simulation. Findings demonstrated that neighbouring structures have a positive correlation with a cooling demand. Meanwhile, south is the optimal orientation to face the building's glazed façade, saving up to 7.4% of cooling and 9.7% of heating energy. Moreover, movable shading devices installed on the building's openings in the summer season reduce the building energy load up to 19%, with a total energy cost reduction of AFN. 188,448 ($2447.37 US) annually. The study underlines the vast research scope in customizing building designs to Afghanistan's climatic conditions and other developing countries, thus contributing to buildings’ sustainability.

Hypoxia plays a major role in limiting the construction of the high-altitude mine. Understanding the effect and the distribution of diffused oxygen supply at different altitudes is the premise for the design of a mine with oxygen supply system and the full utilization of oxygen resources. For the optimal design of an oxygen supply mode and ventilation system, a multi-component fluid model of the diffused oxygen supply of a single-head tunnel was developed. This study reveals the variation law of the average oxygen mass fraction at different altitudes. The relationship between the distance from the heading face and the oxygen mass fraction at each altitude was fitted. The results show that the distribution of oxygen mass fraction in a single head tunnel at different altitudes presents a similar trend of increasing first and then decline. In addition, the change of the average oxygen mass fraction with the increase of altitude is not linear, and the dispersion loss is larger in high-altitude areas. The largest oxygen enrichment area is distributed at the altitudes of 4000–4500 m. This study provides theoretical support for improving the hypoxic environment of high-altitude metal mines excavation work.

A numerical heat and mass transfer model with thermophysical properties dependent on the temperature, humidity ratio and atmospheric pressure was developed. The numerical model was verified and validated against literature, and it showed good agreements. The pseudo-transient model provides a low-cost computational tool to evaluate the potential and performance of a dew point evaporative cooling system for a wide range of extreme climate conditions (BWh, BSh, Cw and Aw from Köppen classification). A parametric analysis of different operational and design conditions in the evaporative cooler was conducted. Results show that there is an optimal channel length for given climatic conditions. The Dew-point evaporative cooling (DPEC) system showed that the best thermal performance corresponds to the climate very arid (Hermosillo – BWh) with 4018 comfort hours (83.1%) followed by the climate arid (Monterrey – BSh) with 3470 comfort hours (90.9%), the mild climate (Puebla – Cw) with 295 comfort hours (100%) and the warm climate (Cancun – Aw) with 3452 comfort hours (62.3%). Finally, an engineering correlation for constant atmospheric pressure and channel length was obtained ( R adj 2 of 93%).

Thermal comfort depends on four environmental (air velocity, relative humidity, air temperature, mean radiant temperature) and two personal (clothing insulation and metabolic rate) parameters. Among all parameters, the mean radiant temperature (t_r) is the most problematic variable in thermal comfort studies due to its complexity. Measurement methods, calculation methods and assumptions are mostly used to obtain the t_r. Researchers mainly prefer to obtain the t_r via measurement methods or assumptions due to their easiness compared to the calculation methods. Besides, some researchers use constant values of angle factors in calculation methods. However, using constant values is not proper for every indoor environment, and it causes wrong estimations in the t_r and thus the thermal comfort. This paper gives the importance of calculation of angle factors, with an example of a university office building in temperate climate zone, according to the ISO 7726. The angle factors of the room were calculated for a seated occupant from the centre of gravity in three different locations and compared with the constant angle factors. The results indicate that a significant difference (MAPE of 1.02) was found in the t_r values, which were obtained by calculation of constant values of angle factors.

Nowadays, urban and community resilience have become the core issues of urban theoretical research and construction practices. While there are many studies on climate change, natural hazards and environmental pollution, relatively less attention has been paid to public and human health. However, the current COVID-19 pandemic, which is a major global public health crisis, is posing severe challenges to the resilience of cities and communities in the context of high-mobility, high-density and high-intensity, as well as expands the connotation of community resilience to public health. To compensate for the lack of current research, this study examined the characteristics of community medical facilities in response to pandemics at urban, community and individual multi-spatial scales based on a thorough review of current research and relevant practice. It also emphasized the significant role played by community medical facilities in improving resilient community constructions in the face of large-scale public health emergencies. These characteristics were fully utilized to explore ways to build and govern the ‘resilience' of communities in the future, help people to survive better as well as develop in complex and changeable external environments.

Under the bidirectional flow pattern of urban and rural factors, the tourism industry has become an important way to promote the vitality of urban and rural areas because of rural gentrification and city migration. By constructing a ‘node-link-setting’ networked land use model, this paper maps the tourism flow and geographic space networks, proposes a multi-layer nested network theory with spatial relevance from the mobility perspective to solve practical problems, such as urban–rural dual opposition and functional segmentation. We studied the high-precision mobile smart phone signalling data combined geographical data of Yichang, analysed the dynamic change process and comprehensive development mode characteristics of tourism attractions in 92 villages and towns through the social network analysis, compared tourism flow network changes in Yichang over time to construct a tourism flow network of Yichang, analysed the level and location of tourism nodes in the network and classified the tourist destinations to reveal the spatial-temporal evolution process and change the rule of the tourism flow network. The differences were compared by constructing traffic geography and infrastructure networks. The purpose is to propose guidance countermeasures for regional village unit tourism facility construction and industrial development and to maintain the integrity of spatial correlation and structural optimisation.

Natural ventilation can cool down the indoor environment and improve the air quality of buildings without consuming energy. The configuration of an inner corridor with double-sided classrooms is widely used in school buildings because of advantages such as space-saving and compactness. However, the inner doors or windows on the corridor side of these classrooms are often closed due to the dispersion of pollution and noise between classrooms. To introduce more fresh air from the outside, this study proposes a novel design to set up a horizontal airflow channel through the building to provide cross-ventilation for classrooms on both sides. A computational fluid dynamics (CFD) model was verified using experimental data and was employed to predict the airflow rate of the air channel by investigating different, sizes of air channels, wind directions, wind velocities and climate data, to assess the potential of the technology. The implementation of a channel area-to-floor area ratio of 2% (1.8 m²) provided an average increase in the ventilation rate of 215% on an annualized basis when applied and simulated in typical conditions from 10 different cities in China. This technology could be used to improve natural airflow rates in other buildings which use interior corridors in their design.

The influencing degree of different factors on terminal energy consumption of public building varies distinctly. If the actual measured terminal energy consumption is directly analyzed, the comparison basis is often inconsistent, which may lead to errors of results. In order to evaluate the energy consumption based on a unified standard, eliminating the interference of influencing factors, the standardization and revision of the measurement value of the terminal energy consumption is necessary. By considering domestic public building samples of different climate regions as research objects, this research has introduced a dimensionality reduction and integration method for evaluating influencing factors that could affect the terminal energy consumption of public buildings based on principal component and clustering analysis. Then, the quantitative mathematical expressions of the relationship between terminal energy consumptions and influencing factors were established through multiple linear regression fitting, formulating the standardized mathematical model of the terminal energy consumption of public buildings. According to the energy consumption standardized model, the evaluation approach was provided and scored based on mode analysis method. This approach can evaluate terminal energy consumption level and energy efficiency potential, analyzing the level of terminal energy consumption of public buildings in China.

This study aimed to determine how light direction, window proximity and window dimensions could affect students' perceptual evaluations in design studios. The design studios of the Nuh Naci Yazgan University in Kayseri were selected as the research setting. The ‘semantic differential scale’ composed of 10 adjective pairs was used for determining subjects’ perceptual evaluations of design studios having two different window dimensions. According to the results obtained, when making drawings, right-handed students who received light from a window on the left side were determined to perceive the physical environmental factors of design studios more positively compared to students who received light from a window on the right side. In addition, students sitting near a window in design studios were observed to generally perceive the physical environmental factors more positively than those sitting in the middle close to the window, in the middle away from the window and inside. Furthermore, students who sat in an area with floor to ceiling window were determined to perceive the place more positively compared to those who sat in an area with parapet to ceiling window. These results generally confirmed that light direction, window proximity and window dimensions in design studios are effective on students’ perceptual evaluations.

Condensation is a major issue in the safe operation of utility tunnels. To address the condensation problem, the indoor air temperature, relative humidity (RH) and surface temperature in an urban utility tunnel in Jining were continuously measured, and the condensation conditions were surveyed and analysed. The results indicated that under natural ventilation conditions, the air temperature in the comprehensive cabin varied from 23.4°C to 24.5°C, the RH fluctuated between 86.4% and 95.3%, and the corresponding air dew point temperature (DPT) remained in the range of 22.2°C–22.9°C. The surface temperature of the water supply pipeline ranged from 17.8°C to 18.5°C, which was far lower than the DPT in the tunnel, resulting in serious condensation. A water supply pipeline with an anti-condensation design was developed based on environmental test data. A 25-mm-thick rubber plastic sponge insulation layer was used to thermally insulate the water supply pipeline, preventing further dew condensation. Furthermore, mechanical ventilation had little effect on reducing the RH in the tunnel and may actually cause dew condensation; therefore, a ventilation control mode was proposed in this study. These results are expected to provide basic data for further research and reference for the safe management of utility tunnels.

Since the COVID-19 pandemic, the ventilation of school buildings has attracted considerable attention from the general public and researchers. However, guidance to assess the ventilation performance in classrooms, especially during a pandemic, is still lacking. Therefore, aiming to fill this gap, this study conducted a full-scale laboratory study to monitor the CO₂ concentrations at 18 locations in a classroom setting under four different ventilation regimes. Additionally, a field study was carried out in two Dutch secondary schools to monitor the CO₂ concentrations in the real classrooms with different ventilation regimes. Both the laboratory and field study findings showed that CO₂ concentrations varied a lot between different locations in the same room, especially under natural ventilation conditions. The outcome demonstrates the need of monitoring the CO₂ concentration at more than one location in a classroom. Moreover, the monitored CO₂ concentration patterns for different ventilation regimes were used to determine the most representative location for CO₂ monitoring in classrooms. For naturally ventilated classrooms, the location on the wall opposite to windows and the location on the front wall (nearby the teacher) were recommended. For mechanically ventilated classrooms, one measurement location seemed enough because CO₂ was well-mixed under this ventilation regime.

Urban environments are characterised by high pollution levels, which adversely affect the physiology, psychology and behaviour of the urban residents. In this study, on-site measurements and air quality evaluations were performed in urban residential areas. The negative air ion (NAI) concentration, fine particulate matter (PM_2.5) concentration, temperature and relative humidity were measured in different seasons. Both PM_2.5 and the NAI concentrations changed significantly with seasons. The PM_2.5 concentration was the highest in winter, intermediate in autumn and the lowest in summer, while the NAI concentration showed an opposite trend. The overall changes in NAI and PM_2.5 concentrations showed a trend of double peaks and double valleys, and there was a substantial difference between rainy days versus sunny days. The NAI concentration was positively correlated with temperature and relative humidity, and the influence of relative humidity on NAI was greater than that of temperature. There were notable spatial differences in the intensity of impact by different pollution sources. Based on these results, suggestions were made for optimising the layout of residential buildings and the rationalisation of traffic networks, with the aim of increasing NAI concentrations and reducing PM_2.5 concentrations. This would help reduce the pollution levels in urban residential areas.

Salt damage is one of the main problems facing the preservation of earthen sites in heritage museums. The use of salt-inhibiting materials on the surface of earthen sites to prevent damages could cause secondary damage. A method of placing a sand layer as a water and salt barrier was introduced and evaluated based on the law of unsaturated soil water and salt transport. The method involves placing a sand layer on the lower layer of the earthen site to inhibit the migration of water and salt from the deep soil to the surface of the earthen site. Experiments and numerical simulations were conducted to study the long-term effect and efficiency of water and salt barrier of sand layers with different particle sizes. The results show that the sand layer could successfully block the continuous upwards transport of water. The salt was shown to stagnate at the boundary between the bottom of the sand layer and the experimental soil. According to the simulation results, the water and salt barrier effect of the sand layer is proportional to the particle size of the sand layer. The sand layer with particle sizes much larger than the experimental soil has a durable water and salt barrier effect. These results are important for understanding the mechanism of salt damage to earthen sites and for the sustainable preservation of relics against salt damage in a soil environment.