Indoor and Built Environment

In the past 30 years, tubular daylight guide systems (TDGSs) have become one of the most popular ways to transport outdoor natural light into the inner space in building design. However, tubular daylight guide systems are not widely used because of the lack of methods to evaluate methods on the suitability of the TDGSs. This study therefore summarizes the daylight performance metrics of TDGSs and presents the estimation methods in terms of field measurements, simulation and empirical formulae. This study focuses on the daylight performance and potential energy savings of TDGSs. Moreover, this study will be helpful for building designers to build healthy, comfortable and energy-saving indoor environment.

Radon, thoron and their progeny concentration have been measured in dwellings located within a 90 km² area around a nuclear power plant using solid-state nuclear track detectors. Time-integrated measurements were carried out on a four-month cycle, making three measurements in each dwelling throughout the year. In total, 145 dwellings were selected for the study. The measured values of gas and their progeny concentrations were used to determine the equilibrium factor for radon and thoron indoors and annual inhalation dose. The average value of the equilibrium factor indoors was found to be 0.44 ± 0.23 for radon and 0.015 ± 0.010 for thoron. The annual inhalation dose for the public living around this plant was found to be 0.97 ± 0.55 mSv. Results were analysed for different seasons and different categories of dwellings for their construction type.

This paper aims to investigate the implication of present and future bioclimatic potential of passive heating and cooling design strategies for climate change scenarios of five locations covering all climate zones of India. Weather data for future climate change were developed for A2 (medium-high) scenario of the Intergovernmental Panel on Climate Change (IPCC) for four time slices, namely TMY (Typical Meteorological Year), 2020, 2050 and 2080. A case study residential building was used for calibration and validation of the bioclimatic potential using EnergyPlus simulation. Results show a strong correlation between the annual bioclimatic summer and winter discomfort hours and the corresponding annual cooling and heating energy load for the changing climate scenarios. Results also show an overall increase in annual cooling energy load, over and above the base case, ranging from 18% to 89% among the five cities in 2020; 32% to 132% in 2050 and 58% to 184% in 2080 if residential buildings continue to be operated in the same manner as it is done today without passive strategies. The use of passive strategies may reduce the annual cooling load by about 50%– 60% in residential buildings in future.

The experiment was targeted to develop design strategies and methods by testing the complex interplay between the dynamics of daylight and electrical lighting in an office. The double dynamic lighting design concept is based on the idea of adding task lighting, with a directionality referring to the daylight inflow and a variation on direct/diffuse lighting and respective changes in colour temperature respond to sky conditions and daylight levels. The experiment was conducted in an office space at Aalborg University in Copenhagen from September to December 2019. Four participants moved in and worked in the office with four-week periods of respective standard static lighting as a baseline, and dynamic lighting. In a parallel mixed method approach with interviews and questionnaires, the dynamic lighting was compared to the baseline and to a control group. The results indicate that the dynamic lighting periods had a positive effect on visual comfort, perceived atmosphere and work engagement. The studies helped to develop the definition of five dynamic light settings. Seasonal changes, time of day, dynamic sunscreens and individual needs for task lighting can be implemented in future field experiments as additional dynamic parameters to meet individual needs and circadian potentials for double dynamic light.

This work is centred on an ancient Italian church. Since 2011, a restoration plan has been undertaken by following sequential phases. The methodological approach to restoration was guided by environmental monitoring campaigns. In particular, two thermo-hygrometric campaigns were carried out during the warm months of the years 2015 and 2016. The first set of measurements was executed during the restoration of facades and roofs, making it possible to reach even areas that are usually difficult to access. The second set was performed to evaluate the indoor thermo-hygrometric conditions following the work of the previous year. This was intended to assess their differences in variability, the influence of the outdoor environment and any real and perceived improvement. Results demonstrate that thermal images helped in identifying both the heat sources causing thermal discomforts and the good thermal capacity of masonries. Concerning the heat index (HI), the church showed an improvement in the trend of malaise perceived by people during the second summer period (∼2°C lower than 2015). Finally, in the last microclimate monitoring, the roof structure no longer acted as an amplifier for daily temperature excursions.

The airflow distribution characterised by different large- and small-scale eddies in the aircraft cabin is the most important factor to maintain passengers' thermal comfort and to remove contaminants. The airflow distributions in narrow-body aircraft cabins are based on the principle of mixing ventilation. Opposing jets from air diffusers can cause stream deflection and oscillation, which results in the asymmetry of large-scale instantaneous airflow structures. This dynamic airflow structure is very important for analysing time series parameters. Therefore, this study applied numerical simulation to examine the oscillation and asymmetry of instantaneous airflow field structures and phase space reconstruction and used spectrum analysis to evaluate the oscillation amplitude and period of dynamic airflow structure. We also studied the factors that influence the dynamic airflow structure, such as air supply speeds, air supply angles and the strength of the thermal plume. The results showed that as the air supply speed increased, the swing amplitude of the instantaneous airflow structure increased, while the period decreased. The air supply angle affected the jet attachment and collision angle, which in turn affected the swing amplitude and period. The thermal plume restrained the formation of large-scale swings and contributed to the appearance of small-scale structures.

This study investigated effects of incident wind angles on wind velocity distributions in wakes of two generic building configurations, namely, ‘T’- and ‘+’-shaped, and the air pressure distributions along their leeward walls by using computational fluid dynamics simulations. Results show that when the wind approaches laterally (90°) (vs. when the wind is direct (0°)), the downwind length and maximum bilateral width of the low-wind velocity zone in the wake of ‘T’-shaped building decrease by 11.5% and 37.9%, respectively. When the incident wind is oblique (45°) (vs. when it is direct), the length and width of this low-wind velocity zone in the wake of ‘+’-shaped building decrease by 15.0% and 30.9%, respectively. Furthermore, results show that the air pressure on the leeward walls of the ‘T’- and ‘+’-shaped buildings gradually decreases along with the building height. The resulting low-wind conditions on upper floors of buildings reduce the fresh air intake of their leeward units utilizing natural ventilation. It is particularly apparent in the case of direct approaching wind. Thus, the appropriate selection of building configurations and their orientations allows for the most effective use of wind to enhance ventilation in indoor and urban environments.

Globalization and urbanization have caused unprecedented impacts in local identification and cultural protection, and rivers that cross administrative boundaries have attracted attention in the protection of local cultural heritage, resource integration and mobilization. This study selected several cities in the Yellow River Basin and the Rhine River Basin as examples, using street view images, combining locality theory with computer vision analysis methods, and proposing a framework for quantitative research on locality expression. Then the generation mechanism of the local characteristics was discussed. The results show that the cities in the two countries show significant differences, whereas some cities in the basin are similar. The images of the ‘Built Environment' and ‘Social Life' are more conducive to identifying the cities. The construction qualities of ‘Remains' and ‘Water' are the key built environmental factors for the coexistence of locality differences and similarities. The protection of historic buildings and less manual intervention in the water environment are of great significance to the local shaping of German cities and have reference value for developing Chinese cities. The research responds to the homogenization of the urban landscape, the symbiotic relationship between cities and water, and sustainable development in river basin cities.

A safe and effective evacuation route is important for reducing casualties during building fires, and this topic has been a long-term focus of emergency management. Indoor space is a space within one or multiple buildings consisting of architectural components and is the basis of indoor route analyses. Based on indoor space, an indoor network model is designed that considers fire protection design, spatial matching between fire information and the indoor space, and the passability of the indoor space during a fire. Then, an evacuation route selection algorithm that considers hazard and time is proposed. The key features of the route selection algorithm, which include assessing the fire hazards, evacuation time in each indoor space and parallel computing in the route selection algorithm, are subsequently presented. Finally, taking a gymnasium as an example, case modelling and fire information integration are performed to investigate two fire scenarios and the optimal evacuation routes over time are identified in each scenario.

The air flow and pollutant concentration fields in a street canyon affected by trees could affect the comfort and health of residents. At present, the description of the non-uniform/discontinuous distribution of leaves is difficult. In this study, the leaf distribution in the canopy was characterized by establishing non-continuous (uniform/random) algorithm based on a numerical simulation method, and the effects of canopy properties including, height, porosity and uniform/random leaf distribution, on the airflow and pollutant concentration fields in urban street canyons were investigated. The position of the tree canopy was found to directly affect the airflow field form and the air velocity distribution in the street canyon at low inflows. The average air velocity in the street canyon could be reduced significantly when the top of the tree canopy is near the top of the street canyon. The air velocity and pollutant concentration in the street canyon would vary only slightly due to the canopy porosity. Due to the increasing canopy porosity, the air velocity would increase, and the pollutant concentration would be reduced. The leaves are non-continuous and uniformly distributed at constant porosity, which does not significantly change the velocity distribution and pollutant concentration in the street canyon.

The district heating system that uses the hybrid operation of distributed variable speed pumps and regulating valves can effectively reduce the pressure level at the far-end of the heating network, while retaining the energy saving advantages of the distributed variable speed pump system and ensuring the safe operation of the heating network. In this study, pipe network optimization based on genetic algorithm was used to determine the pipe diameter required for the hybrid operation of distributed variable speed pumps and regulating valves. A mathematical model was established to evaluate the economic efficacy based on the annual equivalent cost. The zero-pressure difference point was evaluated to optimize the pipe diameter. A real pipe network was assessed to evaluate the efficacy of the method, and a sensitivity analysis of pressure constraints and economic factors was conducted. Our results show the system of hybrid operation of distributed variable speed pumps and regulating valves can reduce the annual equivalent cost by about 10.35% compared to the conventional central circulating pump system. In addition, the annual energy consumption due to heat loss and pump operation is only 0.36% higher than that of the conventional central circulating pump system.

In the current study, the performance of the counterflow dehumidification test rig using wood shaving packing has been analysed. Wood shaving packing with the density 500 kg/m³ was used along with the CaCl₂ desiccant with varying concentration. Mass flow rate of air was varied and the dehumidification performance parameters like moisture removal rate, dehumidification efficiency, coefficient of performance, change in relative humidity, change in the pressure and mass transfer coefficient were evaluated. Output parameters were compared with the commercially available cellulose packing with the wettability of 632 m²/m³. Results showed that, even though the performance of wood shaving packing is slightly less than the Celdek packing, performance of wood shaving is promising at 40% desiccant solution concentration. Maximum relative humidity difference, coefficient of performance and dehumidification efficiency obtained with wood shaving pad material were found to be 19%, 1.88 and 69.5%, respectively.

The legal regulations and cultural environment for smoking bans in hotels and motels in South Korea differ depending on the type of accommodation. The aim of this study was to assess the thirdhand smoke exposure for hotel and motel guests staying at accommodations who are expected to be relatively vulnerable to thirdhand smoke. Biomarkers for 28 participants were assessed before and after lodging at a hotel or motel for approximately 14 h. Hotel participants had statistically decreased urinary cotinine concentrations after their stay, whereas motel participants experienced increased concentrations. The concentration of nicotine-derived nitrosamine ketone in dust in hotels was lower than that in motels, and the higher dust nicotine-derived nitrosamine ketone concentration in motels had more effect on an increase in urinary cotinine concentration. Both hotels and motels legally allowed smoking in guest rooms. However, the study participants in hotels were less exposed to thirdhand smoke than those in motels.

Historic buildings in urban areas are valuable heritage and would require effective design for renovation to upgrade these buildings while preserving their heritage characteristics. This current study evaluated renovation requirements: loss of natural and spatial characteristics, single function and lack of building facade design, of a courtyard building in a Beijing historical district. Limitations of the ‘multiple coexistence’ design concept were analysed to fully achieve integration of historical, cultural, social, educational, commercial and economic values while preserving their natural characteristics. Intelligent control strategy and equipment can reshape the spatial lay out and natural environment, to enhance the building function and social value. The design strategy of the skylight to be installed in the courtyard was evaluated by simulation in this study. CFD simulation results show that the air temperature in the courtyard can increase 20% by incorporating a skylight that can be automatically closed in winter. During the summer, the skylight would be open to largely reduce the average air temperature by 1.2°C. The visual impact of external equipment can be mitigated by adding decoration to the courtyard facade. The findings should inform future development of a new design concept, to provide design paradigms for the renewal and renovation of similar historic buildings.

This research presents a comparative study and an indoor thermal comfort analysis of self-constructed dwellings with different roofing in the Lower Papaloapan River Basin in Mexico. These include concrete roofs, zinc-coated sheet metal, asbestos sheets and palm fronds, all with and without false ceilings. The comparative study takes into account the identification and analysis of different architectural typologies, materials, structural pathologies, as well as the construction processes and the number of hours in which a dwelling is inside the comfort zone proposed. Until now, there is no relevant information about the comfort zone for the inhabitants of the studied region. Thermal comfort analysis shows that the comfort zone for the region is difficult to achieve due to the temperature and humidity of the region. Among the roofing without a false ceiling, the dwelling with palm roofing had the best performance whilst housing with zinc roofing produced the worst. Moreover, palm roofing is an ecological and vernacular option that uses local materials. In the case of a false ceiling, a standardizing effect was observed for all types of roofing. New approaches to show and analyse data and some suggestions for improving comfort conditions within homes in the region were proposed.

Polycyclic aromatic hydrocarbons (PAHs) are a kind of carcinogenic, teratogenic and mutagenic pollutants that exist widely. In this study, a quarterly emission inventory of 16 PAHs listed as the US EPA priority pollutants was established by using the emission factor (EF) method. The results showed that the distribution of PAHs in different industries varied greatly with different year and quarter. The main characteristics of PAHs seasonal emission are that Q1 emission is the most and Q4 emission is the least. Among them, naphthalene and phenanthrene are the most important compounds. There are significant differences in PAHs emissions from different sources. Traffic and civil use emissions are the main sources. For example, in 2019, traffic emissions accounted for 20.9% and civil use emissions accounted for 78.3% of the total emissions. Then, a linear multiple regression model was established to predict the quarterly emission of PAHs. A vector autoregressive (VAR) approach was applied to analyse the correlation between the gross domestic product (GDP) and other macroeconomic parameters. This study could be used as a guide to provide recommendations for government policy and macro-control efforts.

Sick building syndrome is a group of symptoms relatively common among office workers; such symptoms could have an impact on the worker's productivity. The aim of this research is to provide a better understanding of the relation between design elements, indoor environmental quality and sick building syndrome within office spaces in Cairo, Egypt. Results show that a healthy environment leads to higher level of office productivity. Several design elements were chosen to be analysed according to previous studies, and their relation to the indoor environmental quality was noted. The prevalence of these elements on sick building syndrome was studied. An empirical comparative study has been conducted within two administrative office buildings at Cairo campus of the ‘Arab Academy for Science Technology & Maritime Transport' in Egypt. Data collection was done by a self-administrated questionnaire. The questionnaire includes personal background, work design elements, socio-demographic elements and symptoms of sick building syndrome. Headache and fatigue were the most prevalent symptoms in both buildings. This study revealed that office comfort is the most important factor affecting office occupants and should be taken seriously when designing office spaces for better working environment free of sick building syndrome.