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People tend to spend considerable amounts of time in buildings; thus the issue of providing proper indoor environmental quality is of significant importance. This paper experimentally analyses the subjective sensations of the occupants of intelligent and traditional buildings with the focus on possible differences between these two types of buildings. The study is based on a large database of 1302 questionnaires collected in 92 rooms where simultaneous measurements of the indoor environment physical parameters (air and globe temperature, relative humidity, carbon dioxide concentration, and illuminance) were carried out. Their impact on the subjective assessment of the indoor environment has been presented and analysed. The results show that the occupants seemed to be more favourable towards the indoor conditions in the intelligent building; however, the differences in comparison to the traditional buildings were not considerable. Similarly, self-reported productivity proved to be higher in the intelligent building, while the optimal range of air temperature, which ensured highest productivity, was 22–25 °C. Moreover, a strong correlation between the occupants' overall comfort and their perception of the air quality has been found. [ABSTRACT FROM AUTHOR]

This field study aimed to investigate naturally ventilated bedroom environment and its effects on subjective perception and sleep quality. Totally, 104 healthy subjects living in urban areas of Beijing participated in the study for one night during transition seasons. Bedroom environment parameters, including temperature, relative humidity, and CO2 concentration, were recorded before and during sleep. Objective sleep quality was measured by Fitbit Alta 2, a wrist‐type actigraphy sensor. Subjective assessments were collected by paper‐based questionnaires on sleep quality and environmental perceptions. The results showed that neutral temperature for waking state (before sleep) was estimated to be 23.8°C while for sleep state it was 26.5°C. Furthermore, pre‐sleep thermal sensation vote was found to be positively correlated with deep sleep percentage. Indoor air quality was correlated with sleep quality as indicated by statistically significant correlations between odor intensity assessment, air quality acceptability, average nightly CO2 concentration, and measures of sleep quality. For naturally ventilated bedrooms during transition seasons with a mild outdoor climate, present findings suggest that a bedroom with slightly warm pre‐sleep environment than neutral, and with high ventilation as indicated by low indoor CO2 concentration, could be beneficial for sleep quality of residents. [ABSTRACT FROM AUTHOR]

Housing environment has become a driving factor on hen health, egg quality and efficient production in intensive poultry industry. In large layer poultry housing system, an environmental index is typically used to control air conditions, including air temperature (T), relative humidity (RH) and concentration of carbon dioxide (CO2) in different season. In hot seasons, thermal environment of laying hen housing is usually assessed using the temperature humidity index (THI) via the online monitored temperature and relative humidity. However, the simple assessment cannot meet the harsh requirement of indoor air quality in a large layer house, as the stocking density increases in recent years. In this paper, a comprehensive environmental index (CEI) was proposed based on the radar map to integrate the impacts of both thermal and air quality factors, in order to systematically assess the environment comfort of the birds. A LabVIEW software system was selected to illustrate the environmental comfort using the fuzzy mathematics. Five key environmental factors, including temperature, RH, air velocity, concentration of CO2 and ammonia (NH3), were used to evaluate the environmental comfort of laying hen housing, where the their weights were normalized in a radar map. In the visualized system, early warning can be delivered when either a single factor or the CEI was over the prescribed value, and thereby a quick action can be taken to adjust the environmental conditions in the layer housing to a comfort level. A field measurement was carried out at a commercial layer breeder farm in Hebei province from January to February, and from July to August, 2019. The experimental results indicated that a good performance of the CEI can be obtained to assess the comprehensive environment in the tested house via monitoring the five environmental indexes. The specific sensors were properly settled in the henhouse. The data of environmental conditions was collected to verify, and then the maximum of five indexes were selected for later use. During the summer daytime, the CEI agreed well with the THI, indicating the positive impacts of thermal environment on the comfort of the birds, while it performed better to integrate the thermal and air quality at night time. In winter, the increase in the weight of CO2 concentration can contribute to the CEI for the comfort in layer housing system. The in situ monitoring data in the actual use demonstrated that the CEI can efficiently represent the change of comprehensive environmental comfort in the chicken house, and respond to the interaction between environmental factors in each period, especially when the air quality has an increasing influence on the comprehensive environmental comfort at night in summer and in winter. The findings can provide a promising method to systematically evaluate the housing environment via the five key factors in laying hen housing, further to improve the birds comfort via precisely controlling the air conditions in intensive poultry production. [ABSTRACT FROM AUTHOR]

The benefits of task ambient conditioning in improving thermal comfort and indoor air quality have been demonstrated in recent studies. The potential use of task ambient conditioning for improving thermal comfort when the room air temperature is beyond the suggested range in mixing ventilation; however, has not been fully explored. A newly developed task ambient conditioning with chest exposure was, therefore, suggested at the room air temperature of 28°C (82.4°F), which is higher than the normally set temperature under cooling conditions in mixing ventilation. The present study aims to explore the appropriate air parameter ranges of the local airflow, but not to develop the practical system. Assessments of the thermal environment were performed by subjective questionnaires under nine distinct conditions with task ambient conditioning with chest exposure as well as the ambient environment in a climate chamber. The thermal sensations under the nine conditions with task ambient conditioning with chest exposure were nearly thermal neutral or slightly cool, while a slightly warm sensation was experienced in an ambient environment. Thermal sensation votes indicated cooler sensations with a decrease in the temperature of the locally supplied air, and with an increase in the velocity of locally supplied air, as well as in the vent diameter. The locally supplied airflow of task ambient conditioning with chest exposure obviously improved thermal comfort, the percentage of discomfort was reduced to 20% or less. Furthermore, the appropriate ranges of airflow parameters (air temperature, air velocity, and vent diameter) of task ambient conditioning with chest exposure were demonstrated, to aid the practical development of task ambient conditioning with chest exposure systems. [ABSTRACT FROM PUBLISHER]

Previous studies have shown that poorly ventilated classrooms can have negative impact on the health of children and school staff. In most cases, schools in Serbia are ventilated naturally. Considering their high occupancy, classroom air quality test determines the level of air pollution, after which it is possible to implement corrective measures. The research presented in this study, was conducted in four schools which are located in different areas and have different architecture designs. Measurements in these schools have been performed during the winter (heating season) and spring (non-heating season) and the following results were presented: indoor air temperature, relative humidity, and carbon dioxide concentration. These results show that the classroom average concentration of carbon dioxide often exceeds the value of 1500 ppm, during its full occupancy, which indicates inadequate ventilation. Measurement campaigns show that carbon dioxide concentration increased significantly from non-heating to heating season in three of the four schools. Analysis of measurements also determined high correlation between relative humidity and carbon dioxide concentration in all schools in winter season. This fact may constitute a solid basis for the fresh air supply strategy. [ABSTRACT FROM AUTHOR]

As most residents spend more than 90% of their time in buildings, acceptable and reasonable control of both indoor thermal comfort and air quality is imperative to ensure occupants' health status and work productivity. However, current control strategies generally take either thermal comfort or indoor air quality as a single loop, rather than the concurrent control of two. To analyze their mutual influence, this study investigated the performance of three multi-control approaches, i.e., proportional integral derivative (PID) control of thermal comfort and a fixed outdoor air ratio, PID control of thermal comfort and design outdoor air rate, and PID control of thermal comfort and occupancy-based demand-controlled ventilation. As a pilot study, three typical control methods were implemented to a multi-zone building via OpenModelica modeling. The results indicate that indoor air temperature can be well-maintained under three control methods, however, the CO2 concentration under the fixed outdoor air ratio was over 1000 ppm, leading to poor indoor air quality. The control strategy with the design outdoor air rate could not properly ensure the CO2 concentration, due to the over-ventilated or under-ventilated phenomena, subsequently resulting in unnecessary energy waste. The occupancy-based demand controlled ventilation could maintain the CO2 concentration under the set-point with an intermediate power energy utilization. [ABSTRACT FROM AUTHOR]