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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 study assesses American Society of Heating, Refrigerating and Air-Conditioning Engineers Guideline 36 (G36) with a typical medium office building. Specifically, this study employed a Modelica model of a variable air volume (VAV) system that serves this building, which includes components for representing indoor virus transmission and filtration. It then implemented the G36 control sequences for both water-side and air-side equipment in Python. After that, this study conducted the assessment by co-simulating G36 and the Modelica model using the Building Operations Testing Framework. Unlike existing works, this work has three unique features: (1) It considers the interactions between control sequences for water-side and air-side equipment of the studied VAV system. (2) It assesses the performance of G36 from the perspective of IAQ. (3) It examines the short-term behaviors of the studied building under G36 to understand the control stability. This assessment confirms significant energy savings from G36, largely because of the interaction between supply air temperature and hot water controls. It also reveals a trade-off between the ability to slow the spread of virus and the energy performance via demand controlled ventilation. Lastly, it emphasizes the necessity of tuning local feedback control when implementing G36. • Evaluate interactions of air-side and water-side controls from Guideline 36. • Assess the performance of Guideline 36 considering IAQ under indoor virus scenarios. • Examine the control stability of Guideline 36 with high-fidelity dynamic models. • Energy performance may conflict with IAQ when using Guideline 36. • Local feedback control needs to be tuned to unleash the potential of Guideline 36. [ABSTRACT FROM AUTHOR]

To investigate the variation of classroom environment during typical lecture hours, repeated field measurements and intervention experiments for indoor temperature were carried out in a typical class (95 min in duration, 0.32–0.39 person/m2 of occupants density) in a spring semester of a university in Beijing. Environmental data were recorded every 5 min, including indoor temperature, relative humidity and carbon dioxide (CO 2) concentration. Additionally, volatile organic compounds (VOCs) were sampled and indoor air quality (IAQ) were evaluated repeatedly. The results of field measurements showed the average air temperature in the classroom ranged from 21.2 ± 0.8 °C to 26.8 ± 0.7 °C, relative humidity ranged from 23.1 ± 1.8% to 57.5 ± 0.2%, and the average concentrations of CO 2 and total volatile organic compounds (TVOC) were 1,291–1,833 ppmv and 159-1,178 ppbm respectively. The subjective evaluations collected during intervention experiments showed that perceived odor intensity by visitors upon entering the room increased significantly, meanwhile the satisfaction and acceptability of air quality reduced considerably at the indoor temperature of 27 °C than that at 24 °C. Present results suggest when the indoor temperature rises, it is necessary to increase the outdoor air supply rate to ensure air freshness in classrooms. Subsequently, the calculated CO 2 emission rate by students increased by 0.54 L/h per person for every 1 °C rise in indoor temperature. Corresponding to the control target of indoor CO 2 concentration of 1,000 ppmv, the outdoor air ventilation rate required to eliminate occupant-generated pollution needs to be increased by 0.25 L/s per person. • The air quality in a classroom during typical lecture periods was investigated. • The CO 2 emission rate of college students was estimated using indoor CO 2 levels. • Perceived air quality was reduced significantly as indoor temperature increased. • Personal CO 2 emission rate increases by 0.54 L/h for 1 °C rise in temperature. • Higher outdoor air supply rate is recommended when indoor temperature rises. [ABSTRACT FROM AUTHOR]

The aim of the Best Vent project was to find the optimal control strategy for demand-controlled ventilation (DCV) without compromising on indoor air quality. In this paper, we discuss control strategies that would ensure acceptable perceived air quality for unadapted users. This study is a part of a series of field studies where sensory panels of untrained persons visited classrooms at a school. The sensory panel visited classrooms occupied by different user groups, at different ventilation rates and temperatures, and in empty classrooms at different ventilation rates, and with different pollutant loads. This study aims to assess whether it would be reasonable to control the supply airflow rate towards a higher CO 2 setpoint at low air temperature, and still maintain the same perceived indoor air quality upon entry. The results indicate that the perception of indoor air quality does not deteriorate at higher CO 2 concentrations when the air temperature is kept at 21 °C as opposed to at 24 °C. Furthermore, an increase in air temperature yielded poorer perceived air quality scores at similar CO 2 concentrations in the classrooms. Our results indicate that a DCV-control strategy with a higher CO 2 setpoint in classrooms at low temperatures would not compromise perceived air quality. Further research would be needed to assess whether the same is true for indoor climate-related symptoms or performance. • Control strategies for demand-controlled ventilation are investigated. • The classrooms had two different levels of CO 2 and temperature. • Higher CO 2 setpoint at low temperatures will not compromise perceived air quality. • Perceived indoor air quality was assessed by an untrained sensory panel. [ABSTRACT FROM AUTHOR]