Papers by Keyword: CO₂ Concentration

Abstract: The paper focuses on the analysis of reconstruction in terms of CO₂ concentration. The reconstruction at the university included the exchange of windows. The original windows were exchanged for the modern wood tight windows. Providing CO₂ concentration in the interiors of a university is immensely important for the students of the university. Not exceeding CO₂ concentration limits is necessary not only for the physiological needs of students but also for the required performance of students. Teaching is conducted during the whole day in the researched university schoolroom. The short-term natural ventilation during the breaks is noticeably not sufficient. After 15 minutes from the beginning of the lesson, students started complaining about the air quality and they had to open the windows. To point out the unsustainable state of the poor air quality during the day-long teaching and to be able to prove the officials the importance of the continuation of the reconstruction by building mechanical ventilation or air conditioning system, there were carried out the experimental measurements in the schoolroom. The device Testo 480 was used for the measurements. Obtained values of CO₂ concentration are presented in the charts. Interestingly, this reconstruction significantly decreased the air quality. The admissible values of CO₂ concentration were exceeded after the first hours of teaching. These values were worsening with each additional hour of teaching. Therefore, another reconstruction is needed to enable the transition from natural ventilation to the mechanical ventilation system. In the conclusion of this paper, there are principles how to design new schoolrooms. Furthermore, there are presented recommendations how to operate the existing schoolrooms.

Abstract: The paper is oriented on the evaluation of the indoor climate in the big lecture hall. Providing the optimal parameters of the thermal comfort and the CO₂ concentration is immensely important for the students in the interiors of a university. Meeting these parameters is inevitable not only from physiological point of view but also for achieving the desirable students' performance. The high CO₂ concentration is related to incorrect and insufficient ventilation in the lecture hall and causes distractibility and feeling of tiredness of students. Experimental measurements were carried out in the winter season in 2016 in the big lecture hall in order to evaluate the thermal comfort and the CO₂ concentration. The device Testo 480 was used for the measurements. Obtained values of air temperature, air relative humidity, air velocity, CO₂ concentration are presented in the charts. Mechanical ventilation system and operation system of the big university lecture hall were evaluated on the basis of the parameters of the thermal comfort and on the basis of the CO₂ concentration. Based on the findings, design recommendations for new big university lecture halls are derived. Furthermore, there are presented recommendations how to operate the existing big university lecture halls.

Abstract: In the industrialized cultivation process of fungi, CO₂ concentration control system is a nonlinear, time-delay and time-varying system, which is difficult to establish a precise mathematical model. Considering the situation, CO₂ concentration prediction model that based on neural network was built, and a fuzzy controller was proposed further based on the prediction model. Finally, matlab/labview based online forecast model was finished, and it is verified that the prediction system has higher prediction accuracy with robust character. It also provides a new approach to control key environmental factors under more favorable conditions for mushroom growth.

Abstract: The operating mode of the building, its occupancy and user behaviour has a significant impact on the CO₂ concentration and on the internal temperature of the room and therefore on the quality of the indoor environment and on the overall energy performance of the building. This paper summarises results from dynamic thermal modelling software combined with an air flow model for the assessment of a natural ventilation potential in office premises of the building not only with regards to the internal temperature, but also to the CO₂ concentration.

Abstract: A reflection function was established, based on leaf gas exchange process and tested with experimental data of eight kinds of plants, i.e. tomato, muskmelon, capsicum, maize, grape, onion, Haloxylon Ammodendron Bunge and Caragana Karshiskii Kom, with multifarious biological characteristic, water and growing status. The function indicated that the leaf stomatal conductance could be linearly reflected by the ratio of humidity and CO2 concentration at leaf surface, and the behaviour of its slope could be recognized as an indicator of leaf gas exchange efficiency, which had a negative relationship with leaf water use efficiency (WUE). The results maybe increase our understanding of potential influences of leaf stomatal conductance on photosynthetic and transpiration gas exchange and leaf WUE.