Analysis of Reconstruction in Terms of CO2 Concentration

2019 ◽  
Vol 808 ◽  
pp. 39-45
Author(s):  
Mária Budiaková

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.

2019 ◽  
Vol 111 ◽  
pp. 01085
Author(s):  
Hiroshi Muramatsu ◽  
Tatsuo Nobe

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.


2013 ◽  
Vol 465-466 ◽  
pp. 571-577
Author(s):  
Ade Asmi ◽  
Jouvan Chandra Pratama Putra ◽  
Ismail Abdul Rahman

Airflow in a room can be supplied both through natural mean and also by the helps of mechanical ventilation. Natural ventilation is more sustainable compared to mechanical system; however natural ventilation, it may not be sufficient to fulfil the need of ventilation for a specific room. This study presents simulation works carried out regarding to the airflow movement in a room due to mechanical ventilation. The measurement of air velocity was taken using Davis anemometer at random point in the room. The measured air velocity then used as an input in simulation work which used Comsol Multiphysics software. The simulation process begins by building up geometry of the room, assigning constant parameters, meshing the geometry of the room, and finally run the solver analysis. The results from simulations indicate that the air distributions in the room are below ASHRAE standard. This is due to the airflow distribution from the airflow injection of air-conditioning system is not well distributed. The simulations results are validated with the measured value and found that the percentage differences between the simulated and measured values are within the range of 3 - 10 %. Keywords: Simulation, Airflow movement, Mechanical ventilation, Comsol Multiphysics software


2014 ◽  
Vol 13 (4) ◽  
pp. 007-013
Author(s):  
Dorota Koruba ◽  
Ewa Zender Świercz ◽  
Jerzy Piotrowski ◽  
Łukasz Orman ◽  
Marek Telejko

The article demonstrates the results of research on the indoor air quality (IAQ) in one of chosen preschools. In such facilities, the standard solution is a system of natural ventilation. Only a small percentage of such buildings is equipped with a mechanical ventilation system with adjustable parameters of the microclimate. The article presents the results of indoor air quality in the local preschool located in Kielce. In the present facility natural ventilation system was used. Preliminary studies confirmed the poor quality of indoor air in a subjected building. During the study, two improvements aimed at improving air quality were proposed. The first improvement was to increase the supply air stream. The second one concerned the installation of equipment for the treatment of indoor air. The results indicate that under certain guidelines it is possible to improve indoor air quality. As an indicator of indoor air quality, concentration of carbon dioxide was adopted. In addition, microbiological tests were performed indoors.


2015 ◽  
Vol 2 (1) ◽  
pp. 70 ◽  
Author(s):  
Feng-Chyi Duh

This study investigated transient effects on the air quality of parked cars and moving cars with and without operating air conditioning. Carbon dioxide, carbon monoxide, volatile organic compounds, and formaldehyde concentrations were measured for comparative analysis. The results showed that simply changing the air conditioning system from internal circulation to external circulation to introduce air from outside reduces carbon dioxide concentrations by more than 50%, volatile organic compound concentrations by more than 77%, and the heat index from 0.1℃/min to less than 0.05 ℃/min. In order to conserve energy and improve car indoor air quality, this study can serve as a reference on healthy car environments.


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