scholarly journals DESIGNING A SMALL CLIMATE CHAMBER TO CHARACTERIZE PEOPLE AS A SOURCE OF DETERIORATION OF INDOOR AIR QUALITY BY RESPIRATION

2019 ◽  
Vol 7 ◽  
pp. 954-959 ◽  
Author(s):  
Detelin Ganchev Markov ◽  
Sergey Mijorski ◽  
Peter Stankov ◽  
Iskra Simova ◽  
Radositna A. Angelova ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Carbon Dioxide Concentration ◽  
Air Distribution ◽  
Vapor Concentration ◽  
Cfd Simulations ◽  
Climate Chamber

: People are one of the sources for deterioration of the indoor air quality. They worsen indoor air quality by their presence (respiration, bio-effluents), activities and habits. Through respiration, people decrease the oxygen concentration in the air of the occupied space and increase carbon dioxide and water vapor concentration in the indoor air as well as its temperature. The goal of the AIRMEN project is to find out if the rate of consumption of oxygen and emission of carbon dioxide (and water vapor) by people depends on the indoor air temperature as well as carbon dioxide concentration in the inhaled air. In order to achieve this goal a small climate chamber must be designed and constructed which allows for controlling and measuring both inflow and exposure parameters as well as for measuring outflow parameters. The principal goal of this paper is to present some important details, obtained by CFD simulations, from the design process of the climate chamber which precondition the air distribution in the chamber and hence the exposure parameters.

scholarly journals Analysis of Carbon Dioxide Concentration Prediction Model and Diffusion Tendency of Expiratory by Simultaneous Multipoint Sensing

2020 ◽  
Vol 10 (13) ◽  
pp. 4631
Author(s):  
Motokazu Moritani ◽  
Norifumi Watanabe ◽  
Kensuke Miyamoto ◽  
Kota Itoda ◽  
Junya Imani ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Prediction Model ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Carbon Dioxide Concentration ◽  
Predicted Values ◽  
Carbon Dioxide Co2 ◽  
Intellectual Activities ◽  
And Diffusion

Recent indoor air quality studies show that even 1000 parts per million (ppm) concentration of Carbon Dioxide (CO2) has an adverse effect on human intellectual activities. Therefore, it is required to keep the CO 2 concentration below a certain value in a room. In this study, in order to analyze the diffusion tendency of carbon dioxide by breathing, we constructed a simultaneous multi-point sensing system equipped with a carbon dioxide concentration sensor to measure indoor environment. Furthermore, it was evaluated whether the prediction model can be effectively used by comparing the prediction value by the model and the actually measured value from the sensor. The experimental results showed that CO 2 by exhaled breathing diffuses evenly throughout the room regardless of the sensor’s relative positions to the human test subjects. The existing model is sufficiently accurate in a room which has above at least a 0.67 cycle/h ventilation cycle. However, there is a large gap between the measured and the model’s predicted values in a room with a low ventilation cycle, and that suggests a measurement with a sensor still is necessary to precisely monitor the indoor air quality.

scholarly journals Method for Estimation of CO2 Gains from Persons in Builidings

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1309 ◽  
Author(s):  
Antonio Rodero ◽  
Dorota Anna Krawczyk
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Carbon Dioxide Concentration ◽  
Co2 Concentration ◽  
Males And Females ◽  
Sources Of Co2

Carbon dioxide concentration is an important parameter to know Indoor Air Quality of a building. One of the most important sources of CO2 in poor ventilated building is human activity. This work presents a method for experimental determination of human CO2 generation rate based on measuring of time evolution of indoor CO2 concentration. The method is applied to 5 rooms of an educational building from Bialystok (Poland). Similar carbon dioxide gains were obtained in all rooms, around 0.0046 L/s, which correspond to theoretical CO2 generation rates of a sedentary activity for persons, males and females, between 21–30 years old, characteristics of occupants of analyzed rooms.

scholarly journals Practical Impact of the COVID-19 Pandemic on Indoor Air Quality and Thermal Comfort in Kindergartens. A Case Study of Slovenia

2021 ◽  
Vol 18 (18) ◽  
pp. 9712
Author(s):  
Vesna Lovec ◽  
Miroslav Premrov ◽  
Vesna Žegarac Leskovar
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Air Temperature ◽  
Indoor Air ◽  
Carbon Dioxide Concentration ◽  
Building Stock ◽  
Practical Impact

The experimental monitoring of carbon dioxide concentration was carried out in kindergartens in Slovenia, together with indoor air temperature and relative humidity, before and during the COVID-19 pandemic. The aim of the research was to estimate the practical impact of the pandemic on indoor air quality and thermal comfort. The case study sample included buildings with different architectural typology, which are predominantly present in the building stock of Slovenia. The monitoring process lasted for 125 days before and during the COVID-19 pandemic. The results have shown a better indoor air quality in kindergartens during the pandemic, mostly due to ventilation protocols and almost imperceptibly changed indoor air temperature. The COVID-19 pandemic affected air quality in kindergarten classrooms in Slovenia by reducing the average carbon dioxide concentration when children were present in classrooms by 30%.

scholarly journals Improving Ventilation Efficiency for a Highly Energy Efficient Indoor Swimming Pool Using CFD Simulations

Fluids ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 92 ◽  
Author(s):  
Gabriel Rojas ◽  
Jessica Grove-Smith
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Measurement Data ◽  
Swimming Pool ◽  
Air Distribution ◽  
Cfd Simulations ◽  
Indoor Swimming Pool ◽  
Ventilation Efficiency ◽  
Computational Resources

The operation of a typical indoor swimming pool is very energy intensive. Previous studies have shown that high quality thermal building envelopes, i.e., with high levels of insulation and airtightness, make it possible to rethink conventional ventilation concepts. Due to the reduced condensation risk in and on envelopes of high thermal quality, ventilation design can be optimized for indoor air quality rather than for averting condensation on the facade. This work investigates different air distribution concepts for an existing swimming pool via computational fluid dynamics (CFD) simulations to evaluate their ventilation efficiency. To reduce modelling and computational resources, the velocity and turbulence fields produced by the swirl-diffusers are determined in a set of separate CFD simulations and incorporated into the swimming pool models. The results show that the ventilation efficiency in the examined swimming pool could potentially be improved with various alternative air distribution concepts, therefore improving the indoor air quality. Although the results seem plausible and compare well with the limited measurement data of air humidity, a more formal experimental validation is still needed before generalizing recommendations.

scholarly journals 3D Correlation IAQ in a Conference Room

Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 2
Author(s):  
Katarzyna Gładyszewska-Fiedoruk
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Relative Humidity ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Pollutants ◽  
Carbon Dioxide Concentration ◽  
Conference Room ◽  
Sources Of Pollution ◽  
Measurement Results

The work presents an attempt to understand how three basic air pollutants in a room have an influence on indoor air quality. The aim of the study is to analyze the air quality in a conference room, determining whether (and if so, which) correlations occur among air pollutants in a room where the only sources of pollution is people. The air temperature, relative humidity and carbon dioxide concentration in the air in the room were analyzed. When analyzing the correlation among the measurement results, it should be clearly stated that the impurities that come only from people are correlated with each other.

scholarly journals Exhaled Carbon Dioxide as a Physiological Source of Deterioration of Indoor Air Quality in Non-Industrial Environments: Influence of Air Temperature

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8127
Author(s):  
Radostina A. Angelova ◽  
Detelin Markov ◽  
Rositsa Velichkova ◽  
Peter Stankov ◽  
Iskra Simova
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Air Temperature ◽  
Pulse Rate ◽  
Indoor Air ◽  
Co2 Concentration ◽  
Physiological Parameters ◽  
Climate Chamber ◽  
Air Temperatures

People are the main reason for the deterioration of indoor air quality (IAQ) due to the continuous physiological metabolism processes in their bodies, including respiration. We present results from an investigation of the influence of indoor air temperature on the concentration of exhaled carbon dioxide (CO2). The investigation was preconditioned by previous findings on the effect of air temperature on human metabolism. However, our literature survey showed a lack of studies on the influence of the indoor air temperature on the exhaled CO2 (or metabolic CO2), which leads to the novelty of our results. Our experiments had two phases: measurement in a university classroom with an installed heating, ventilation, and air-conditioning (HVAC) system during regular classes and measurement in a specially designed small climate chamber, where the time variations of the CO2 concentrations, together with some physiological parameters, were measured. Two indoor air temperatures were set: 23 °C and 27 °C. The results obtained and their respective analyses show the strong effect of the two air temperatures on the CO2 concentration due to exhalation. In the classroom, the CO2 concentration at 27 °C was higher by 6.2% than at 23 °C. In the climate chamber, the CO2 concentration at 27 °C was higher by 9.6% than at 23 °C. Physiological parameters (oxygen saturation pressure, pulse rate, end-tidal CO2, and respiration rate) and their dependence on the air temperature were also measured in the climate chamber, establishing an effect of the temperature on the pulse rate.

CFD Analysis on Thermal Comfort and Indoor Air Quality Affected by Partitions in Air-Conditioned Building

2016 ◽  
Vol 836 ◽  
pp. 121-126
Author(s):  
Pradip Aryal ◽  
Thananchai Leephakpreeda
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Carbon Dioxide Concentration ◽  
Average Concentration ◽  
Cfd Analysis ◽  
Carbon Dioxide Concentrations

This paper presents a CFD analysis on thermal comfort and indoor air quality affected by partitions in an air-conditioned building. CFD experiments are carried out to simulate variables of indoor air before/after installation or removal of partitions. Accordingly, the Predicted Mean Vote (PMV) is determined as an indicator of thermal comfort while the carbon dioxide concentration within an air-conditioned space is used for the assessment of indoor air quality. Some simulated results are validated by measurements with good agreement where a case study is conducted in an air-conditioned space of a library. With the proposed methodology, it can be recommended in a case study that the significant effects of partition on thermal comfort are observed where the area with neutral sensation and slightly-cool sensation reduces significantly. The occupants feel uncomfortably cold after installing partition. The carbon dioxide concentrations slightly increase in some areas but the average concentration remains acceptable according to ASHRAE standard. Without the reinforcement of the air-conditioning units, the installation of partition at the desired location is not encouraged regarding to occupant’s thermal comfort and indoor air quality.

Effects of Partition on Thermal Comfort, Indoor Air Quality, Energy Consumption, and Perception in Air-Conditioned Buildings

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Pradip Aryal ◽  
Thananchai Leephakpreeda
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Energy Savings ◽  
Carbon Dioxide Concentration ◽  
Peak Time ◽  
Cfd Analysis

This research is to assess effects of a partition on thermal comfort, indoor air quality (IAQ), energy consumption, and perception in an air-conditioned space via computational fluid dynamics (CFD) analysis. The variables of indoor air are numerically determined before/after installation/removal of a partition. Accordingly, predicted mean vote (PMV) of thermal comfort, carbon dioxide concentration, rate of energy consumption in making up air, and an overall perception index are proposed to quantify effects in a partitioned space. For a case study, a partition is used to tightly separate a study area from a rest area in a library during peak time. The CFD analysis is performed so that the mean differences between the measured and simulated variables at 14 locations are less than 5%. After partitioning in the CFD analysis, it is found that the average PMV value decreases to −1.4 in the rest area, and it remains at −0.7 in the study area where occupants perceive a slightly cool sensation. In the study area, the carbon dioxide concentration increases to 450–500 ppm, while the rate of energy consumption increases by 8.3%. From the overall perception index of 0.9, the occupants feel spacious in the partitioned areas. Therefore, installing the partition is encouraged with the recommendation that cooling supply can be reduced for energy savings. It is apparent that the proposed methodology yields quantitative indicators for decision making of installation/removal of partitions. The interior investigation of partitions in buildings can be performed before making real physical changes.

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