scholarly journals Development of a Wide-Range Non-Dispersive Infrared Analyzer for the Continuous Measurement of CO2 in Indoor Environments

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1024
Author(s):  
Trieu-Vuong Dinh ◽  
Joo-Yeon Lee ◽  
Ji-Won Ahn ◽  
Jo-Chun Kim
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Measurement Errors ◽  
Indoor Environments ◽  
High Concentration ◽  
Linear Calibration ◽  
Wide Range ◽  
Carbon Dioxide Co2

Carbon dioxide (CO2) is an indicator of indoor air quality. Ventilation based on the use of a CO2 indicator helps to prevent people from acquiring many diseases, especially respiratory viral infections. Therefore, the monitoring of CO2 is a pivotal issue in the control of indoor air quality. A nondispersive infrared (NDIR) analyzer with a wide range of measurements (i.e., ppmv to percentage levels) was developed for measuring carbon dioxide (CO2) in an indoor environment. The effects of optical pathlength and interfering gases were investigated. The pathlengths of the analyzer were varied at 4.8, 8, 10.4 and 16 m, and the interference gases were CO; NO2; SO2; H2O; BTEX (i.e., benzene, toluene, ethylbenzene and m-/p-xylene) and formaldehyde. The lower detection limit, selectivity and sensitivity were determined to evaluate the performance of the analyzer. It was found that different pathlengths should be used to produce linear calibration curves for CO2 from ppmv to percentage levels. As a result, a wide-range NDIR analyzer, coupled with flexible pathlengths from 4.8 to 10.4 m, was developed. In terms of interference, only H2O should be taken into account due to its high concentration in indoor air. CO should be considered in some special locations at the ppmv level. The measurement errors for ppmv and the percentage levels were 0.4 and 0.9%, respectively.

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 Correlation amongst Indoor Air Quality, Ventilation and Carbon Dioxide

2017 ◽  
Vol 9 (2) ◽  
pp. 179-192 ◽  
Author(s):  
N. L. Sireesha
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Sick Building Syndrome ◽  
Well Being ◽  
Ventilation Rate ◽  
Indoor Contaminants ◽  
Sick Building ◽  
Carbon Dioxide Co2

The calculation of carbon dioxide (CO2)  intensities can be employed to see the quality of indoor air and ventilation. The studies undertaken till date have been distorted. The current study summaries the association amongst carbon dioxide and building air quality and ventilation, with carbon dioxide being the marker to evaluate air quality and ventilation performance. High carbon dioxide intensities may show insufficient ventilation per occupant and high indoor contaminants intensities, resulting in the Sick Building Syndrome (SBI) Symptoms. The researcher assessed the literature related to indoor air quality (IAQ), ventilation, and building-linked health issues in schools linked to CO2 discharges and recognised general indicated building-linked well-being signs found in schools. A high rise in the ventilation rate or enhancement in ventilation efficacy and/or indoor contaminant source regulation would be anticipated to reduce the occurrence of chosen signs to its optimum.

scholarly journals Indoor Air Quality in Healthcare and Care Facilities: Chemical Pollutants and Microbiological Contaminants

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1337
Author(s):  
Alexandre Baudet ◽  
Estelle Baurès ◽  
Hélène Guegan ◽  
Olivier Blanchard ◽  
Monique Guillaso ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Fine Particulate Matter ◽  
Complex Mixture ◽  
Chemical Compounds ◽  
Chemical Pollution ◽  
Indoor Environments ◽  
Wide Range ◽  
Care Facilities

The indoor air quality of healthcare and care facilities is poorly studied. The aim of this study was to qualitatively and quantitatively describe the chemical pollution and the microbiological contaminations of the indoor environment of these facilities. Methods: A wide range of chemical compounds (39 volatile and 13 semi-volatile organic compounds, carbon dioxide, fine particulate matter) and microorganisms (fungi and bacteria) were studied. Sampling campaigns were conducted in two French cities in summer 2018 and winter 2019 in six private healthcare facilities (general practitioner’s offices, dental offices, pharmacies) and four care facilities (nursing homes). Results: The highest median concentrations of chemical compounds (μg/m3) were measured for alcohols (ethanol: 378.9 and isopropanol: 23.6), ketones (acetone: 18.8), aldehydes (formaldehyde: 11.4 and acetaldehyde: 6.5) and terpenes (limonene: 4.3). The median concentration of PM2.5 was 9.0 µg/m3. The main bacteria of these indoor environments were Staphylococcus, Micrococcus and Bacillus genera, with median bacterial concentrations in the indoor air of 14 cfu/m3. The two major fungal genera were Cladosporium and Penicillium, with median fungal concentrations of 7 cfu/m3. Conclusions: Indoor air in healthcare and care facilities contains a complex mixture of many pollutants found in higher concentrations compared to the indoor air in French hospitals in a previous study.

scholarly journals The Indoor Air Quality in Laboratory Buildings. A Case Study in Integrated Laboratory of UIN Sunan Ampel Surabaya

2019 ◽  
Author(s):  
Widya Nilandita ◽  
Ida Munfarida ◽  
M Ratodi ◽  
Dyah Ratri Nurmaningsih ◽  
Dedy Suprayogi
Keyword(s):  
Carbon Dioxide ◽  
Sustainable Development ◽  
Air Quality ◽  
Relative Humidity ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Co2 Concentration ◽  
Cross Sectional ◽  
Carbon Dioxide Co2

Indoor Air Quality (IAQ) is one of the critical issues in sustainable development related to human health as the primary goal. Sustainable development should address potential human exposure to pollutants and health impacts. The laboratory, as educational support in the university, has specific contaminants, but studies on IAQ and thermal comfort in the laboratory have not been studied. IAQ and thermal comfort in a laboratory are essential as they can affect the work and health of the researchers and staffs. The purpose of this study is to analyze indoor air quality in an integrated laboratory of UIN Sunan Ampel Surabaya. This research is a cross-sectional study. Data analysis was done by a quantitative descriptive method. The air quality parameters in the laboratory were temperature, relative humidity, and carbon dioxide (CO2) concentration. All settings compared to the air quality standard. The analysis on carbon dioxide (CO2) concentration, relative humidity (%RH), temperature (∘C) has shown that the indoor air does not exceed the standard according to ASHRAE standard and Health Ministry Regulation with the maximum concentration was 444,3 ppm. The fan installation and increased air filter to controlled humidity are the option to improve the indoor air quality.

scholarly journals Indoor Air Quality including Respiratory Viruses

Toxics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 274
Author(s):  
Antonio López ◽  
Esther Fuentes ◽  
Vicent Yusà ◽  
F. Xavier López-Labrador ◽  
Marisa Camaró ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Methodological Approach ◽  
Respiratory Viruses ◽  
Indoor Environments ◽  
Waiting Room ◽  
Consultation Room ◽  
Carbon Dioxide Co2 ◽  
Airborne Viruses

The detection of SARS-CoV-2 in indoor environments is a cause of increasing concern. In this study, three sampling methodologies have been used in order to collect SARS-CoV-2 and 17 other respiratory viruses in indoor air, combined with a new analytical process to analyze respiratory viruses. Different areas of an ophthalmological hospital were investigated for the presence of these airborne viruses. Moreover, indoor air quality (IAQ) parameters (carbon dioxide, CO2; carbon monoxide, CO; nitrogen dioxide, NO2; volatile organic compounds, VOCs; formaldehyde, HCHO; and particulate matter, PM) have been examined to study the relationship between IAQ and airborne viruses. All indoor air and surface samples assessed were found to be negative for SARS-CoV-2. Nevertheless, another airborne respiratory virus (HRV/ENV) was detected, illustrating that the methodology set out here is a suitable one. Regarding the results for the IAQ, chemical parameters studied in the hall and waiting room of the hospital presented acceptable values. However, in the doctor′s consultation room VOCs and HCHO show some instantaneous levels higher than the recommended guide values. The methodological approach described in this paper, integrating conventional IAQ and the assessment of bioaerosols, can be used in research and control programs aimed at promoting a healthy indoor environment.

Statistical Evaluation of Indoor Air Quality Changes after Installation of the PSD System in Seoul’s Metro

2011 ◽  
Vol 20 (1) ◽  
pp. 187-197 ◽  
Author(s):  
Min Jeong Kim ◽  
Yong Su Kim ◽  
Abtin Ataei ◽  
Jeong Tai Kim ◽  
Jung Jin Lim ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Operating Conditions ◽  
Indoor Environments ◽  
Multivariate System ◽  
Metro Station ◽  
Adverse Health Effects ◽  
Subway Stations ◽  
Tele Monitoring

The purpose of this study was to evaluate changes in the concentration of air pollutants in the indoor environments, which could be caused by seasonal changes or changes in operating conditions of subway metro stations. In fact, there are many different types of pollution that can cause contamination in subway stations, and changes in operating conditions can also lead to changes in the indoor air quality (IAQ). Therefore, in order to establish a proper management of IAQ, it would be necessary to evaluate the changes in IAQ according to the changes in conditions. To do this, the present study used a multivariate analysis of variance (MANOVA). The results of testing the hypothesis proved that two groups, divided by the condition of a platform screen door (PSD) system, could differ statistically. Furthermore, those multidimensional differences were caused by installation of a PSD system. When applied to a real-time tele-monitoring system, MANOVA could clearly identify the daily and weekly variations of IAQ in the subway station, as well as the PSD system’s condition. Accordingly, this method could be useful for developing a multivariate system to statistically evaluate the experimental IAQ results in order to optimise operating conditions in a subway metro station to improve IAQ, and to minimise adverse health effects on passengers by exposure to harmful substances.

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 Remote Work and the Environment: Exploratory Analysis of Indoor Air Quality of Commercial Offices and the Home Office

2021 ◽  
Author(s):  
Kamrie Sarnosky ◽  
Mark Benden ◽  
Leslie Cizmas ◽  
Annette Regan ◽  
Garett Sansom
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Home Office ◽  
Adverse Health Effects ◽  
Home Based ◽  
Increased Risk ◽  
Carbon Dioxide Co2 ◽  
Total Volatile Organic Compounds

Abstract Background: The COVID-19 pandemic has accelerated an already existing trend of individuals increasingly working remotely. With the growing popularity of remote working, specifically in a home office, there is a critical need to better understand and characterize the potential environmental differences between these two spaces. Indoor air pollution can have adverse health effects and impair cognitive functioning. Methods: This small pilot cohort study (N=22) recruited home and office workers to better understand the indoor air quality between these spaces. Air contaminants collected and assessed included PM10 and PM2.5, carbon dioxide (CO2), and total volatile organic compounds (TVOCs). Results: Findings showed a strong statistically significant increase in all measured variables within homes in comparison to traditional offices (p<0.001). For instance, The mean PM2.5 level in the traditional office space was 1.93 µg/m3 whereas it was more than twice this amount (5.97 µg/m3) in home offices.Conclusion: These results indicate that those who work from home are at increased risk due to longer exposures to higher levels of certain contaminants, the importance to better develop interventions to mitigate this reality is underscored by the fact that many workers will be moving to home-based offices in the coming years.

scholarly journals Transient Effects of Different Ventilation Methods on Car Indoor Air Quality

2015 ◽  
Vol 2 (1) ◽  
pp. 70 ◽  
Author(s):  
Feng-Chyi Duh
Keyword(s):  
Carbon Dioxide ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Heat Index ◽  
Transient Effects ◽  
Air Conditioning System ◽  
Carbon Dioxide Concentrations ◽  
Volatile Organic

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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