scholarly journals Study the Impact of Engineering Ventilation on Indoor Air Quality in Hospitals during COVID-19

2021 ◽  
Vol 15 (2) ◽  
pp. 67-80
Author(s):  
Abderrahim Lakhouit ◽  
Hanaa Hachimi ◽  
Chakib El Mokhi ◽  
Adnane Addaim ◽  
Mohamed Kaicer
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
The Impact

scholarly journals Effects of Climatic Conditions, Season and Environmental Factors on CO2 Concentrations in Naturally Ventilated Primary Schools in Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Building Design ◽  
Climatic Conditions ◽  
Indoor Environmental Quality ◽  
Co2 Concentrations ◽  
The Impact

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.

scholarly journals Window operation behaviour and indoor air quality during lockdown: A monitoring-based simulation-assisted study in London

2021 ◽  
pp. 014362442110177
Author(s):  
Farhang Tahmasebi ◽  
Yan Wang ◽  
Elizabeth Cooper ◽  
Daniel Godoy Shimizu ◽  
Samuel Stamp ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Probabilistic Models ◽  
Performance Model ◽  
Outdoor Environment ◽  
Ventilation Strategies ◽  
The Impact

The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application: This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.

The impact of mechanical ventilation operation strategies on indoor CO2 concentration and air exchange rates in residential buildings

2020 ◽  
pp. 1420326X2096076
Author(s):  
Pedro F. Pereira ◽  
Nuno M. M. Ramos
Keyword(s):  
Mechanical Ventilation ◽  
Air Quality ◽  
Exchange Rates ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Residential Buildings ◽  
Ventilation Strategy ◽  
The Impact ◽  
Mechanical Extraction ◽  
Air Exchange

In Portugal, residential buildings commonly have their ventilation strategy changed after commissioning. This occurs due to the building managers' willingness to reduce shared costs with the electricity needed for fan operation. However, this option is not technically supported, and the effects of such a strategy on indoor air quality-related to human pollutants are yet to be quantified. CO2 was monitored in 15 bedrooms and air exchange rates were calculated for each room. The air exchange rate values ranged from 0.18 to 0.53 h−1 when mechanical extraction ventilation was off, and from 0.45 to 0.90 h−1 when mechanical extraction ventilation was on, which represents an average increase of 119%. With the current intermittent ventilation strategy, all rooms remain above 1500 ppm for a given percentage of time, and 12 rooms presenting CO2 concentrations above 2000 ppm. Simulations of theoretical CO2 concentrations, for a non-interrupted mechanical ventilation strategy show that no rooms would accumulate CO2 concentrations above 2000 ppm, and only 25% would present CO2 concentrations above 1500 ppm. Pearson correlations between the monitored CO2 and human and spatial factors identified two relevant parameters. Those parameters correspond to ratios between CO2 generation and floor area ([Formula: see text]), and airflow with CO2 generation ([Formula: see text]). The proposed ratios could be used as ways to optimise ventilation costs and indoor air quality.

scholarly journals Indoor air quality improvement and purification by atmospheric pressure Non-Thermal Plasma (NTP)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prince Junior Asilevi ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Bernard Fei-Baffoe ◽  
Yen Adams Sokama-Neuyam
Keyword(s):  
Air Quality ◽  
Built Environment ◽  
Indoor Air Quality ◽  
Removal Efficiency ◽  
Indoor Air ◽  
Thermal Plasma ◽  
Processing Parameters ◽  
Optimum Conditions ◽  
Non Thermal Plasma ◽  
The Impact

AbstractNon-thermal plasma (NTP) is a promising technology for the improvement of indoor air quality (IAQ) by removing volatile organic compounds (VOCs) through advanced oxidation process (AOP). In this paper, authors developed a laboratory scale dielectric barrier discharge (DBD) reactor which generates atmospheric NTP to study the removal of low-concentration formaldehyde (HCHO), a typical indoor air VOC in the built environment associated with cancer and leukemia, under different processing conditions. Strong ionization NTP was generated between the DBD electrodes by a pulse power zero-voltage switching flyback transformer (ZVS-FBT), which caused ionization of air molecules leading to active species formation to convert HCHO into carbon dioxide (CO2) and water vapor (H2O). The impact of key electrical and physical processing parameters i.e. discharge power (P), initial concentration (Cin), flow rate (F), and relative humidity (RH) which affect the formaldehyde removal efficiency (ɳ) were studied to determine optimum conditions. Results show that, the correlation coefficient (R2) of removal efficiency dependence on the processing parameters follow the order R2 (F) = 0.99 > R2 (RH) = 0.96, > R2 (Cin) = 0.94 > R2 (P) = 0.93. The removal efficiency reached 99% under the optimum conditions of P = 0.6 W, Cin = 0.1 ppm, F = 0.2 m3/h, and RH = 65% with no secondary pollution. The study provided a theoretical and experimental basis for the application of DBD plasma for air purification in the built environment.

scholarly journals Efficiency and Eco-Costs of Air Purifiers in Terms of Improving Microbiological Indoor Air Quality in Dwellings—A Case Study

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 742 ◽  
Author(s):  
Ewa Brągoszewska ◽  
Magdalena Bogacka ◽  
Krzysztof Pikoń
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Pollution Prevention ◽  
Average Concentration ◽  
Environmental Cost ◽  
Bacterial Aerosol ◽  
The Impact ◽  
Ecological Cost

Air pollution, a by-product of economic growth, generates an enormous environmental cost in Poland. The issue of healthy living spaces and indoor air quality (IAQ) is a global concern because people spend approximately 90% of their time indoors. An increasingly popular method to improve IAQ is to use air purifiers (APs). Indoor air is often polluted by bioaerosols (e.g., viruses, bacteria, fungi), which are a major concern for public health. This work presents research on culturable bacterial aerosol (CBA) samples collected from dwellings with or without active APs during the 2019 summer season. The CBA samples were collected using a six-stage Andersen cascade impactor (ACI). The CBA concentrations were expressed as Colony Forming Units (CFU) per cubic metre of air. The average concentration of CBA in dwellings when the AP was active was 450–570 CFU/m3, whereas the average concentration when the AP was not active was 920–1000 CFU/m3. IAQ, when the APs were active, was on average almost 50% better than in cases where there were no procedures to decrease the concentration of air pollutants. Moreover, the obtained results of the particle size distribution (PSD) of CBA indicate that the use of APs reduced the proportion of the respirable fraction (the particles < 3.3 µm) by about 16%. Life cycle assessment (LCA) was used to assess the ecological cost of air purification. Our conceptual approach addresses the impact of indoor air pollution on human health and estimates the ecological cost of APs and air pollution prevention policies.

Quantifying the impact of traffic-related air pollution on the indoor air quality of a naturally ventilated building

2016 ◽  
Vol 89-90 ◽  
pp. 138-146 ◽  
Author(s):  
Zheming Tong ◽  
Yujiao Chen ◽  
Ali Malkawi ◽  
Gary Adamkiewicz ◽  
John D. Spengler
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
The Impact

Renovation in hospitals: a case study on the use of control cubes for local repairs in health-care facilities

2020 ◽  
Vol 18 (3) ◽  
pp. 247-257
Author(s):  
Ehsan Mousavi ◽  
Vivek Sharma ◽  
Dhaval Gajjar ◽  
Shervin Shoai Naini
Keyword(s):  
Health Care ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Health Care Facilities ◽  
Repair Work ◽  
Content Type ◽  
Care Facilities ◽  
Pathogenic Agents ◽  
The Impact

Purpose The purpose of this study is to evaluate the effectiveness of the control cubes for dust control in health-care facilities. Research shows that more than 80% of pathogenic agents in hospitals are spread into the air, where they either remain airborne or deposit on the surface. At the same time, renovation and repair activities, including regular maintenance, are a necessity in active health-care facilities and a multitude of studies have documented their impact on indoor air quality. The dust that is generated by construction activities may potentially carry pathogenic agents, varying from coarse particles (≤10 µm, PM10) to fine particles (≤2.5 µm, PM2.5), including airborne bacteria, and fungal spores linked to high patient mortality in immune-compromised patients. Design/methodology/approach This study measures the impact and effectiveness of one such preventative measure, namely, the control cube (CC), on air quality during renovation and repair. CC is a temporary structure, typically made from stainless steel, around the local repair zone to minimize the spread of dust and potential microorganisms. The current paper presents a comparative analysis to identify the effectiveness of a CC equipped with the high-efficiency particulate filtration (HEPA) filter in a hospital setting by simulating construction renovation and repair work. Findings A baseline was established to measure the effectiveness of CCs and the impact of negative pressure on the indoor air quality in a hospital during simulated renovation work. Results showed that CCs are very effective in minimizing the spread of dust due to construction activities in the hospital. However, it is imperative to ensure that the air inside the CC is cleaned via filtration. Originality/value CCs are very effective, and this paper investigates the best approach for facility managers to implement this strategy.

Cooking in India: The impact of improved stoves on indoor air quality

1989 ◽  
Vol 15 (1-6) ◽  
pp. 341-352 ◽  
Author(s):  
Jamuna Ramakrishna ◽  
M.B. Durgaprasad ◽  
Kirk R. Smith
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
The Impact
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