scholarly journals The Effect of Mobile Indoor Air Cleaners on the Risk of Infection with SARS-CoV-2 in Surgical Examination and Treatment Rooms with Limited Ventilation Options

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Oberst M ◽  
◽  
Klar T ◽  
Heinrich A ◽  
◽  
...  
Keyword(s):  
Indoor Air ◽  
High Efficiency ◽  
Air Filtration ◽  
Air Filter ◽  
Filter System ◽  
Air Cleaner ◽  
Air Cleaners ◽  
Total Particle ◽  
Poor Ventilation ◽  
Examination Room

Objective: Due to the airborne transmission of the Coronavirus Disease (Covid-19) via aerosols, we investigated the effect of a mobile air filter system in a surgical examination room. Methods: A mobile indoor air cleaner (AP 90, DEMA-airtech, Germany) was run during regular surgical consulting hour in our outpatient’s clinic. Aerosol concentration was measured by Fidas Frog fine dust monitoring system (Palas, Germany) by constantly recording PM1.0, PM2.5, PM4, PM10 and the total particle load PMtot. Results: The use of the air filter system led to a significant reduction of aerosols in the room despite the fact that there were various numbers of persons in the room constantly. Conclusion: The use of a high efficiency air filtration device, especially in examination rooms with poor ventilation, e.g., lack of windows or local exhaust is recommendable.

scholarly journals Electrostatic Precipitators as an Indoor Air Cleaner—A Literature Review

2020 ◽  
Vol 12 (21) ◽  
pp. 8774
Author(s):  
Alireza Afshari ◽  
Lars Ekberg ◽  
Luboš Forejt ◽  
Jinhan Mo ◽  
Siamak Rahimi ◽  
...  
Keyword(s):  
Indoor Air ◽  
Indoor Environment ◽  
Indoor Environmental Quality ◽  
Air Filtration ◽  
Pressure Drops ◽  
Air Cleaning ◽  
Air Cleaner ◽  
Air Cleaners ◽  
Electrostatic Precipitators ◽  
Cleaning Technology

Many people spend most of their time in an indoor environment. A positive relationship exists between indoor environmental quality and the health, wellbeing, and productivity of occupants in buildings. The indoor environment is affected by pollutants, such as gases and particles. Pollutants can be removed from the indoor environment in various ways. Air-cleaning devices are commonly marketed as benefiting the removal of air pollutants and, consequently, improving indoor air quality. Depending on the type of cleaning technology, air cleaners may generate undesired and toxic byproducts. Different air filtration technologies, such as electrostatic precipitators (ESPs) have been introduced to the market. The ESP has been used in buildings because it can remove particles while only causing low pressure drops. Moreover, ESPs can be either in-duct or standalone units. This review aims to provide an overview of ESP use, methods for testing this product, the performance of existing ESPs concerning removing pollutants and their byproducts, and the existing market for ESPs.

Evolution of Gas Turbine Intake Air Filtration in a 420 MW Cogeneration Plant

2014 ◽  
Author(s):  
Steve Ingistov ◽  
Michael Milos ◽  
Rakesh K. Bhargava
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Economic Benefits ◽  
Cogeneration Plant ◽  
Air Filtration ◽  
Air Filter ◽  
Filter System ◽  
Turbine Performance ◽  
Filtration System ◽  
Operational Data

A suitable inlet air filter system is required for a gas turbine, depending on installation site and its environmental conditions, to minimize contaminants entering the compressor section in order to maintain gas turbine performance. This paper describes evolution of inlet air filter systems utilized at the 420 MW Watson Cogeneration Plant consisting of four GE 7EA gas turbines since commissioning of the plant in November 1987. Changes to the inlet air filtration system became necessary due to system limitations, a desire to reduce operational and maintenance costs, and enhance overall plant performance. Based on approximately 2 years of operational data with the latest filtration system combined with other operational experiences of more than 25 years, it is shown that implementation of the high efficiency particulate air filter system provides reduced number of crank washes, gas turbine performance improvement and significant economic benefits compared to the traditional synthetic media type filters. Reasons for improved gas turbine performance and associated economic benefits, observed via actual operational data, with use of the latest filter system are discussed in this paper.

Utility Perspective of Selecting Air Filter for Simple-Cycle, Heavy-Duty Combustion Turbines

1992 ◽  
Author(s):  
James W. Lyons ◽  
Alex Morrison
Keyword(s):  
Cost Benefit ◽  
Simple Cycle ◽  
Air Filtration ◽  
Heavy Duty ◽  
Air Filters ◽  
Air Filter ◽  
Filter System ◽  
Media Type ◽  
Air Inlet ◽  
Air Passage

The combustion turbines evaluated for this study range in size (nominal) from 80 MW to 100 MW and operate at a compression ratio between 10 and 14. Under these conditions the compressor ingests about 500,000 to 725,000 cubic feet of air per minute for its rated output. With this volume of air, even low concentrations of contaminants can result in a significant total amount of contaminants entering the unit, which may cause compressor erosion, fouling, and foreign object damage in the compressor section and cooling air passage blockage, locking of turbine blade roots, and hot corrosion or sulfidation in the turbine section. Adequate protection against the above mentioned degradation or damage due to poor air quality may be obtained by using properly designed air filters. An inadequate filter system or having no filter system results in a reduction in power and efficiency over the life of the unit and may significantly decrease the intervals between maintenance and thereby increase the cost of maintenance. Consideration should be given to adding an air inlet filter when or after the combustion turbine without air filter is overhauled to reduce future maintenance costs. This study investigates the need for an inlet air filtration system for the simple-cycle, heavy-duty combustion turbines from a cost/benefit and operation standpoint. Options for inlet air filters include a self-cleaning pulse type filter, a surface loading cartridge filter without pulse feature, and a three-stage depth loading type media type filter. Benefits are determined by estimates of improvements in performance and effects on the combustion turbine’s longevity and maintenance.

scholarly journals Effectiveness and Eco-Costs of Air Cleaners in Terms of Improving Fungal Air Pollution in Dwellings Located in Southern Poland—A Preliminary Study

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1255
Author(s):  
Ewa Brągoszewska ◽  
Magdalena Bogacka ◽  
Krzysztof Pikoń
Keyword(s):  
Air Pollution ◽  
Indoor Air ◽  
Air Pollutants ◽  
High Efficiency ◽  
Economic Cost ◽  
Airborne Fungi ◽  
Average Concentration ◽  
Indoor Environments ◽  
Air Cleaners ◽  
Indoor Air Pollutants

Epidemiological evidence shows that air pollution is responsible for several million premature deaths per year. By virtue of being responsible for these deaths, economic evidence shows that air pollution also imposes a so-called economic cost to society of several trillion dollars per year. The diseases caused by biological air pollutants are of primary global concern for both social and economic reasons, and given that people may spend more than 90% of their time in enclosed spaces, the investigation into methods to remove indoor air pollutants is of paramount importance. One of the methods to improve indoor air quality (IAQ) is to use air cleaners (ACLs) with high-efficiency particulate air filters (HEPA) that remove biological indoor air pollutants from indoor environments. This work presents the results of a study of fungal aerosol samples collected during the summer season from inside two dwellings (DG1 and DG2) before and after starting the use of ACLs. The fungal aerosol samples collected from each of the six stages of the sampler were incubated on agar plates at 26 °C, and the colony forming units (CFU) were manually counted and statistically corrected. The concentration of living airborne fungi was expressed as the CFU in the volume of air (CFU·m−3). The average concentration of fungal aerosol decreased the most when the ACLs were active for 24 min. The reduction was from 474 CFU·m−3 to 306 CFU·m−3, and from 582 CFU·m−3 to 338 CFU·m−3 in DG1 and DG2, respectively. The use of ACLs was assessed by the life cycle assessment (LCA) methodology. This study highlights the benefits of controlling biological air pollutants in order to keep occupants of buildings happy and healthy.

scholarly journals Modeling the Impact of an Indoor Air Filter on Air Pollution Exposure Reduction and Associated Mortality in Urban Delhi Household

2019 ◽  
Vol 16 (8) ◽  
pp. 1391
Author(s):  
Jiawen Liao ◽  
Wenlu Ye ◽  
Ajay Pillarisetti ◽  
Thomas F. Clasen
Keyword(s):  
Air Pollution ◽  
Indoor Air ◽  
High Efficiency ◽  
Fine Particulate Matter ◽  
Personal Exposure ◽  
Health Concern ◽  
Air Filter ◽  
Indoor Exposure ◽  
Pm2.5 Exposure ◽  
The Impact

Indoor exposure to fine particulate matter (PM2.5) is a prominent health concern. However, few studies have examined the effectiveness of long-term use of indoor air filters for reduction of PM2.5 exposure and associated decrease in adverse health impacts in urban India. We conducted 20 simulations of yearlong personal exposure to PM2.5 in urban Delhi using the National Institute of Standards and Technology’s CONTAM program (NIST, Gaithersburg, MD, USA). Simulation scenarios were developed to examine different air filter efficiencies, use schedules, and the influence of a smoker at home. We quantified associated mortality reductions with Household Air Pollution Intervention Tool (HAPIT, University of California, Berkeley, CA, USA). Without an air filter, we estimated an annual mean PM2.5 personal exposure of 103 µg/m3 (95% Confidence Interval (CI): 93, 112) and 137 µg/m3 (95% CI: 125, 149) for households without and with a smoker, respectively. All day use of a high-efficiency particle air (HEPA) filter would reduce personal PM2.5 exposure to 29 µg/m3 and 30 µg/m3, respectively. The reduced personal PM2.5 exposure from air filter use is associated with 8–37% reduction in mortality attributable to PM2.5 pollution in Delhi. The findings of this study indicate that air filter may provide significant improvements in indoor air quality and result in health benefits.

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