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1.
CFD Letters ; 15(1):26-38, 2023.
Article in English | Scopus | ID: covidwho-2218190

ABSTRACT

Air quality plays a significant role during the coronavirus pandemic. Air acts as a spreading media as well as a control measure for infection in polluted spaces. Insufficient ventilation around the building may lead to a rise of pollutants carrying the virus. One way to improve ventilation is by increasing the air change rate. This study investigates the air change rate effectiveness in reducing droplets spreading in a classroom. Cases with various layouts of inlet and outlet vents are considered, and the spread of droplets is studied. The airflow analysis shows the impact of the different ventilation layout configurations. The results show that the CFD model simulation indicates an optimum ventilation configuration to decrease the droplet spread. The discrete phase model results also determine the trajectory of droplets spread along the classroom. CFD results show that in the selected configuration, a significant number of droplets are expelled to the outside and reduce their concentration inside the classroom. © 2023, Penerbit Akademia Baru. All rights reserved.

2.
Tanaffos ; 20(3): 240-245, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-2169156

ABSTRACT

Background: Ventilation system besides other prevention strategies such as surface disinfecting and personal protective equipment (PPE) decrease the risk of coronavirus disease 2019 (COVID-19) infection. This study aimed to examine the ventilation system of an intensive care unit (ICU) in a hospital in Tehran, Iran to evaluate the potency of heating, ventilation, and air conditioning system (HVAC) for COVID-19 spread. Materials and Methods: Contamination of air turnover caves was evaluated in supplier diffuser and extractor grills of negative pressure HVAC by ten samples. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the samples was evaluated by the real time reverse transcription-polymerase chain reaction (PCR). Moreover, air conditioning and sick building syndrome (SBS) was assessed according to MM040EA questioning from health care workers. Results: In the health care workers, respiratory effects were more prevalent compared to other signs. Despite suitable air conditioning, this study highlighted carrier potency of ICU workers for SARS-COV-2. Conclusion: According to our results, although the HVAC of ICU ward had an appropriate air movement, it was not safe enough for health care workers.

3.
Journal of Advanced Research in Applied Sciences and Engineering Technology ; 29(1):198-206, 2022.
Article in English | Scopus | ID: covidwho-2206478

ABSTRACT

Since 2019, the Coronavirus infection has substantially impacted the worldwide ecosystem. This disease has apparently become airborne and has spread globally. Most daily activities have been curtailed to prevent the spread of the disease. Several measures have been devised by the World Health Organization to control the transmission of disease among humans. However, interior spaces are also crucial because individuals spend most of their time inside. To improve the interior living environment, it is necessary to develop a way to prevent the spread of airborne diseases. To obtain the desired level of efficiency and the requisite level of health for people to stay indoors, it is essential to install an efficient ventilation system. To avoid the transmission of airborne infections in confined areas, the purpose of this work is to examine the impact of the filtering mechanism in a controlled environment provided by Heating, Ventilation, and Air Conditioning (HVAC) systems. According to the study, ventilation, along with MERV13 or above recirculating filters, for instance, must be used (High-Efficiency Particulate Air) This criterion can be met with HEPA or a combination of outside air, filtration, and air-cleaning technology. To reduce the transmission of airborne diseases, the outcome of the study will result in a more effective installation of the mechanism of HVAC systems in interior environments. © 2022, Penerbit Akademia Baru. All rights reserved.

4.
Tem Journal-Technology Education Management Informatics ; 11(4):1563-1568, 2022.
Article in English | Web of Science | ID: covidwho-2204564

ABSTRACT

People spend much of their lives indoors, so air quality is particularly important to their health, ability to work, and well-being. The COVID-19 pandemic has heightened people's awareness of the importance of maintaining high indoor air quality. Such an emergency has underscored the need for adequate heating, ventilation and air conditioning systems that can provide a good indoor air quality, especially ventilation systems as important players in preventing and reducing the risk of airborne infections. In this paper, we review natural and mechanical ventilation and their roles in dealing with coronavirus, focusing on key factors for healthy indoor air. Two pillars are critical for ventilation: increased air exchange rate and air filtration in ventilation systems.

5.
Antimicrobial Stewardship and Healthcare Epidemiology ; 2(S1):s85, 2022.
Article in English | ProQuest Central | ID: covidwho-2184988

ABSTRACT

Background: High-efficiency particulate air (HEPA) filters are currently recommended when using recirculated air to eliminate the risk of pathogen transmission such as SARS-CoV-2 from one patient care area to the next. We tested the efficacy of lower-grade air filters in eliminating airborne virus transmission. Methods: We conducted an experiment in 2 adjacent exam rooms in an unoccupied hospital emergency unit. The HVAC system contained a 15,000-cubic-feet-per-minute rooftop air handler. All outside air and exhaust dampers were closed during the trial (full air recirculation). We conducted experiments in 3 tests arms with varying grades of MERV filters (AAF Flanders, Louisville, KY): (1) control without filters, (2) MERV8+14 filters, and (3) MERV8+16 filters. We repeated 20-minute virus challenge runs 3 times per test arm. Live attenuated influenza vaccine (2 mL LAIV, FluMist Quadrivalent 2020/21, AstraZeneca, Wilmington, DE), was aerosolized into the HVAC system via a commercial nebulizer. Air was sampled using 3 six-stage Andersen air samplers placed in the center of the adjacent room. Environmental particle counts were collected using a particle counter (PEC-PCO-1, PCE Americas). Results: Concentrations of viral RNA were determined by qPCR, and viral concentrations (vg/mL) in each stage of each arm were compared directly. Pairwise comparisons of the virus and particle burdens across each stage of each test arm were made using a general linear model. LAIV was detected in the control arm at a virus burden of 2,277 vg/mL, indicating a >6.5 log reduction of the virus released in the HVAC system (8.8×109 total vg). In the second arm, the MERV8+MERV14 filters demonstrated in a 13-fold decrease in viral burden compared to the control arm (mean virus burden: 169 vg/mL, p Our study demonstrates that viral containing particles can be transported via a hospital HVAC system from one patient room to the next. Considering the decrease in detectable virus within the HVAC system, the combination of MERV8+MERV16 filters reduced the virus burden reaching an adjacent room to levels well below the human infectious dosages for influenza and other highly infective viruses. Conclusions: Our findings indicate that MERV8+MERV16 filters provide protection against virus transmission through HVAC systems and are a cost-conscious alternative to HEPA filters.Funding: NoneDisclosures: None

6.
ASHRAE Journal ; 64(12):6, 2022.
Article in English | ProQuest Central | ID: covidwho-2167538

ABSTRACT

Because of the impact that COVID-19 is having on conferences, please check the conference's website for the most up-to-date information. 2023 JANUARY ABMA Annual Meeting, Jan. 13 - 16, Carlsbad, Calif. Contact the Indoor Air Quality Association at 844-802-4103, info@iaqa.org or https://annualmeeting.iaqa.org MARCH HVAC Cold Climate Conference 2023, March 6 - 8, Anchorage, Alaska. Contact the American Council for an Energy-Efficient Economy at 202-507-4000 or www.aceee.org/2023-hot-water-forum IIAR Natural Refrigeration Conference & Heavy Equipment Expo, March 12 - 15, Long Beach, Calif.

7.
Appl Energy ; 313: 118848, 2022 May 01.
Article in English | MEDLINE | ID: covidwho-2158437

ABSTRACT

This paper proposes a time-series stochastic socioeconomic model for analyzing the impact of the pandemic on the regulated distribution electricity market. The proposed methodology combines the optimized tariff model (socioeconomic market model) and the random walk concept (risk assessment technique) to ensure robustness/accuracy. The model enables both a past and future analysis of the impact of the pandemic, which is essential to prepare regulatory agencies beforehand and allow enough time for the development of efficient public policies. By applying it to six Brazilian concession areas, results demonstrate that consumers have been/will be heavily affected in general, mainly due to the high electricity tariffs that took place with the pandemic, overcoming the natural trend of the market. In contrast, the model demonstrates that the pandemic did not/will not significantly harm power distribution companies in general, mainly due to the loan granted by the regulator agency, named COVID-account. Socioeconomic welfare losses averaging 500 (MR$/month) are estimated for the equivalent concession area, i.e., the sum of the six analyzed concession areas. Furthermore, this paper proposes a stochastic optimization problem to mitigate the impact of the pandemic on the electricity market over time, considering the interests of consumers, power distribution companies, and the government. Results demonstrate that it is successful as the tariffs provided by the algorithm compensate for the reduction in demand while increasing the socioeconomic welfare of the market.

8.
Applied Biosafety ; 27(4):225-230, 2022.
Article in English | Web of Science | ID: covidwho-2160876

ABSTRACT

Introduction: The global SARS-CoV-2 pandemic ushered in a new way of life in a short time, with many lasting impacts that have yet to be fully realized. This pandemic threat landscape resulted in massive efforts to increase safety, minimize person-to-person transmission, and rethink how society approaches personal and collective health issues. The buildings and environments in which we live, work, and learn now became environments that pose new risks. As a result, many institutions began asking what improvements could be made to those environments to reduce the spread of infection of SARS-CoV-2 and other infectious diseases.Methods: The authors conducted a review of past projects and emerging technologies to evaluate which applications in containment laboratories could represent an example of how engineering controls can improve safety by protecting the workers inside the laboratories as well as the public interfacing the laboratories.Discussion: Engineering controls, technology, and safety systems are hallmarks of modern containment laboratories that may provide some context into extrapolating these elements into non-laboratory environments, providing there is coordination with a risk assessment methodology. In this study, the authors explore new technologies proposed for controlling SARS-CoV-2 in heating, ventilation, and air conditioning systems, and potential impacts to the operations and maintenance of those systems.

9.
International Journal of Air-Conditioning and Refrigeration ; 28(2), 2020.
Article in English | ProQuest Central | ID: covidwho-2138152

ABSTRACT

Recent concerns raised by the World Health Organization over the Coronavirus raised a worldwide reaction. Governments are racing to contain and stop the Coronavirus from reaching an epidemic/pandemic status. This research presents a way in tracking such a virus or any contagious germ capable of transferring through air specifically where such a transfer can be assisted by a mechanical room ventilation system. Tracking the spread of such a virus is a complicated process, as they can exist in a variety of forms, shapes, sizes, and can change with time. However, a beginning has to be made at some point. Assumptions had to be made based on published scientific data, and standards. The tracking of airborne viruses was carried out on the following assumption (for illustrative purposes);one person with one sneeze in a period of 600 s. The presence of viruses was tracked with curves plotted indicating how long it could take to remove the sneezed viruses from the mechanically ventilated room space. Results gave an indication of what time span is required to remove airborne viruses. Thus, we propose the following: (a) utilizing CFD software as a possible tool in optimizing a mechanical ventilation system in removing contagious viruses. This will track the dispersion of viruses and their removal. The numerical solution revealed that with one typical adult human sneeze, it can take approximately 640 s to reduce an average sneeze of 20,000 droplets to a fifth;(b) upscaling the status of human comfort to a “must have” with regards to the 50% relative humidity, and the use of Ultraviolet germicidal irradiation (UVGI) air disinfection in an epidemic/pandemic condition. A recommendation can be presented to the local authorities of jurisdiction in enforcing the above proposals partially/fully as seen fit as “prevention is better than cure”. This will preclude the spread of highly infectious viruses in mechanically ventilated buildings.

10.
3rd International Conference on Intelligent Computing, Instrumentation and Control Technologies, ICICICT 2022 ; : 1534-1539, 2022.
Article in English | Scopus | ID: covidwho-2136269

ABSTRACT

An IoT-based system for monitoring the quality of the air within a building, which includes a "Smart-Air"air quality sensor on a web server. IoT and cloud storage are used to evaluate the quality of the air at any time and from any place. Smart-Air is a product of the Internet of Things (IoT), a device that uses LTE to broadcast real-time data on air quality to a web server. Today, air pollution is a leading cause of preventable mortality and disease across the world. Pollution has become a major concern all around the globe. The discharge of chemicals or unfriendly compounds has a devastating impact on human, animal, and plant life. This is referred to as pollution. Many studies have been conducted on different air purification techniques because of this. Air purifiers that utilize HEPA filters, activated carbon, and UV light are discussed in this paper. The water and chemicals that an air purifier sprays into the air will spread out contaminants. © 2022 IEEE.

11.
Facilities ; 2022.
Article in English | Web of Science | ID: covidwho-2121253

ABSTRACT

Purpose The purpose of this study was to examine how data from the World Health Organization, United States Environmental Protection Agency and Center for Disease Control have evolved with relation to engineering controls for heating, ventilation and air-conditioning (HVAC) systems to mitigate the spread of spread of aerosols (specifically related to the COVID-19 pandemic) in occupied buildings. Design/methodology/approach A document analysis of the pandemic-focused position documents from the aforementioned public health agencies and national HVAC authorities was performed. This review targeted a range of evidence from recommendations, best practices, codes and regulations and peer-reviewed publications and evaluated how they cumulatively evolved over time. Data was compared between 2020 and 2021. Findings This research found that core information provided early in the pandemic (i.e. early 2020) for engineering controls in building HVAC systems did not vary greatly as knowledge of the pandemic evolved (i.e. in June of 2021). This indicates that regulating agencies had a good, early understanding of how airborne viruses spread through building ventilation systems. The largest evolution in knowledge came from the broader acceptance of building ventilation as a transmission route and the increase in publications and ease of access to the information for the general public over time. Originality/value The promotion of the proposed controls for ventilation in buildings, as outlined in this paper, is another step toward reducing the spread of COVID-19 and future aerosol spread viruses by means of ventilation.

12.
ASHRAE Journal ; 64(8):10-12,14,16, 2022.
Article in English | ProQuest Central | ID: covidwho-2112132

ABSTRACT

In a speech, ASHRAE president Farooq Mehboob discusses various issues including the importance of forming relationships, gaining knowledge and embracing change. He also highlights the hostilities that led to the breakup of Pakistan into two countries: East Pakistan became Bangladesh, and West Pakistan became modern-day Pakistan.

13.
ASHRAE Journal ; 64(9):28-30, 2022.
Article in English | ProQuest Central | ID: covidwho-2112097

ABSTRACT

Another continuous maintenance cycle for ANSI/ASHRAE Standard 62.1 has concluded, and the keen observer will have already noticed one of the changes made in the 2022 edition of the standard. Despite the conditions created by the COVID-19 pandemic, the committee has continued to meet over the past two years, more often in web conferences than in person, to consider continuous maintenance proposals and interpretation requests and to discuss issues related to ventilation and indoor air quality. The addenda that have been adopted to the 2019 edition of that standard generally fall into three categories: clarifications, harmonization and improved procedures. Work was also begun on mandatory air density corrections, further development of humidity control requirements and addressing future extreme events, but this work was not completed in time for inclusion in the 2022 edition of the standard.

14.
ASHRAE Journal ; 64(11):6, 2022.
Article in English | ProQuest Central | ID: covidwho-2112090

ABSTRACT

Robert Guery, Life MemberASHRAE, Ebmatingen, Switzerland * From July's "Confessions of a Control Freak," by Andy Pearson, Ph.D., C.Eng., Fellow ASHRAE, regarding cooling systems with multiple capacity stages that "hunt," in addition to increasing the stage delay time, one should also consider the cooling demand side. MemberASHRAE, Brisbane, Australia Airborne Disease Transmission Risk We read "Airborne Disease Transmission Risk and Energy Impact of HVAC Mitigation Strategies" by Michael J. Risbeck, Ph.D., et al., from May with great interest, and we agree that ventilation is a costly source of achieving adequate equivalent outdoor air (EOA) supply. [...]the cost of operating ventilation systems for reducing infection risk is much lower than the cost of taking care of a large number of infected patients.1 Overloading the health-care system is a painful lesson learned in many places.

15.
ASHRAE Journal ; 64(11):8, 2022.
Article in English | ProQuest Central | ID: covidwho-2112088

ABSTRACT

Because of the impact that COVID-19 is having on conferences, please check the conference's website for the most up-to-date information. DECEMBER HARDI Annual Conference, Dec, 3-6, Houston, Contact Heating Air-conditioning & Refrigeration Distributors International at 888-253-2128, hardimail@hardinet.org or https://hardinet.org/events Buildings XV Conference, Dec, 5-8, Clearwater Beach, Fla, Contact ASHRAE at 800-527-4723, meetings@ashrae.org or www.ashrae.org/buildingsxv International Conference on Building Ventilation and Air Conditioning, Dec. 9-10, New York, N.Y. Contact organizers at https://tinyurl.com/ICBVAC22 2023 JANUARY ABMA Annual Meeting, Jan. 13-16, Carlsbad, Calif. Contact the American Council for an Energy-Efficient Economy at 202-507-4000 or www.aceee.org/2023-hot-water-forum IIAR Natural Refrigeration Conference & Heavy Equipment Expo, March 12-15, Long Beach, Calif.

16.
J Occup Environ Hyg ; : 1-22, 2022 Oct 18.
Article in English | MEDLINE | ID: covidwho-2077490

ABSTRACT

A series of experiments in stationary and moving passenger railcars was conducted to measure the removal rates of particles in the size ranges of SARS-CoV-2 viral aerosols, and the air changes per hour provided by the existing and modified air handling systems. The effect of ventilation and air filtration systems on removal rates and their effects on estimated probability (i.e., risk) of infection was evaluated in a range of representative conditions: (1) for two different ratios of recirculated air (RA) to outdoor air (OA) (90:10 RA:OA and 67:33 RA:OA); (2) using minimum efficiency reporting value (MERV) filters with standard (MERV-8) and increased (MERV-13) filtration ratings; and (3) in the presence and absence of a portable high-efficiency particulate-air (HEPA) room air purifier system operated at clean air delivery rate (CADR) of 150 and 550 cfm. The higher efficiency MERV-13 filters significantly increased particle removal rates on average by 3.8 to 8.4 hr-1 across particle sizes ranging from 0.3 to 10 µm (p < 0.01) compared to MERV-8 filters. The different RA:OA ratios and use of a portable HEPA air purifier system had little effect on particle removal rates. MERV-13 filters reduced the estimated probability of infection by 42% compared to MERV-8 filters. Use of a HEPA-air purifier with a MERV-13 filter causes a 50% reduction in estimated probability of infection. Upgrading the efficiency of HVAC filters from MERV-8 to MERV-13 in public transit vehicles is the most effective exposure control method resulting in a clear reduction in the removal rates of aerosol particles and the estimated probability of infection.

17.
20th International Conference on Ship and Maritime Research, NAV 2022 ; 6:610-621, 2022.
Article in English | Scopus | ID: covidwho-2054924

ABSTRACT

The actual, global pandemic situation has dramatically involved every aspect of our lives. This also greatly affected the cruise ship industry. At first, cruise companies tried to face the problem by adapting existing ships at the situation, with no time to rethink completely their project. The opinion of scientists, architects and field experts highlighted the need to devise a new way to design cruise ships, considering passenger management, marketing and medical aspects. Particular attention must be paid to public areas, where individuals would be most vulnerable to airborne transmission. The sanitizing operations have now to follow even stricter operational protocols than in the past. A constant update monitoring of the passenger flows through the so-called smart technologies would allow, when dealing with a suspected case, to trace a timeline of its activities on board and, therefore, to avoid the rise of an outbreak. An implementation of the overall efficiency of vertical connections (which helps the management of potentially contaminated waste) and on-board medical spaces such as the hospital and the pharmacy shall be advised. From an anthropological point of view, it is essential to consider in more depth issues such as social distancing and the possibility of permanently decreasing the number of passengers, in favour of safety and on-board liveability. In the post COVID-19 era, the cruise ship can become a 'health bubble', a microcosm where people can enjoy an even more rewarding and safe experience. © 2022 The authors and IOS Press. All rights reserved.

18.
20th International Conference on Ship and Maritime Research, NAV 2022 ; 6:597-609, 2022.
Article in English | Scopus | ID: covidwho-2054923

ABSTRACT

But this coronavirus has forced us into a new framework, within which we move without any ease: everything has new ways, everything appears as never seen, it's like finding yourself in an uncharted territory.. ' (G. Arma, 2020) With these words Gennaro Arma, Captain of the Diamond Princess cruise ship, describes the very first moments following the detection of what would become the first recorded outbreak of Covid-19 outside of China. It occurred during a roundtrip cruise which departed from Yokohama port, in Japan, on 20 January 2020. Among the 3,700 people on board, more than 700 tested positive for the virus, 14 of whom died during hospitalization. A situation which was faced without the support of emergency protocols that contemplated a modus operandi to follow. The ship constituted a confined control volume which allowed to analyze the main routes of virus propagation that mainly occur through direct contact between individuals, indirect one via contaminated objects and surfaces (also referred to as fomites) and airborne transmission. This has greatly affected the overall design paradigm, especially concerning the safety levels to be assured on board. The paper is going to analyze these focal points, starting from a possible implementation of HVAC system. It comes after an extensive study of the air flow circulation, as well as the application of filtering and purifications solutions, considering ship age and ventilation type, assessing the possibility of isolating those sectors of the plant acting on some areas dedicated to the management of emergency situations. Synoptically, there will be an extensive analysis related to the different surface types present on board and possible design interventions (i.e. smart materials). The Diamond Princess experience represents the prime mover aimed at the world of scientific research at the formulation of design guidelines applicable to the world of cruise ships and, consequently, in the civil architecture field. The outcome results have helped to build a transversal, holistic know-how, thanks to which it will be possible to control the occurrence of future pandemic episodes. © 2022 The authors and IOS Press. All rights reserved.

19.
ASHRAE Journal ; 64(5):12-16,18-20,22,24-25, 2022.
Article in English | ProQuest Central | ID: covidwho-2046543

ABSTRACT

Significant emphasis has been placed on enhancing building HVAC systems to be more energy-efficient in recent decades. Often, these measures include reducing ventilation rates and overall airflows to achieve corresponding energy reduction. However, the COVID-19 pandemic caused an examination of how HVAC systems may help reduce the risk of airborne transmission of respiratory diseases via infectious aerosols. This new goal of infection risk mitigation often leads to the opposite recommendation-that outdoor air ventilation be increased,1 to the detriment of energy efficiency.2,3

20.
Sustainable Energy Technologies and Assessments ; 53:102776, 2022.
Article in English | ScienceDirect | ID: covidwho-2042134

ABSTRACT

Air conditioning (AC) systems for tropical countries like India account for sixty percent of the total energy needs of a building. With the onset of COVID-19, the increase of fresh air ventilation rate has been recommended by various guidelines for indoor spaces which increase the load on the AC system. The present study attempts to reduce this burden through retrofitting a phase change material (PCM) embedded pin fin heat exchanger into an air-conditioning system. The heat exchanger is designed to cater to the peak load fluctuations for cities in three hot climatic zones of India, viz., Jaisalmer, Kolkata, and Delhi. Dodecanol with a melting temperature of 24 °C, is chosen as the appropriate PCM material for these locations. The optimal pin fin diameters are estimated through an entropy generation minimization analysis for the three locations. A heat transfer analysis of the PCM embedded heat exchanger is further presented through an analytical approach to estimate the PCM mass requirement and energy savings potential. The masses of the PCM estimated for Jaisalmer, Kolkata, and Delhi are 11.36 kg, 22.42 kg, and 19.35 kg, respectively for their respective peak load fluctuations of 0.25 kW, 0.28 kW and 0.48 kW. Energy savings of up to 4.7 % for Delhi, 2 % for Kolkata, and 2.75 % for Jaisalmer are identified with the PCM embedded heat exchanger incorporation. The results show the potential of such PCM thermal storage in reducing the peak energy demands of buildings amidst various environmental and health concerns.

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