ABSTRACT
This paper presents an evaluation of the impact of changes in building HVAC system operation guidelines, aiming to reduce COVID-19 propagation, on building energy performance. Given the recentness and emergency nature of these responses, there is a gap in the literature addressing the energy performance impact of these new recommendations. Practical measures recommended by ASHRAE and REHVA are implemented in a computer simulation model of an existing building, created using the eQUEST program. Results show the increase of building EUI and operating cost mostly in the range of 20% to 60%. This increase is mainly due to additional: (a) space heating and cooling thermal loads, and (b) ventilation fans and pumps electricity consumption;caused by longer operation hours, increased ventilation rates and the implementation of humidity control. This research showcases the application of modelling tools in the support of public guidelines development, and it serves as an encouragement to consultants and researchers to explore methods for mitigating the impact and increasing feasibility of public health regulations. © International Building Performance Simulation Association, 2022
ABSTRACT
During the current COVID-19 pandemic, the large number of positive cases of infection has resulted in medical institutions lacking personnel to treat patients who continue to arrive. As a result of these problems, supervision and monitoring of room conditions is still lacking or even non-existent, so that the recovery process can be hampered or can facilitate the transmission of the virus to other people. It takes a device or tool that can monitor conditions and regulate the isolation room so that the temperature and humidity remain in the optimal zone so that recovery can be optimal and also reduce the risk of virus transmission. Based on this description, the author applies the concept of IoT by utilizing the IoT platform system and designing a system and tool that can monitor and regulate the COVID-19 isolation room and convey this information quickly and concisely. In addition, this study also examines how well and easily understood the system is when used by end-users by using the System Usability Scale or SUS as its usability testing method. The results obtained from this study are that the system and equipment function properly, the automation system and the method used are able to mitigate changes in temperature and humidity in the isolation room, and through the SUS method, the level of usability for end-users is deemed quite sufficient. © 2022 IEEE.
ABSTRACT
The COVID-19 pandemic has influenced many aspects of human life, including working environments. Some research finds that there is a tendency to the increase of energy and CO2 emissions of large office buildings in developed countries, such as US and Europe's top five economics, post-pandemic. Therefore, advanced heating, ventilation and air-conditioning (HVAC) technology that can reduce energy consumption in the building sector will yield a significant impact on the total national energy consumption. Many buildings equipped with conventional control in their HVAC control systems, such as PI or PID controls. Such controllers have drawbacks like unable to handle cross-coupling nature and constraints in a HVAC system. Conversely, model predictive control (MPC) - which belongs to advanced control - has the advantages when dealing with the system with constraints and uncertainties as it can take into account them in its optimization control problem formulation. This paper derived mathematically an industrial HVAC system based on Hammerstein-bilinear model - a model consists of a static nonlinearity followed by a dynamic bilinear subsystem. The obtained linear output-error (OE) models are subsequently used as plant models in the MPC design. The MPC controller performance is quite superior and proven to be able to meet the desired control objective (keeping the zone temperature in range of . In addition, the MPC controller gives more economic energy consumption (about save) than the PI one both for temperature and humidity control loop. © 2022 ACM.
ABSTRACT
COVID-19 can be spread through the air, caused by inhaling smaller droplets1 containing SARS-CoV-2 in an indoor environment. In particular, both people with symptoms and people without symptoms make many small droplets and respiratory droplets when they breathe, sneeze, cough, or speak. When these tiny droplets are exposed to the air around them, they can react with the particles (PM) and stay in the air for a long time. The survival period depends on various conditions, including the type of surface, temperature, and relative humidity. The ventilation system is one way to solve this problem. This research makes a significant contribution to the development of intelligent ventilation systems utilizing the Internet of Things (IoT) and decision tree algorithms. The function of this system is to get a clean room environment from viruses by spraying disinfectant automatically and controlling the temperature and humidity of the air. Based on the results of this study, the system is able to control and categorize room conditions based on temperature and humidity factors. The classification value using the C4.5 decision tree algorithm is 92.33% with an average temperature and humidity value of 25oC and 49%. © 2022 IEEE.
ABSTRACT
New Zealand and many countries gained heightened awareness of indoor air quality (IAQ) issues, and increased investment, according to the World Health Organization (WHO) guidelines, to improve their IAQ and reduce air pollution in commercial and residential buildings. Additionally, some countries have introduced new standards for indoor environments, such as the New Zealand "healthy homes” standard. At the same time, COVID-19 pandemic forced many people to spend much more time in indoor spaces, due to stay-at-home, or lockdown orders by governments. This increased attention on other aspects of indoor environmental quality, such as occupants' satisfaction with thermal comfort parameters, presents an additional parameter for research and in the development of standards. From a medical perspectives, infectious respiratory diseases, such as influenza or COVID-19, are transmitted by airborne droplets. In this work, we assess a Polyester Filter and UV light (PFUV) dehumidifier device performance in an office with two occupants (one uninfected and the other one infected with a disease with airborne transmission using computational fluid dynamics (CFD) approach. Two positions for locating the PFUV dehumidifier in an office with a scenario in which one person is exhaling infected air and the other occupant must inhale and exhale from the shared air. The CFD model illustrated the best position of the device to distribute the air velocity contours. Further, based on the CFD model which was validated via the IAQ and comfort kit (Testo 400) thermal comfort analysis showed that the room is slightly cold. Copyright © 2022 by ASME.
ABSTRACT
As the amount of ventilation required in buildings has increased to prevent the spread of COVID-19, the inflow of high humidity outside air in summer has increased the processing rate of latent heat loads as well as sensible heat loads. Accordingly, the ability to handle the latent heat load with low energy consumption has become important in order to maintain a comfortable indoor environment. In this study, a humidity control device composed of a desiccant rotor was designed and manufactured, and performance experiments were performed. Using an empirical formula obtained through experiments, a thermal environment simulation was conducted for a school classroom. Furthermore, a temperature-humidity control device that combines a desiccant rotor and heat pump was proposed, and the performance and energy consumption were analyzed by comparing it with the existing heat pump design. With conventional temperature control method using a heat pump, the average indoor relative humidity values in August were 65.7 %, which exceeds the set relative humidity range of 50 +/- 5 %. On the other hand, when using the temperature-humidity control device, the average indoor relative humidity values in August was 50.2 %, a more comfortable indoor environment than when using a conventional method. In addition, the energy consumption was reduced by 3 % compared to existing heat pump design.
ABSTRACT
This work presents the development of an individual protection device, a smart and active ventilated face shield that can also incorporate an air filtering system. The device can work with the front shield or just with the ventilation structure. The system was produced by additive manufacturing technology, based on a chassis that incorporates an electronic control unit, a rechargeable battery, a fan, and a humidity/temperature sensor. The performed system tests showed that the forced ventilation system prevents fogging even in the most adverse situations and increases user comfort when it is used simultaneously with an individual protective face mask, due to the air flow generated by the integrated fan. The filtered ventilated air guarantees the user's safety. Results also show that, with or without the front visor, the equipment prevents fogging, both on the face shield and glasses for users who wear them. The forced air flow promotes isolation of the breathing zone, decreasing the contact with potentially contaminated aerosols, thus reducing the risk of contagion. © 2022 IEEE.
ABSTRACT
With the increasing requirements for fresh air supply in buildings after the COVID-19 pandemic and the rising energy demand from buildings, there has been an increased emphasis on passive cooling techniques such as natural ventilation. While natural ventilation devices such as windcatchers can be a sustainable and low-cost solution to remove indoor pollutants and improve indoor air quality, it is not as reliable as mechanical systems. Integration with low-energy cooling, heating or heat recovery technologies is necessary for operation in unfavourable outdoor conditions. In this research, a novel dual-channel windcatcher design consisting of a rotary wind scoop and a chimney was proposed to provide a fresh air supply irrespective of the wind direction. The dual-channel design allows for passive cooling, dehumidification and heat recovery technology integration to enhance its thermal performance. In this design, the positions of the supply and return duct are "fixed” or would not change under changing wind directions. An open wind tunnel and test room were employed to experimentally evaluate the ventilation performance of the proposed windcatcher prototype. A Computational Fluid Dynamic (CFD) model was developed and validated to further evaluate the system's ventilation performance. The results confirmed that the system could supply sufficient fresh air and exhaust stale air under changing wind directions. The ventilation rate of the rotary scoop windcatcher was higher than that of a conventional 8-sided multidirectional windcatcher of the same size. © 2023 The Author(s)
ABSTRACT
This work presents the development of an individual protection device, a smart and active ventilated face shield that can also incorporate an air filtering system. The device can work with the front shield or just with the ventilation structure. The system was produced by additive manufacturing technology, based on a chassis that incorporates an electronic control unit, a rechargeable battery, a fan, and a humidity/temperature sensor. The performed system tests showed that the forced ventilation system prevents fogging even in the most adverse situations and increases user comfort when it is used simultaneously with an individual protective face mask, due to the air flow generated by the integrated fan. The filtered ventilated air guarantees the user's safety. Results also show that, with or without the front visor, the equipment prevents fogging, both on the face shield and glasses for users who wear them. The forced air flow promotes isolation of the breathing zone, decreasing the contact with potentially contaminated aerosols, thus reducing the risk of contagion. © 2022 IEEE.
ABSTRACT
During the Covid-19 period, respitory rate monitoring is the main way to know respiratory conditions. However, the use of masks can cause stuffiness for the wearer. Therefore, a smart mask that respiratory rate monitoring was designed based on the difference in the temperature of the breathing, which was read by the LM35 temperature sensor and displayed in the blynk application on the Smartphone. The system is also equipped with a buzzer that will give a warning when breathing conditions are abnormal. In addition to the monitoring system, there is also a humidity control that is the of an exhaust fan actuator to maintain the humidity inside the mask that always adjusts to the setpoint. From the sensor performance test, it was found that the mean error of the LM35 temperature sensors was 3.14%, the DHT11 temperature sensors was 2.7% and the mean error of the DHT11 humidity sensor was 4%. In the respiratory rate measurement prototype, the mean error was 1.87%, and the accuracy of 98.1 %. Meanwhile, testing the fan response to the 84% RH setpoint, the Error Steady State (ess) was 0% and the Maximum Overshoot (Mp) was 1.19%, which means it is still below the 2% allowed tolerance value. Thus, the control system to be in a steady state. © 2021 IEEE.
ABSTRACT
The era of sudden eruption of the COVID-19 infection, since January 2020, drew much attention of the world due to its impact turning into a large-scale issue for all the countries, and thus an alarm of Corona Pandemic was declared all across, by February 2020. The same adverse effect was sensed by the middle of March 2020 in India too, when the declaration of total lockdown in the country was left as the only option which was implemented on 24th March 2020, by the Government of India. Such sudden development of hopes and apprehensions in the minds of all in India, sparked a thought of reducing the scope of spread of and infection due to this deadly virus to a considerable amount, mainly in the process of the exchange of various kinds of reading materials including books, by the students, in the post COVID-19 scenario.As a preparatory measure, this thought got converted into the development of a book sanitizer to be housed in the Library of the North-Eastern Hill University, Shillong, on the initiatives shown by the Dy. Librarian, which led the authors, in My 2020 to take up the project of developing an appropriate device The objective was to generate a device which sanitizes the books and other hard form reading materials maintained in the Library and remains free from contamination of the Corona virus to the maximum. For that, a book sanitizing machine is developed in a span of nearly three months. The device, named as Automated Book Sanitizing Composite Machine (ABSCoM) works on the technique based on the principle of UV-ray irradiation, integrated with the thermal exposure of the books in a controlled manner. A special feature of automation is employed to monitor the parameters of critical temperature set for the exposure at which the SARS virus is reported to get destroyed. Additionally, the time of thermal exposure of book and the relative humidity level of each book in the stack of books loaded in the device for sanitization is also monitored through microcontroller system and a bell alarming component. Sufficient care for maintaining the quality of the book post sanitization, as original, is the additional key factor in developing this device. © 2021 IEEE.
ABSTRACT
Food for cities is traditionally cultivated on a large scale on farmland then transported to the city where it is consumed. The COVID-19 pandemic has in some places disrupted transportation systems, resulting in severe food shortages in some metropolitan areas. Growing plants on a terrace or other sunny areas could provide urban residents with some portion of their food supply and reduce food transportation distance. In this paper, we propose a simple, low-cost, and durable Internet of Things (IoT)-based system for cultivating short-duration vegetables, flowers, and fruits on urban terraces with minimal user attention. The proposed system is capable of monitoring environmental parameters (temperature and humidity) and controlling soil elements such as soil moisture and soil nutrients. The system can be deployed with pre-existing Wi-Fi infrastructure in the farmer's home with or without an internet connection. The proposed terrace farming system is easy to install, scalable, robust in terms of data security, and developed on open-source platforms with cost-effective hardware components. © 2021 IEEE.
ABSTRACT
The emergence of the SARS-CoV-2 pandemic and airborne particulate matter (PM) pollution has led to remarkably high demand for face masks. However, conventional respirators are intended for single use and made from nondegradable materials, causing serious concern for a plastic-waste environmental crisis. Furthermore, these facemasks are weakened in humid conditions and difficult to decontaminate. Herein, a reusable, self-sustaining, highly effective, and humidity-resistant air filtration membrane with excellent particle-removal efficiency is reported, based on highly controllable and stable piezoelectric electrospun poly (l-lactic acid) (PLLA) nanofibers. The PLLA filter possesses a high filtration efficiency (>99% for PM 2.5 and >91% for PM 1.0) while providing a favorable pressure drop (≈91 Pa at normal breathing rate) for human breathing due to the piezoelectric charge naturally activated by respiration through the mask. The filter has a long, stable filtration performance and good humidity resistance, demonstrated by a minimal declination in the filtration performance of the nanofiber membrane after moisture exposure. The PLLA filter is reusable via common sterilization tools (i.e., an ultrasonic cleaning bath, autoclave, or microwave). Moreover, a prototype of a completely biodegradable PLLA nanofiber-based facemask is fabricated and shown to decompose within 5 weeks in an accelerated degradation environment. © 2022 Wiley-VCH GmbH
ABSTRACT
Newly born babies are very sensitive to rough environments, especially in Pakistan. The dust and temperature issues here can be life threatening. Due to these issues, a baby incubator is made that can provide the same temperature and environmental conditions as a mother's womb does, as well as it monitors the baby's medical conditions such as heart beat, skin temperature, internal temperature, etc. Due to COVID-19 pandemic, healthcare has become a major concern for everyone. Being physically present with the patients has become a huge problem for doctors. In such cases, implementing IoT with hospital equipment such as a Baby Incubator, has become one of the main goals for us. Providing an app that can track the baby's condition remotely will prove to be very fruitful. Our main goal is to make a smart baby incubator that can detect baby's condition and in case anything goes wrong, the system can trip itself so that the conditions can return to a normal state. We will integrate it with IoT and a mobile app so that doctors can check the baby's condition remotely. It can be easy to think of an incubator as just a bed for a sick baby, but it's so much more than a place for sleeping. An incubator is designed with such techniques and care that it can provide a safe and sound atmosphere for a newborn baby to rest until its vital organs are still in a development stage. When we compare our incubator to a simple hospital bed, an incubator will provide a completely controlled environment as well as the required amount of oxygen levels, perfect light exposure and humidity matches with the mother's womb. In addition to climate control, an incubator offers protection from other harmful factors that can damage a baby such as allergens, loud noises, bacteria and viruses, etc. An incubator's ability to control humidity also allows it to protect a baby's skin from losing too much water and becoming brittle or cracking. An incubator can include equipment to track a range of things including a baby's temperature and heart rate. This monitoring allows nurses and doctors to constantly track a baby's health status. © 2021 IEEE.
ABSTRACT
The spread of the coronavirus SARS-CoV-2 affects the health of people and the economy worldwide. As air transmits the virus, heating, ventilation and air-conditioning (HVAC) systems in buildings, enclosed spaces and public transport play a significant role in limiting the transmission of airborne pathogens at the expenses of increased energy consumption and possibly reduced thermal comfort. On the other hand, liquid desiccant technology could be adopted as an air scrubber to increase indoor air quality and inactivate pathogens through temperature and humidity control, making them less favourable to the growth, proliferation and infectivity of microorganisms. The objectives of this study are to review the role of HVAC in airborne viral transmission, estimate its energy penalty associated with the adoption of HVAC for transmission reduction and understand the potential of liquid desiccant technology. Factors affecting the inactivation of pathogens by liquid desiccant solutions and possible modifications to increase their heat and mass transfer and sanitising characteristics are also described, followed by an economic evaluation. It is concluded that the liquid desiccant technology could be beneficial in buildings (requiring humidity control or moisture removal in particular when viruses are likely to present) or in high-footfall enclosed spaces (during virus outbreaks).