ABSTRACT
The COVID-19 pandemic has underscored the need for effective ventilation control in public buildings. This study develops and evaluates a smart ventilation control algorithm (SIREN) that dynamically adjusts zone and system-level HVAC operation to maintain an acceptable COVID-19 infection risk and HVAC energy efficiency. SIREN uses real-time building operation data and Trim & Respond control logic to determine zone primary and system outdoor airflow rates. An EnergyPlus and CONTAM co-simulation framework was developed to assess its performance across various control scenarios and US climate zones. Results show that SIREN can flexibly control infection risk within a customized threshold (e.g. 3%) for every zone, while traditional controls cannot. At the building level, SIREN's HVAC energy consumption is comparable to a fixed 70% outdoor airflow fraction scenario, while its infection risk is lower than the 100% outdoor airflow scenario, illustrating its potential for safe and energy-efficient HVAC operation during pandemics.
ABSTRACT
Recently, the importance of mechanical facilities in charge of the safety and comfort of occupants in buildings has once again been highlighted in accordance with global social issues such as the spread of COVID-19. In response, various ventilation systems are being developed to improve indoor air quality, and efforts are being made to satisfy the indoor comfort of the occupants. Such advanced facilities allow occupants to secure indoor air quality, while frequent ventilation systems can affect the cooling and heating load in the building, and there is also a problem that it can occupy a relatively large amount of space in the building. This study proposes an integrated, outdoor fan-ventilated cooling device and analyzes its performance and economic efficiency. The EnergyPlus simulation program was used to model two types of systems for comparison: an existing (base) model with a condenser located in the outdoor unit, and a developed model with the condenser integrated within the cooling system. The state of the air passing through the condenser was analyzed prior to comparing the efficiency of the integrated, outdoor fan-ventilated cooling device, followed by an in-depth analysis of the performance and economic efficiency based on total energy consumption. In Case 1, the air passing through the cooling system was approximately 5 °C lower than the base model and showed 11% peak load reduction in comparison to the maximum energy consumption. Additionally, a comparison between regions with different outdoor air temperatures showed an average cost reduction of 16% in Daejeon and Busan City.
ABSTRACT
The COVID-19 pandemic has urged the need to reconsider how our built environments influence our health conditions. The new guidelines have highlighted the importance of environmental settings in the virus transmission process. Given that external air ventilation is a major element of a building's energy performance, it is necessary to investigate the influence of the new settings on the building's energy consumption. This study aims to determine the energy performance and infection risk of underfloor air distribution UFAD and overhead systems OH when exposed to varying levels of external air ventilation. The findings indicate that raising the rate of outside ventilation increases a building's energy usage in all climates. It is also shown that the UFAD system shows its energy-saving potential the most in cold climates and higher ventilation rates. These findings suggest that it is critical to consider distinct ventilation techniques to prevent rising energy consumption rates while lowering the risk of viral transmission. © 2022 Society for Modeling & Simulation International (SCS)
ABSTRACT
Understanding the role of architectural design in identifying the risk of disease transmission is essential for creating resilience in buildings. Here we used a Grasshopper simulation workflow to execute aerosol disease transmission risk estimation coupled with EnergyPlus simulation inputs to assess the impact of architectural factors on the risk of COVID-19 transmission. We simulated the risk for a simple geometry with different window configurations and geographic locations. We observed that increasing the fractional opening of a single window as well as cross ventilation design can increase the outdoor air exchange, which corresponds to substantially reduced risk of disease transmission. Furthermore, indoor relative humidity in cold climates can be significantly lower in winter due to the impacts of increased mechanical heating which translates to an increased risk of infection. We demonstrate that early architectural design decisions implicate the resultant risk of disease transmission indoors that should be prioritized in the future. © 2022 Society for Modeling & Simulation International (SCS)
ABSTRACT
Understanding the role of architectural design in identifying the risk of disease transmission is essential for creating resilience in buildings. Here we used a Grasshopper simulation workflow to execute aerosol disease transmission risk estimation coupled with EnergyPlus simulation inputs to assess the impact of architectural factors on the risk of COVID-19 transmission. We simulated the risk for a simple geometry with different window configurations and geographic locations. We observed that increasing the fractional opening of a single window as well as cross ventilation design can increase the outdoor air exchange, which corresponds to substantially reduced risk of disease transmission. Furthermore, indoor relative humidity in cold climates can be significantly lower in winter due to the impacts of increased mechanical heating which translates to an increased risk of infection. We demonstrate that early architectural design decisions implicate the resultant risk of disease transmission indoors that should be prioritized in the future. © 2022 SCS.
ABSTRACT
The COVID-19 pandemic has urged the need to reconsider how our built environments influence our health conditions. The new guidelines have highlighted the importance of environmental settings in the virus transmission process. Given that external air ventilation is a major element of a building's energy performance, it is necessary to investigate the influence of the new settings on the building's energy consumption. This study aims to determine the energy performance and infection risk of underfloor air distribution UFAD and overhead systems OH when exposed to varying levels of external air ventilation. The findings indicate that raising the rate of outside ventilation increases a building's energy usage in all climates. It is also shown that the UFAD system shows its energy-saving potential the most in cold climates and higher ventilation rates. These findings suggest that it is critical to consider distinct ventilation techniques to prevent rising energy consumption rates while lowering the risk of viral transmission. © 2022 SCS.
ABSTRACT
Humanity is currently confronted with a new, unknown, highly contagious virus, where social isolation and increased personal hygiene seem to be the main means in preventing its spread. The world economy is very threatened by the new situation, which has not bypassed the energy sector either. The mortality rate is relatively high, people are not leaving their homes, which is directly reflected in the increase of the energy consumption in the residential sector. The same is valid for water consumption. For a household located in Kragujevac (Central Serbia), 4 simulation scenarios were analyzed (S1 - reference case, S2 - mild protection measures, S3 - semi-quarantine measures, S4 - complete quarantine) to assess the link between people's behavior (on the one hand) and the consumption of natural gas, electricity and water (on the other hand), in the residential sector, in unforeseen circumstances, such as the COVID-19 virus pandemic. The analysis was conducted numerically for the month of March 2020, using EnergyPlus software packages. In defining the above scenarios, a one-minute time step schedule of people's behavior was used, taking into account the number of family members in the household, their age, occupation, lifestyle, habits (all in accordance with cultural and socio-economic circumstances), as well as the measures taken by the Government of the Republic of Serbia to fight the pandemic. Also, an analysis of energy consumption at the level of the city of Kragujevac for the past three years was made, based on data obtained from public companies - distributors (thermal energy, natural gas, electricity, water). In this paper, an analysis of air quality for the same time period was conducted, which is closely related to energy consumption and limited population movement. The simulatinos show that the consumption of natural gas can increase by 21.26% (S2), electricity by 58.39% (S4), and the consumption of water from the city water supply network by 25.45% (S3) compared to the reference case (S1). On the other hand, based on the invoice for payment of services to distributors, the actual energy consumption that was made on the analyzed house during the month of March 2020 was: natural gas (260.36 Sm3), electricity (1418 kWh), and water (22.5 m3). The conducted economic analysis showed that the largest funds at the level of the entire facility were allocated in S3 (27.33% more than in S1), and that the actual costs were 15.09% higher than in S1, and 16.41% lower than in S2.