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 relationship between indoor environment, outdoor environment, and behavior on indoor air quality and health

2021 ◽  
Author(s):  
SDAG Lab
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
The United States ◽  
Outdoor Environment ◽  
Equation Modeling ◽  
Health Symptoms ◽  
Surface Dust ◽  
Air Purifier ◽  
The Impact

We should be concerned about the impact of indoor air quality on health because in the United States, people spend most of their time indoors. While earlier studies have characterized the odds of developing illness based on the home environment, they have not investigated the behaviors that can ameliorate the negative effect of indoor, outdoor, and behavioral sources. The purpose of this study was to 1) investigate the contributions of indoor, outdoor, and behavioral sources of pollutants on health symptoms, and 2) to identify the behaviors that can worsen or mitigate the number of health symptoms. Data came from two surveys (n=83,284) and include questions on home conditions, outdoor conditions, occupants’ behaviors, and health symptoms. I used negative binomial regression and identified that demographics and outdoor characteristics explain 2% of the variability in health symptoms, and maintenance behaviors explain 8% of the variability in health symptoms. Next, structural equation modeling (SEM) was used to examine the behaviors that can mitigate or worsen the number of health symptoms. The results show that maintenance issue such as mold result in significantly more health symptoms (β = .12, p <.001). and factors such as leaks, and frequent long shower may result in an increase in mold. Leaks may cause water stains (β = .39, p <.001) which could lead to molds (β = .47, p <.001). While frequent long shower can result in an increase in mold (β = .05, p <.001), the use of a bathroom exhaust during shower may help to reduce molds (β = -.04, p <.001). In terms of personal behaviors, the presence of carpet (β = .08, p <.001), and smoking also result in an increase in surface dust (β = .17`, p <.001) but frequent vacuuming could mitigate the impact of surface dust on health symptoms (β = -.12, p <.001). Home occupants who live near environmental hazards are also likely to use air purifier (β = .03, p <.001); however, air purifier is associated with more health symptoms (β = .05, p <.001). Based on the findings, it is recommended that home occupants engage in periodic maintenance to prevent issues such as leaks from escalating to molds, regular vacuuming to reduce the accumulation of surface dust. Regarding air purifier, it could be that participants who experienced more health symptoms were more likely to use an air purifier. However, some air purifiers are sources of ozone, therefore home occupants should err on the side of caution when it comes to air purifier (Britigan et al., 2006; Cestonaro et al., 2017).

scholarly journals Analysis of the Impact of Self-Isolation of Residents during a Pandemic on Energy Demand and Indoor Air Quality in a Single-Family Building

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6470
Author(s):  
Walery Jezierski ◽  
Mirosław Zukowski ◽  
Beata Sadowska
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Energy Demand ◽  
The Self ◽  
Single Family ◽  
Final Energy ◽  
Final Energy Demand ◽  
The Impact ◽  
Isolation Period

This work presents the results of analysis of the final energy demand (Qk) for a single-family house in a pandemic situation and accompanying self-isolation of residents. It was assumed that the object of study is located in Bialystok (Poland). This analysis covers the impact of various factors such as specific periods of the active pandemic phase, the length of the inhabitants’ self-isolation period, the number of residents at home, and the type of energy source used in the building. Based on the results of computational experiments, a deterministic mathematical model of the relationship between these variables was developed, and the effects of the selected factors on the final energy demand were analyzed for the typical meteorological year (TMY) weather data. It turned out that the change in the length of the self-isolation period from 0 to 31 days caused an increase of Qk by about 6.5% for the analyzed building. When the number of inhabitants changed from 1 to 4, Qk increased by 34.7%. A change from 4 to 7 people causes an additional 26.7% increase in Qk. It was found that the structure of energy demand for this building operation during the period of inhabitants’ self-isolation also changed. With the increase in the length of the self-isolation period from 0 to 31 days, the electricity demand (Eel) increases by about 40–42%, while the demand for energy related to fuel consumption (Qg) decreases by about 7–10%. The article also presents an analysis of the impact of residents’ self-isolation on indoor air quality (IAQ) and thermal comfort. The simulation results showed that the use of variable air volume ventilation allows the CO2 concentration to be kept significantly below the limit value.

scholarly journals Application of Wind as a Renewable Energy Source for Passive Cooling through Windcatchers Integrated with Wing Walls

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2536 ◽  
Author(s):  
Payam Nejat ◽  
Fatemeh Jomehzadeh ◽  
Hasanen Hussen ◽  
John Calautit ◽  
Muhd Abd Majid
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Passive Cooling ◽  
Quality Factors ◽  
Ventilation Performance ◽  
Wing Walls ◽  
The Impact ◽  
Ventilation Systems

Generally, two-third of a building’s energy is consumed by heating, ventilation and air-conditioning systems. One green alternative for conventional air conditioner systems is the implementation of passive cooling. Wing walls and windcatchers are two prominent passive cooling techniques which use wind as a renewable resource for cooling. However, in low wind speed regions and climates, the utilization of natural ventilation systems is accompanied by serious uncertainties. The performance of ventilation systems can be potentially enhanced by integrating windcatchers with wing walls. Since previous studies have not considered this integration, in the first part of this research the effect of this integration on the ventilation performance was assessed and the optimum angle was revealed. However, there is still gap of this combination; thus, in the second part, the impact of wing wall length on the indoor air quality factors was evaluated. This research implemented a Computational Fluid Dynamics (CFD) method to address the gap. The CFD simulation was successfully validated with experimental data from wind tunnel tests related to the previous part. Ten different lengths from 10 cm to 100 cm were analyzed and it was found that the increase in wing wall length leads to a gradual reduction in ventilation performance. Hence, the length does not have a considerable influence on the indoor air quality factors. However, the best performance was seen in 10 cm, that could provide 0.8 m/s for supply air velocity, 790 L/s for air flow rate, 39.5 1/h for air change rate, 107 s for mean age of air and 92% for air change effectiveness.

scholarly journals Seasonal variations and the influence of ventilation rates on IAQ: A case study of five low-energy London apartments

2021 ◽  
pp. 1420326X2110171
Author(s):  
Samuel Stamp ◽  
Esfand Burman ◽  
Clive Shrubsole ◽  
Lia Chatzidiakou ◽  
Dejan Mumovic ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Seasonal Variations ◽  
Natural Ventilation ◽  
Low Energy ◽  
Ventilation Rates ◽  
The Impact ◽  
Indoor And Outdoor

The indoor air quality (IAQ) of five low-energy London apartments has been assessed through the measurement of 16 key pollutants, using continuous and diffusive methods across heating and non-heating seasons. This case study approach aimed to assess the presence of pollutants within low-energy apartments and to better understand the role of ventilation and seasonal variations in indoor air quality. The results indicate strong seasonal variations, driven by increased natural ventilation rates over the summer monitoring period. A combined metric for indoor and outdoor pollutants ( Itot) suggests that the IAQ in the winter ( Itot = 17.7) is more than twice as bad as that seen in the summer ( Itot = 8.6). Formaldehyde concentrations were lower in the non-heating season, indicating increased ventilation rates more than offset increased off-gassing, in contrast to findings in other studies. However, increased summertime ventilation rates were observed to increase the proportion of outdoor pollutants entering the internal environment. This resulted in higher indoor concentrations of NO2 in the summer than the winter, despite significant reductions in outdoor concentrations. These results demonstrate the impact of ventilation practices upon IAQ, the influence of occupant actions and the complex relationship ventilation rates play in balancing indoor and outdoor sources of air pollution.

scholarly journals Numerical analysis of the impact of natural ventilation on the Indoor Air Quality and Thermal Comfort in a classroom

2019 ◽  
Vol 111 ◽  
pp. 01023 ◽  
Author(s):  
George-Mãdãlin Chitaru ◽  
Andrei Istrate ◽  
Tiberiu Catalina
Keyword(s):  
Numerical Simulation ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Simulation Software ◽  
Educational Institutions ◽  
Research School ◽  
The Impact

Indoor air quality (IAQ) inside educational institutions is an important topic in the field of building and health research. School absenteeism and educational performance have been linked to poor air quality inside classrooms. A numerical simulation software has been used to test 5 different scenarios of natural ventilation during summer and winter. CO2 levels, air relative humidity, operative temperature and PMV were used as indoor air quality and thermal comfort indicators. Results have shown high CO2 and humidity levels when all windows are closed, and a variable improvement when different natural ventilations strategies are employed. A detailed procedure for the numerical simulation has been presented.

scholarly journals Analysis of Impact of Natural Ventilation Strategies in Ventilation Rates and Indoor Environmental Acoustics Using Sensor Measurement Data in Educational Buildings

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6122
Author(s):  
María L. de la Hoz-Torres ◽  
Antonio J. Aguilar ◽  
Diego P. Ruiz ◽  
María Dolores Martínez-Aires
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Environmental Conditions ◽  
Background Noise ◽  
Natural Ventilation ◽  
Acoustic Environment ◽  
Educational Buildings ◽  
Ventilation Strategies ◽  
Ventilation Rates

Indoor environmental conditions can significantly affect occupants’ health and comfort. These conditions are especially important in educational buildings, where students, teachers and staff spend long periods of the day and are vulnerable to these factors. Recently, indoor air quality has been a focus of attention to ensure that disease transmission in these spaces is minimised. In order to increase the knowledge in this field, experimental tests have been carried out to characterise the impact of natural ventilation strategies on indoor air quality and the acoustic environment. This study has evaluated three ventilation scenarios in four different classrooms in buildings of the University of Granada, considering different window and door opening configurations. Ventilation rates were estimated using the CO2 Decay Method, and background noise recordings were made in each classroom for acoustic tests. Results show that specific natural ventilation strategies have a relevant impact that is worth considering on the background noise in indoor spaces. In this sense ventilation rates provided by the different configurations varied between 3.7 and 39.8 air changes per hour (ACH) and the acoustic tests show a background noise ranging from 43 to 54 dBA in these scenarios. Consequently, managers and teachers should take into account not only the ACH, but also other collateral impacts on the indoor environmental conditions such as the thermal comfort or the acoustic environment.

scholarly journals Keeping Cool in the Desert: Using Wind Catchers for Improved Thermal Comfort and Indoor Air Quality at Half the Energy

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 100
Author(s):  
Jamal Saif ◽  
Andrew Wright ◽  
Sanober Khattak ◽  
Kasem Elfadli
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Energy Demand ◽  
Air Conditioning ◽  
Natural Ventilation ◽  
Energy Use ◽  
Cooling System ◽  
Evaporative Cooling

In hot arid climates, air conditioning in the summer dominates energy use in buildings. In Kuwait, energy demand in buildings is dominated by cooling, which also determines the national peak electricity demand. Schools contribute significantly to cooling demand, but also suffer from poor ventilation. This paper presents analysis of a ventilation and cooling system for school classrooms using a wind catcher for natural ventilation and evaporative cooling. A school classroom in Kuwait with single-sided ventilation was modelled using the DesignBuilder V5.4/EnergyPlus V9.1 software and calibrated using field data. The model was used to analyse the performance of a wind catcher, with and without evaporative cooling, in terms of energy use, thermal comfort and indoor air quality. Compared to the baseline of using air-conditioning only, a wind catcher with evaporative cooling was found to reduce energy use by 52% during the summer months while increasing the comfortable hours from 76% to 100% without any supplementary air conditioning. While the time below the ASHRAE CO2 limit also improved from 11% to 24% with the wind catcher, the indoor air quality was still poor. These improvements came at the cost of a 14% increase in relative humidity. As the wind catcher solution appears to have potential with further development; several avenues for further research are proposed.

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