scholarly journals Improving Indoor Air Quality in Classrooms via Wind-Induced Natural Ventilation

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Mohannad Bayoumi
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
User Satisfaction ◽  
Natural Ventilation ◽  
Special Treatment ◽  
Generic Model ◽  
Change Rate ◽  
Air Change Rate ◽  
Warm Climates

Student performance in classrooms is related to the indoor environmental quality. High air change rates are necessary to secure an acceptable level of indoor air quality and provide fresh air, which require large amounts of energy and technical installations. Mostly, mechanically supplied air is partially mixed with the return air. In warm climates, the capacity for natural ventilation is not fully exploited in modern buildings. During periods of acceptable outdoor temperatures, buildings need to adapt and employ available free renewable resources, such as wind. In this context, the building form, orientation, and envelope openings are crucial to enable an increased air change rate, user satisfaction, and energy savings. Owing to the difficulty of providing cross-ventilation in buildings with double-loaded corridors, single-sided ventilation is the most common approach. This study investigates the methods to improve the wind-driven air exchange of classrooms in warm climates, where naturally ventilated corridors help increase air movement. This study examines the potential of a set of alternatives within the context of a generic model regarding the pressure distribution, thermal sensation, air velocity, and air change rate. The study suggests that no single opening scenario can be applied to all façades at any time. Each façade requires special treatment. Decisions on natural ventilation need to be made during the early design stages for each façade. It was found that with the aid of low-tech modifications, remarkable increases in air change rates, in some cases up to 14.5 times that of the typical single-sided ventilation case, could be achieved.

scholarly journals Quality of life control by selected methods of air exchange in a typical apartment building

2021 ◽  
Author(s):  
Iveta Bullová ◽  
Peter Kapalo ◽  
Dušan Katunský
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Allergic Diseases ◽  
Well Being ◽  
Indoor Climate ◽  
Apartment Building ◽  
Change Rate ◽  
Air Change Rate ◽  
Negative Effect

Air change rate is an important parameter for quantification of ventilation heat losses and also affects the indoor climate of buildings. Indoor air quality is significantly associated with ventilation. If air change isn't sufficient, trapped allergens, pollutants and irritants can degrade the indoor air quality and affect the well-being of a building's occupants. Many studies on ventilation and health have concluded that lower air change rates can have a negative effect on people’s health and low ventilation may result in an increase in allergic diseases. Quantification of air change rate is complicated, since it is affected by a number of parameters, of which the one of the most variable is the air-wind flow. This study aims to determination and comparison of values of the air change rate in two methods - by quantifying of aerodynamic coefficient Cp = Cpe - Cpi – so called aerodynamic quantification of the building and the methodology based on experimental measurements of carbon dioxide in the selected reference room in apartment building.

Numerical Study on Indoor Air Quality of Commercial Kitchen in China

2011 ◽  
Vol 374-377 ◽  
pp. 1100-1105 ◽  
Author(s):  
Xiao Tan Hou ◽  
An Gui Li ◽  
Zhi Hua Wang ◽  
Yu Jiao Zhao
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Numerical Study ◽  
Average Concentration ◽  
Energy Utilization ◽  
Change Rate ◽  
Air Supply ◽  
Air Change Rate

Indoor air quality of commercial kitchen is investigated and analyzed through velocity, temperature, humidity, and CO2 concentration under different air change rate and supply air temperature. the best air change rate is 30 times per hour and air supply temperature is 301.15K for kitchen, the mean value of the minimum velocity and standard deviation is 0.410m/s and 0.129 respectively, the maximum of the average concentration of CO2 is 659.78ppm, which is less than the acceptance criteria (CO2<1000ppm), and the energy utilization coefficient is maximum of 1.352. Research results show that this air supply mode can optimize indoor air quality.

scholarly journals ANALYSIS OF THE INFLUENCE OF AIR EXCHANGE DISTRIBUTION BETWEEN ROOMS ON THE APARTMENT ENERGY CONSUMPTION

2021 ◽  
pp. 39-50
Author(s):  
V. Deshko ◽  
I. Bilous ◽  
I. Sukhodub ◽  
O. Yatsenko
Keyword(s):  
Energy Consumption ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Building Energy ◽  
Optimal Operation ◽  
Change Rate ◽  
Air Change Rate ◽  
Building Engineering ◽  
Air Exchange

Modern results of Ukrainian buildings energy analysis show that 30-50% of the energy for heating goes to heat the supply air, and that is the largest share in the building energy balance. In terms of energy consumption, efficiency of the air exchange mode largely depends on occupancy schedule and air distribution in time and space. The application of air exchange schedule approach makes more sense in case when individual heating control is carried out. Therefore, during occupied hours, the comfortable ventilation level can be ensured, and, during unoccupied hours, it can be reduced to a minimum. According to the results of the study, the use of intermittent air exchange mode in the studied apartment on weekdays, leads to decrease in energy consumption compared to constant air exchange at the level of upper values of the ventilation schedule. In terms of energy efficiency, the use of the constant air change rate from ASHRAE Std 62 is the most efficient approach. In terms of indoor air quality and concentration of CO2 and VOCs, the scheduled air exchange approach with increased air change rates (from EN 16798) during occupied hours is more efficient. Therefore, the use of required and experimental air change rate values to create the hourly schedules allows to define more precisely a building energy consumption and to choose an optimal operation schedule for building engineering systems to provide thermal comfort and indoor air quality during occupied hours.

scholarly journals Influence of the Airflow in a Solar Passive Building on the Indoor Air Quality and Thermal Comfort Levels

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 766 ◽  
Author(s):  
Eusébio Conceição ◽  
João Gomes ◽  
Hazim Awbi
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Numerical Study ◽  
Change Rate ◽  
Comfort Levels ◽  
Air Change Rate ◽  
Typical Summer ◽  
Shading Devices

The influence of the airflow in a solar passive building on the indoor air quality and thermal comfort levels was investigated. The numerical study for a university library was conducted using a software that simulates the building thermal behavior with complex topology, in transient conditions, for evaluating the indoor air quality and occupants’ thermal comfort levels for typical summer and winter days. Solar radiation was used as a renewable energy source to increase simultaneously the thermal comfort and air quality levels and reduce building energy consumption. Regarding the solar passive building, consideration was given to all of the building structure envelope, shading devices and interior details, while in the solar active building active ventilation was used. To analyze the airflow that simultaneously provides the best indoor air quality and thermal comfort levels, a new integral methodology based on the minimization of the total number of uncomfortable hours was used. The results show that it was possible to determine an air change rate that ensures a good compromise between thermal comfort and indoor air quality. An optimal air change rate of two and three renewals per hour had been determined, respectively, for winter and summer conditions.

scholarly journals Pengaruh Ventilasi Alami Terhadap Sick Building Syndrome

Arsitektura ◽  
2019 ◽  
Vol 17 (2) ◽  
pp. 211
Author(s):  
Fisa Savanti ◽  
Gagoek Hardiman ◽  
Erni Setyowati
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Sick Building Syndrome ◽  
Air Conditioner ◽  
Waiting Room ◽  
Air Change Rate ◽  
Sick Building ◽  
Quantitative Descriptive

<p><em>The number of buildings that use air conditioner (AC), causing a lack of air change rate from the outside into the room or vice versa that can reduce indoor air quality. A bad indoor air quality is often give rise to complaints on its occupants called the "Sick Building Syndrome" (SBS). The presence of ventilation is expected to improve air quality and increase user comfort and wellness rooms. Therefore, the research on the influence of natural ventilation against sick building syndrome (SBS) is needed. This research was conducted with quantitative-descriptive methods with direct measurements of temperature, humidity and vloumetric air flow rate on samples of objects namely RSND clinic waiting room on the 2nd floor. As for analysis is carried out descriptively based on recommended standards. The purpose of doing this research is to know the influence of natural ventilation to the indoor air quality towards sick buiding syndrome. The result of this research show that the temperature, humidity and the clean air needs of the room doesn’t meet the standarts, meanwhile the air change per hour meet the standarts on some spots. So, there is some influence of the use of natural ventilation that can improve the indoor air quality which is relating to sick building syndrome.</em></p>

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.

scholarly journals Indoor Air Quality (IAQ): Accuracy of Natural Ventilation for Temperature, Air Flow Rate and Relative Humidity (RH) in School Building Classrooms

2018 ◽  
Vol 7 (3.9) ◽  
pp. 42
Author(s):  
Norsafiah Norazman ◽  
Adi Irfan Che Ani ◽  
Nor Haslina Ja’afar ◽  
Muhamad Azry Khoiry
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Air Flow ◽  
Weather Conditions ◽  
Potential Health ◽  
The Hours ◽  
Hot Weather

Indoor Air Quality (IAQ) is an essential matter in achieving students’ satisfaction for the learning process. Building’s orientation is a factor that may encourage sufficient natural ventilation for the classroom occupants. Inadequate ventilation is an issue for most existing classrooms. The purpose of this paper is to analyze the accuracy of natural ventilation in classrooms. Therefore, experimental on 20 classrooms has been conducted by using Multipurpose Meter at secondary school buildings in Malaysia. The findings indicated that the accuracy of natural ventilation testing was below the permissible limits throughout the hours monitored, thus this may cause potential health hazards to the students. Temperature and air flow rates were lower than 23 °C and 0.15 m/s respectively, it fulfilled the basic requirements as a standard learning environment. However, measurements taken showed the overall relative humidity (RH) in the classrooms can be categorized as acceptable with 40% to 70% range. On the basis of these findings, it is evident that naturally ventilated classrooms are important especially due to energy efficiency, whereas mechanical ventilation should only be installed as an alternative under extremely hot weather conditions.   

The Potential of Natural Ventilation in Single-Sided Ventilated Apartment to Improve Indoor Thermal Comfort and Air Quality

2011 ◽  
Author(s):  
M. F. Mohamed ◽  
M. Behnia ◽  
S. King ◽  
D. Prasad
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Architectural Element ◽  
Flat Design ◽  
Effective Ventilation ◽  
Computational Fluid Dynamics Cfd ◽  
Ventilation Performance

Cross ventilation is a more effective ventilation strategy in comparison to single-sided ventilation. In the NSW Residential Flat Design Code1 (RFDC) the majority of apartments are required to adopt cross ventilation. However, in the case of studio and one-bedroom apartments, it is acknowledged that single-sided ventilation may prevail. Deep plan studio and one-bedroom apartments may achieve lower amenity of summer thermal comfort and indoor air quality where mechanical ventilation is not provided by air conditioning. Since compliance with the code may allow up to 40% of apartments in a development in Sydney to be single sided, it is important to understand the natural ventilation performance of such apartments. The objective of this paper is to investigate the natural ventilation potential in single-sided ventilated apartments to improve indoor air quality and thermal comfort. This investigation includes simulating various facade treatments involving multiple opening and balcony configurations. Balcony configurations are included in this study because, in Sydney, a balcony is a compulsory architectural element in any apartment building. The study uses computational fluid dynamics (CFD) software to simulate and predict the ventilation performance of each apartment configuration. This study suggests that properly configured balconies and openings can significantly improve indoor ventilation performance for enhanced indoor air quality and thermal comfort, by optimizing the available prevailing wind. However, it is important to note that inappropriately designed fac¸ade treatments also could diminish natural ventilation performance.

Sign in / Sign up

Export Citation Format

Share Document