Analysis of Indoor Air Pollutants and Guidelines for Space and Physical Activities in Multi-Purpose Activity Space of Elementary Schools

Owing to the recent increase in the number of warning reports and alerts on the dangers of fine dusts, there has been an increasing concern over fine dusts among citizens. In spaces with poor ventilation, the occupants are forced to open the window to initiate natural ventilation via the direct introduction of the outside air; however, this may pose a serious challenge if the external fine-dust concentration is high. The lack of natural ventilation increases the indoor carbon dioxide (CO2) concentration, thus necessitating the installation of mechanical ventilation systems. This study analyzed the frequency of the application of mechanical ventilation systems in the Multi-purpose activity space of elementary schools, which are spaces where children require a higher indoor air quality than adults owing to the rapid increase in the CO2 concentration of the Multi-purpose activity space during activities. In addition, the architectural and equipment factors of the Multi-purpose activity spaces of nine elementary schools were characterized. The results revealed that five out of the nine elementary schools installed mechanical ventilation systems, whereas the remaining four schools installed jet air turnover systems. The indoor air quality of the Multi-purpose activity space of D elementary school, which had the minimum facility volume among the schools investigated in this study (564.2 m3), with up to 32 participants for each activity, was investigated. The results revealed that the ultrafine-dust (PM2.5) concentration of the facility was as high as 4.75 µg/m3 at a height of 1.2 m, and the CO2 concentration was as high as 3183 ppm. The results of the analysis of three elementary schools with different volumes were compared and analyzed using CONTAM simulation. This study determined the required volume per occupant and the optimum number of occupants for a given volume and presented guidelines for the optimum number of occupants, activities, and volume to reduce the high concentration of pollutants in the analyzed Multi-purpose activity space. The guideline proposed in this study is aimed at maintaining the CO2 concentration of the Multi-purpose activity space below 1000 ppm, as prescribed by the Indoor Air Quality Control in Public-Use Facilities, Etc. Act in South Korea.

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FACTORS AFFECTING VENTILATION, INDOOR-AIR QUALITY AND ACOUSTICAL QUALITY IN ‘GREEN’ AND NON-‘GREEN’ BUILDINGS: A PILOT STUDY

Journal of Green Building ◽

10.3992/jgb.6.3.168 ◽

2011 ◽

Vol 6 (3) ◽

pp. 168-180 ◽

Cited By ~ 3

Author(s):

Alireza Khaleghi ◽

Karen Bartlett ◽

Murray Hodgson

Keyword(s):

Mechanical Ventilation ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Natural Ventilation ◽

Sound Pressure ◽

Low Frequency ◽

Green Buildings ◽

Noise Levels ◽

Ventilation Rates

This paper discusses a pilot project involving the direct monitoring of ventilation, indoor-air quality and the acoustical conditions in selected nominally ‘green’ and non-‘green’ buildings located on a university campus. The objectives were to measure parameters quantifying these three aspects of indoor environmental quality, determine the relationships between them and the building-design concepts, and evaluate the implications of the results for ventilation-system design, especially in ‘green’ buildings. Measurements were made in rooms, with and without acoustical treatment, in buildings with natural ventilation or mechanical (displacement and/or mixed-flow) ventilation systems. Measurements were made of ventilation rates (air changes per hour), indoor air quality (respirable-fibre, total-VOC and ultrafine-particulate concentrations), and the acoustical conditions (noise levels and reverberation times). Correlations between the environmental results, the building concept, the ventilation concept and the building window status were explored. In rooms with natural ventilation, low-frequency noise and total sound-pressure levels were lower; however, the rooms had higher ultrafine-particulate counts and lower ventilation rates. Rooms with mechanical ventilation had higher low-frequency and total sound-pressure levels, higher ventilation rates and fibre concentrations, but lower concentrations of ultrafine particulates. It was concluded that, in general, mechanical ventilation can provide better indoor air-quality, but that HVAC noise is an issue if the system is not properly designed. In ‘green’ buildings, noise levels were acceptable when the windows were closed, but increasing the ventilation rate by opening the windows resulted in higher noise levels. The results suggest that the acceptability of environmental factors in buildings depends on the degree of compliance of the design and its implementation with standards and design guidelines (i.e. for ventilation, air quality, thermal comfort, etc.), whether the original design concept is ‘green’ or non-‘green’.

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The Applicability of Coanda Effect Hysteresis for Designing Unsteady Ventilation Systems

Energies ◽

10.3390/en14010034 ◽

2020 ◽

Vol 14 (1) ◽

pp. 34

Author(s):

Aldona Skotnicka-Siepsiak

Keyword(s):

Mechanical Ventilation ◽

Energy Efficiency ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Residential Buildings ◽

Coanda Effect ◽

Air Jet ◽

Coandǎ Effect ◽

Ventilation Systems

Energy-saving ventilation systems are designed to improve the energy efficiency of buildings. Low energy efficiency in buildings poses a considerable problem that needs to be addressed. Mechanical ventilation with heat recovery has gained increased popularity in recent years. Mechanical ventilation has numerous advantages, including easy adjustment and control, high indoor air quality and elimination of indoor pollutants. Mixing ventilation is the most popular type of mechanical ventilation, in particular in residential buildings. Unsteady ventilation is a type of mixing ventilation that involves stronger mixing effects and smaller vertical temperature gradients to improve indoor air quality (IAQ) and minimize energy consumption. This study examines the possibility of controlling and modifying Coanda effect hysteresis (CEH) to generate unsteady flow and simulate the conditions of unsteady mixing ventilation. The experiment was performed on a self-designed test bench at the University of Warmia and Mazury in Olsztyn. It demonstrated that an auxiliary nozzle can be applied at the diffuser outlet to control CEH and the angles at which the air jet becomes attached to and separated from the flat plate positioned directly behind the nozzle. The study proposes an innovative mixing ventilation system that relies on CEH. The potential of the discussed concept has not been recognized or deployed in practice to date. This is the first study to confirm that an auxiliary nozzle by the diffuser outlet can be operated in both injection and suction mode to control CEH. In the future, the results can be used to design a new type of nozzles for unsteady ventilation systems that are based on CEH control.

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Numerical Assessment of Seven Ventilation Systems for Social Residential Buildings based on Indoor Air Quality and Energy Consumption

Journal of Physics Conference Series ◽

10.1088/1742-6596/2069/1/012181 ◽

2021 ◽

Vol 2069 (1) ◽

pp. 012181

Author(s):

Guillaume Sérafin ◽

Marc O. Abadie ◽

Patrice Joubert

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Natural Ventilation ◽

Residential Buildings ◽

Living Room ◽

Internal Sources ◽

Controlled Mechanical Systems ◽

Ventilation Systems

Abstract This work presents a modelling approach for evaluating ventilation systems for their ability to provide good indoor air quality in dwellings. Infiltration and ventilation rates are defined by the conventional French 3CL-DPE standard. The case study is a two-bedroom apartment with a shared or separate kitchen and living room. Three natural ventilation options and four mechanical ventilation systems are compared with respect to exposure to PM2.5, NO2 and formaldehyde. Pollutant concentration levels are assessed in each room based on a scenario of daily occupancy, average annual outdoor concentrations and internal sources. The daily exposure of the occupants to the targeted substances allows the comparison of ventilation systems on the basis of the ULR-QAI index developed at LaSIE laboratory from La Rochelle University. For this case study, it results that controlled mechanical systems are much more efficient than natural ventilation systems, especially in the case of an open-plan kitchen.

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Identifying mechanical ventilation issues in classrooms

E3S Web of Conferences ◽

10.1051/e3sconf/20184400055 ◽

2018 ◽

Vol 44 ◽

pp. 00055

Author(s):

Julia Janiga ◽

Joanna Krzempka ◽

Aleksandra Szczerbińska

Keyword(s):

Mechanical Ventilation ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Ventilation System ◽

Operating Time ◽

Mechanically Ventilated ◽

Ventilation Systems

This article focuses on the issues of indoor air quality in mechanically ventilated classrooms. The aim of the study was to determine the reasons for inadequate air quality reported by occupants. Two different ventilation systems were assessed by measuring CO2 and VOC concentrations in classrooms during operating time. Results showed that in both cases, CO2 levels in the air, even though mostly acceptable, were exceeded throughout the measuring periods on occasion. Based on obtained data, in both cases probable causes for reported ventilation system malfunctions were proposed.

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A Field Survey on Indoor Air Pollution in School Classrooms with Different Ventilation Methods

E3S Web of Conferences ◽

10.1051/e3sconf/201911101020 ◽

2019 ◽

Vol 111 ◽

pp. 01020

Author(s):

Ko Murakami ◽

Kenta Sakai ◽

Daisuke Nakamura ◽

Haruno Ishikawa ◽

Sayana Tsushima ◽

...

Keyword(s):

Elementary Schools ◽

Heat Exchange ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Indoor Air Pollution ◽

Ventilation System ◽

Co2 Concentration ◽

Field Surveys ◽

Air Conditioning Systems

The purpose of this study was to investigate the actual indoor air quality within two elementary schools with different types of ventilation methods, and to obtain data pertaining to the emission of bioeffluents within the schools. Field surveys on indoor air quality were conducted at two public elementary schools in Tokyo, both equipped with air-conditioning systems. School-A was also equipped with a heat-exchange ventilation system, while School-B did not have a ventilation system. Results of the study revealed that the target ventilation volume for the heat-exchange ventilation system in School-A was not achieved, indoor air quality in School-B was better in relatively cool conditions than School-A because of the habit of opening windows attached, there was a positive correlation between nonanal and decanal and CO2 concentration in summer, and the concentration of bioeffluents nonanal and decanal may be higher at high temperatures even under the same level of ventilation.

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

Energies ◽

10.3390/en11102536 ◽

2018 ◽

Vol 11 (10) ◽

pp. 2536 ◽

Cited By ~ 13

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.

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Indoor air quality and control methods for mechanical ventilation systems inside large passive objects

Czasopismo Techniczne ◽

10.37705/techtrans/e2020001 ◽

2020 ◽

pp. 1-8

Author(s):

Nina Szczepanik-Ścisło

Keyword(s):

Mechanical Ventilation ◽

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Test Object ◽

Control Methods ◽

And Control ◽

Sanitary Conditions ◽

Ventilation Systems

This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants. This paper summarises the indoor air quality of a sports hall built in the passive standard. The sanitary conditions within the object were measured and analysed to identify whether the standards were met and if the test object was safe for occupants.

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Indoor Air Quality and Sustainability Management—Case Study in Three Portuguese Healthcare Units

Sustainability ◽

10.3390/su11010101 ◽

2018 ◽

Vol 11 (1) ◽

pp. 101 ◽

Cited By ~ 7

Author(s):

Ana Fonseca ◽

Isabel Abreu ◽

Maria Guerreiro ◽

Cristina Abreu ◽

Ricardo Silva ◽

...

Keyword(s):

Air Quality ◽

Relative Humidity ◽

Indoor Air Quality ◽

Indoor Air ◽

Natural Ventilation ◽

Health And Safety ◽

Co2 Concentration ◽

Healthcare Facilities ◽

June July ◽

Management Case Study

Adequate management of indoor air quality (IAQ) in healthcare units has relevant impacts on sustainability performance due to its effects on patient safety, occupational health and safety, and energy consumptions. This study sought to identify improvement opportunities on IAQ management by collecting and analyzing experimental data of selected parameters in three healthcare units in Portugal: Two general hospitals and one primary healthcare center. Indoor air temperature, relative humidity, CO2, bacteria, and fungi concentrations were measured in summer and winter campaigns in June/July 2017 and in January/March 2018. Results show that the exclusive use of natural ventilation is not adequate when the affluence of users is high, but the analyzed parameters revealed acceptable results under low occupation intensity conditions. Results also show that keeping low indoor air relative humidity has a significant impact in reducing fungi concentration and that there is a significant correlation at the 0.05 level between indoor air CO2 concentration and bacterial loads. Therefore, as opportunities to improve sustainability, IAQ management in healthcare facilities should consider natural ventilation as a complement to mechanical ventilation systems and should focus on adequate control of indoor air relative humidity and CO2 concentration to reduce the risk of airborne infections.

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Computational Analysis of a Lecture Room Ventilation System

Zero-Energy Buildings - New Approaches and Technologies ◽

10.5772/intechopen.92725 ◽

2020 ◽

Author(s):

Abayomi Layeni ◽

Collins Nwaokocha ◽

Olalekan Olamide ◽

Solomon Giwa ◽

Samuel Tongo ◽

...

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Natural Ventilation ◽

Ventilation System ◽

Minimum Cost ◽

Solar Chimney ◽

Lecture Room ◽

Room Ventilation System ◽

Ventilation Systems

The level of Indoor Air Quality (IAQ) has become a big topic of research, and improving it using passive ventilation methods is imperative due to the cost saving potentials. Designing lecture buildings to use less energy or Zero Energy (ZE) has become more important, and analysing buildings before construction can save money in design changes. This research analyses the performance (thermal comfort [TC]) of a lecture room, investigate the use of passive ventilation methods and determine the energy-saving potential of the proposed passive ventilation method using Computational Fluid Dynamics (CFD). Results obtained showed that air change per hour at a wind velocity of 0.05 m/s was 3.10, which was below standards. Therefore, the lecture hall needs external passive ventilation systems (Solar Chimney [SC]) for improved indoor air quality at minimum cost. Also, it was observed that the proposed passive ventilation (SC) system with the size between 1 and 100 m3, made an improvement upon the natural ventilation in the room. There was a 66.69% increase after 10 years in the saving of energy and cost using Solar Chimney as compared to Fans, which depicts that truly energy and cost were saved using passive ventilation systems rather than mechanical ventilation systems.

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Indoor air quality in a preschool

Budownictwo i Architektura ◽

10.35784/bud-arch.1691 ◽

2014 ◽

Vol 13 (4) ◽

pp. 041-048

Author(s):

Marek Telejko

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Natural Ventilation ◽

Ventilation System ◽

Carbon Dioxide Concentration ◽

Co2 Concentration ◽

Maximum Efficiency ◽

Outdoor Air ◽

Legal Requirements

The article presents the results of indoor air quality (IAQ) assessment in four local preschools. The natural ventilation system was used in the buildings. Outdoor air was supplied to the premises through a leak in the external walls and air intakes were of maximum efficiency of 30 m3/h. Parameters describing IAQ were measured, such as: temperature, relative humidity and carbon dioxide concentration. Two series of studies were performed in each preschool. On the basis of the survey, it can be clearly stated that the indoor air quality in preschools is considered to be very low very low. All the analyzed parameters describing the quality do not meet the current legal requirements. Reported values of CO2 concentration exceeded three times the value set of the recommended maximum.

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