scholarly journals Effects of Climatic Conditions, Season and Environmental Factors on CO2 Concentrations in Naturally Ventilated Primary Schools in Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Building Design ◽  
Climatic Conditions ◽  
Indoor Environmental Quality ◽  
Co2 Concentrations ◽  
The Impact

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.

scholarly journals Air Enthalpy as an IAQ Indicator in Hot and Humid Environment—Experimental Evaluation

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1481 ◽  
Author(s):  
Michał Piasecki ◽  
Krystyna Kostyrko ◽  
Małgorzata Fedorczak-Cisak ◽  
Katarzyna Nowak
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Test Chamber ◽  
Indoor Environmental Quality ◽  
Zero Energy Building ◽  
Experimental Function ◽  
Experimental Values ◽  
The Impact

The authors studied the impact of indoor air humidity in the range of 60% to 90% on building user perception in the temperature range of 26 to 28 °C. The research thesis was put forward that the impact of humidity on indoor air quality dissatisfaction of building users in a warm and humid indoor environment is greater than that indicated in thermal comfort models. The presented experiment examined the indoor air quality perception of n = 28 subjects in the test chamber of a nearly zero energy building under ten environmental conditions, together with a thermal comfort assessment. The authors developed an experimental relation for predicting building users’ satisfaction based on the Weber–Fechner law, where the predicted percentage of dissatisfied users (PD) is determined by means of air enthalpy (h), PD = f(h). The obtained results confirmed the sated thesis. Additionally, the intersection points of the experimental function and isotherms resulting from the Fanger model are presented, where the thermal comfort assessment starts to indicate lower user dissatisfaction results than experimental values. The authors recommend the experimental equation for humid air enthalpies in the range of 50 to 90 kJ/kg. The indoor air quality assessment based on the enthalpy value is simple and can be used to determine the overall Indoor Environmental Quality index of a building (IEQindex).

Numerical and Experimental Analysis on Indoor Thermal Environment in Commercial Kitchen

2012 ◽  
Vol 518-523 ◽  
pp. 4435-4438
Author(s):  
Da Hua Jiang ◽  
Zhi Hua Wang ◽  
Fa En Shi ◽  
Ru Shan Ren
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Thermal Environment ◽  
Co2 Concentration ◽  
Maximum Value ◽  
Work Area ◽  
Indoor Contaminants ◽  
The Impact

It is of great importance to study the impact of the cooking generated contaminants on the indoor air quality in the kitchen since cooking is regarded as the main source of indoor contaminants. This study aims investigate and analysis the indoor air quality of kitchen with using CFD numerical analysis method via the velocity, temperature, humidity CO2 concentration .It is concluded that The temperature distribution are large difference in the kitchen and the maximum value is up to 324K on the work area which near the cooking ,and the CO2 concentration which is close to the stove is 1420ppm,1370ppm, 1470ppm respectively, and it is more than the acceptance criteria (CO2<1000ppm) 42%,37% and 47% respectively. It is serious impact on the staff's physical health.

scholarly journals Investigation and Evaluation of Winter Indoor Air Quality of Primary Schools in Severe Cold Weather Areas of China

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1602 ◽  
Author(s):  
Fusheng Ma ◽  
Changhong Zhan ◽  
Xiaoyang Xu
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Co2 Concentration ◽  
Ventilation Rate ◽  
Cold Weather ◽  
Limited Information ◽  
Physical Measurements ◽  
Window Opening

The indoor air quality (IAQ) in classrooms has attracted more and more attention. Unfortunately, there is limited information relating to IAQ in the primary schools in severe cold weather areas of China. In this study, a field investigation on the IAQ of a primary school of Shenyang in northeast China was carried out by physical measurements and questionnaire surveys. The carbon dioxide (CO2) concentration in selected classrooms was continuously measured for a week, and the corresponding ventilation rate was calculated. Meanwhile, the perceptions of the IAQ, the purpose and the comfort degree of window opening have also been recorded from 106 pupils, aged 9–12. The results indicate the ventilation rate is considerably inadequate in about 99% of the class time due to the low frequency of window opening. The average daily CO2 concentration in these classrooms is 1510–3863 ppm, which is far higher than the recommended value of 1000 ppm. Most pupils understand that the purpose of opening windows in winter is to improve air quality. However, there are big differences between the measurement results and subjective judgments of indoor air quality. Contrary to the high measured CO2 concentration, around 70% pupils consider the air fresh, and only 3.7% pupils are dissatisfied and even very dissatisfied with IAQ in their classroom. It is necessary to change the existing manual window opening mode, because the pupils’ subjective judgment affects the window opening behavior.

scholarly journals Effects of the COVID-19 Pandemic on Indoor Air Quality and Thermal Comfort of Primary Schools in Winter in a Mediterranean Climate

2021 ◽  
Vol 13 (5) ◽  
pp. 2699
Author(s):  
Alicia Alonso ◽  
Jesús Llanos ◽  
Rocío Escandón ◽  
Juan J. Sendra
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Primary Schools ◽  
Indoor Environmental Quality ◽  
Indoor Environments ◽  
Thermal Discomfort ◽  
Air Supply ◽  
Hybrid Ventilation

Research studies have shown the potential effects of indoor environmental quality (IEQ) on pupils’ health and academic performance. The COVID-19 pandemic has prompted renewed interest in the assessment of deficient indoor air quality (IAQ) conditions in schools and has become a priority over achieving adequate comfort conditions. Scientific studies confirm aerosols as one of the transmission routes of SARS-CoV-2 so that the possibility of airborne transmission increases in indoor environments with high occupancy, such as classrooms. As a result, international protocols and guidelines have established a requirement for educational buildings to over-ventilate with a fresh outdoor air supply. The main object of this work is to analyse the effects of the COVID-19 pandemic on thermal comfort and indoor air quality, in winter, in two classrooms of southern Spain. Thus, onsite measurements of environmental variables were conducted before and during the pandemic. Both classrooms have mechanical ventilation systems as they are within a recently built primary school (2018). Results shows a decrease of 300 ppm in CO2 weekly average values during the pandemic, when hybrid ventilation is used, and a decrease of 400 ppm when schools are naturally ventilated during all teaching hours. However, the analysis of standards shows that over 60% of hours are thermal discomfort conditions.

scholarly journals Building performance evaluation: Balancing energy and indoor environmental quality in a UK school building

2019 ◽  
Vol 41 (3) ◽  
pp. 343-360 ◽  
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Craig Robertson ◽  
Samuel Stamp ◽  
Clive Shrubsole ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Environmental Quality ◽  
Indoor Air ◽  
Building Design ◽  
Building Performance ◽  
Indoor Environmental Quality ◽  
Low Carbon ◽  
Performance Gap

There is a policy-driven focus, at present, on improving the energy performance of buildings. However, energy-related issues alone do not capture the full impact of buildings on occupants and the wider environment. The performance of a building also includes occupant wellbeing and indoor environmental quality. Specifically, in schools, indoor environmental quality (thermal comfort, indoor air quality, lighting and acoustics) is an important aspect. Additionally, the issue of the ‘performance gap’, generally focused on energy, also affects indoor environmental quality parameters and needs to be addressed holistically. This paper reports on a holistic building performance evaluation covering aspects of energy, thermal comfort, indoor air quality, lighting and acoustics. It assesses the performance issues and inter-relationships between energy and indoor environmental quality in a recently built school campus in London. Based on the evidence collated from this case study and supplementary literature, the endemic issues and constraints within the construction industry are explored, such as inappropriate design calculations and resistance to new low-carbon technologies. Further, lessons for improved performance in the design, operation and maintenance of schools are highlighted such as factoring in the changing building use trends during design and the significance of optimal operations and maintenance of building systems for better energy and indoor environmental quality performance. This study shows that if the building design focus primarily remains on energy, unintended consequence of indoor environmental quality underperformance may occur where there are conflicts between energy and indoor environmental quality objectives. An integrated approach to building performance can help address this issue. Practical application: There are often conflicts between energy efficiency and indoor environmental quality (IEQ) objectives in building design and operation. Most building performance evaluations are primarily focused on one set of these performance criteria. This building performance evaluation was done with an integrated energy and IEQ perspective. The study identifies the causes of underperformance in energy and IEQ in a recently built school in London. Some of the findings from this study provide lessons that are relevant across the industry for the delivery of low-carbon and healthy buildings. These lessons include methods to further strengthen the policy frameworks and design protocols along with overall improvements in the processes followed during design, construction and operation of schools and other non-domestic buildings. The paper can also inform building designers, contractors and facility managers about the ways to reduce the performance gap and achieve energy targets without unintended consequences for indoor environment.

scholarly journals The Way of Usage and Location in a Big City Agglomeration as Impact Factors of the Nurseries Indoor Air Quality

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7534
Author(s):  
Małgorzata Basińska ◽  
Katarzyna Ratajczak ◽  
Michał Michałkiewicz ◽  
Paweł Fuć ◽  
Maciej Siedlecki
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Co2 Concentration ◽  
Pollutant Emissions ◽  
Impact Factors ◽  
Outdoor Air ◽  
Pm2.5 And Pm10 ◽  
The Impact

The quality of outdoor air in many places, especially in urbanized areas, is bad; therefore, a series of studies aimed at assessing the impact of outdoor air parameters on indoor air quality was conducted. Four nurseries (three buildings) located in different parts of Poznań, Poland were selected as research sites. During the research period, the concentrations of CO2, PM2.5, and PM10 inside and outside the buildings over time were analyzed. Measurements outside the buildings were supplemented with an analysis of traffic near nurseries and an assessment of pollutant emissions from vehicles of various categories. Measurements were conducted during the COVID-19 pandemic in a weekly series during winter (December)—(W), spring (April)—(S), and at the end of spring (June)—(LS). Testing and analyses indicated poor indoor air quality in three out of four nurseries. To ensure indoor air quality at the proper level, it is necessary to supply rooms with outside air. Ventilating rooms by airing, when the outside air is polluted, reduces the CO2 concentration but worsens the indoor air quality in terms of particulate matter (PM). Seasonality in the concentration of particulate matter in outdoor air and its connection with the outside air temperature was noticed. No relationship between traffic and the values of PM10 and CO2 concentrations inside nurseries was observed.

scholarly journals Occupants’ Interaction With an Occupant Voting System for Thermal and Indoor Air Quality Feedback – Case Studies in Office Spaces

2021 ◽  
Vol 7 ◽  
Author(s):  
Donya Sheikh Khan ◽  
Jakub Kolarik ◽  
Peter Weitzmann
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Case Studies ◽  
Indoor Air ◽  
Thermal Environment ◽  
Office Buildings ◽  
Indoor Environmental Quality ◽  
Quality Feedback ◽  
The Impact

Occupants can provide valuable feedback on the indoor environmental quality of buildings. Research on occupant voting systems (OVS) has demonstrated that apps or electronic devices can act as viable tools for collecting long-term feedback from occupants. However, previous research has only to a limited extent explored occupants’ interaction with OVS and the impact it might have on the reliability of the collected feedback. The present paper presents three case studies on applying a tangible OVS, denoted TiAQ, to collect feedback on thermal and indoor air quality (IAQ) in office spaces. The main objective of the present study was first to explore occupants’ interaction with TiAQ and their motivation. Second, identifying whether feedback collected with TiAQ could represent occupants’ comfort and discomfort with the thermal environment and IAQ. Thirdly, identifying challenges related to occupants’ interaction with TiAQ that might affect the representativeness of collected feedback. The present study was conducted at three office buildings in up to 7 months and demonstrated that TiAQ was suitable for collecting long-term feedback on occupants’ comfort and discomfort with the thermal environment. On average, one vote was cast per day per occupant. Additionally, in one of the office buildings, 60% of occupants reported to have interacted with TiAQ daily or weekly when, e.g., passing the device going to/from the office spaces. Occupants’ expectations of TiAQ and getting “feedback on feedback” need to be further addressed to identify ways to sustain occupants’ long-term use of the device and reduce “ill-willed” interactions.

scholarly journals Interior surface materials as sources of indoor hygiene defects

2018 ◽  
Vol 146 ◽  
pp. 03001
Author(s):  
Ingrid Juhasova Senitkova
Keyword(s):  
Air Quality ◽  
Volatile Organic Compounds ◽  
Indoor Air Quality ◽  
Organic Compounds ◽  
Indoor Air ◽  
Building Design ◽  
Interior Surface ◽  
Volatile Organic ◽  
Surface Materials ◽  
The Impact

The building design and material selection has to respect the environmental requirements of indoor air quality and indoor hygiene parameters. As the first stage of building design is the most important for final indoor air quality more and more by clear constructional architecture the benefit of environmental safety, good indoor air quality for health and productivity are dominant. Nowadays the interior surface materials have received greatest attention as sources of indoor air pollution. The major pollutants in indoor air are volatile organic compounds emitted from materials and building products. Volatile organic compounds, or VOCs, are among the most complex and troubling indoor air pollutants. Manufactured and synthesized products often release large quantities of VOCs, some of the compounds they release, such as benzene, styrene, formaldehyde, and toluene, may be irritating, toxic, or even carcinogenic. VOCs emitted can become attached to other surfaces in the space, especially fabrics, and then be re-emitted over time. The impact of interior surface materials on air quality and indoor hygiene is discussed within the paper. The building design concerning to heath of occupants and hygienic performance regime can be realized only by interdisciplinary team of professionals respecting the environmental building and indoor design.

scholarly journals Building Performance Evaluation of a New Hospital Building in the UK: Balancing Indoor Environmental Quality and Energy Performance

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 115
Author(s):  
Nishesh Jain ◽  
Esfand Burman ◽  
Samuel Stamp ◽  
Clive Shrubsole ◽  
Roderic Bunn ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Environmental Quality ◽  
Indoor Air ◽  
Building Design ◽  
Energy Performance ◽  
Building Performance ◽  
Indoor Environmental Quality

Hospitals are controlled yet complex ecosystems which provide a therapeutic environment that promotes healing, wellbeing and work efficiency for patients and staff. As these buildings accommodate the sick and vulnerable, occupant wellbeing and good indoor environmental quality (IEQ) that deals with indoor air quality (IAQ), thermal comfort, lighting and acoustics are important objectives. As the specialist nature of hospital function demands highly controlled indoor environments, this makes them energy intensive buildings due to the complex and varying specifications for their functions and operations. This paper reports on a holistic building performance evaluation covering aspects of indoor air quality, thermal comfort, lighting, acoustics, and energy use. It assesses the performance issues and inter-relationships between IEQ and energy in a new building on a hospital campus in the city of Bristol, United Kingdom. The empirical evidence collated from this case study and the feedback received from the hospital staff help identify the endemic issues and constraints related to hospital buildings, such as the need for robust ventilation strategies in hospitals in urban areas that mitigate the effect of indoor and outdoor air pollution and ensuring the use of planned new low-carbon technologies. Whilst the existing guidelines for building design provide useful instructions for the protection of hospital buildings against ingress of particulate matter from outdoors, more advanced filtration strategies may be required to enact chemical reactions required to control the concentration levels of pollutants such as nitrogen dioxide and benzene. Further lessons for improved performance in operation and maintenance of hospitals are highlighted. These include ensuring that the increasingly available metering and monitoring data in new buildings, through building management systems, is used for efficient and optimal building operations for better IEQ and energy management. Overall, the study highlights the need for an integrated and holistic approach to building performance to ensure that healthy environments are provided while energy efficiency targets are met.

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.

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