Search results

Poor indoor air quality in schools is a worldwide challenge that poses health risks to pupils and teachers. A possible response to this problem is to modify ventilation. Therefore, the purpose of this paper is to pilot a process of generating alternatives for ventilation redesign, in an early project phase, for a school to be refurbished. Here, severe problems in indoor air quality have been found in the school.

Ventilation redesign is investigated in a case study of a school, in which four alternative ventilation strategies are generated and evaluated. The analysis is mainly based on the data gathered from project meetings, site visits and the documents provided by ventilation and condition assessment consultants.

Four potential strategies to redesign ventilation in the case school are provided for decision-making in refurbishment in the early project phase. Moreover, the research presents several features to be considered when planning the ventilation strategy of an existing school, including the risk of alterations in air pressure through structures; the target number of pupils in classrooms; implementing and operating costs; and the size of the space that ventilation equipment requires.

As this study focusses on the early project phase, it provides viewpoints to assist decision-making, but the final decision requires still more accurate calculations and simulations.

This study demonstrates the decision-making process of ventilation redesign of a school with indoor air problems and provides a set of features to be considered. Hence, it may be beneficial for building owners and municipal authorities who are engaged in planning a refurbishment of an existing building.

Exposure to poor indoor air in refurbished buildings is a matter of health concern due to the growing concentrations of various contaminants as a result of building airtightness without amendment of ventilation, or the use of building materials such as glue, paint, thinner and varnishes. Recent studies have been conducted to measure indoor air pollutants and assess the health risks affecting the quality of life, productivity and well-being of human beings. However, limited review studies have been recently conducted to provide an overview of the state of knowledge. This study aims to conduct a scoping review of indoor air quality (IAQ) in the context of refurbished or energy-retrofitted buildings.

A systematic screening process based on the PRISMA protocol was followed to extract relevant articles. Web of Science, Scopus, Google Scholar and PubMed were searched using customised search formulas. Among 276 potentially relevant records, 38 studies were included in the final review covering a period from 2015 to 2022.

Researchers mapped out the measured compounds in the selected studies and found that carbon dioxide (CO₂) (11%) and total volatile organic compounds (11%) were among the most commonly measured contaminants. Two trends of research were found including (1) the impact of ventilative properties on IAQ and (2) the impact of introducing building materials on IAQ.

The contribution of this study lies in summarising evidence on IAQ measurements in refurbished buildings, discussing recent advancements, revealing significant gaps and limitations, identifying the trends of research and drawing conclusions regarding future research directions on the topic.

Poor indoor air quality (IAQ) contributing to occupants’ health symptoms is a universal, typically ventilation-related, problem in schools. In cold climates, low-cost strategies to improve IAQ in a naturally ventilated school are rare since conventional methods, such as window opening, are often inappropriate. This paper aims to present an investigation of strategies to relieve health symptoms among school occupants in naturally ventilated school in Finland.

A case study approach is adopted to thoroughly investigate the process of generating the alternatives of ventilation redesign in a naturally ventilated school where there have been complaints of health symptoms. First, the potential sources of the occupants’ symptoms are identified. Then, the strategies aiming to reduce the symptoms are compared and evaluated.

In a naturally ventilated school, health symptoms that are significantly caused by insufficient ventilation can be potentially reduced by implementing a supply and exhaust ventilation system. Alternatively, it is possible to retain the natural ventilation with reduced number of occupants. The selected strategy would depend considerably on the desired number of users, the budget and the possibilities to combine the redesign of ventilation with other refurbishment actions. Furthermore, the risk of poorer indoor air caused by the refurbishment actions must also be addressed and considered.

This study may assist municipal authorities and school directors in decisions concerning improvement of classroom IAQ and elimination of building-related symptoms. This research provides economic aspects of alternative strategies and points out the risks related to major refurbishment actions.

Since this study presents a set of features related to indoor air that contribute to occupants’ health as well as matters to be considered when aiming to decrease occupants’ symptoms, it may be of assistance to municipal authorities and practitioners in providing a healthier indoor environment for pupils and teachers.

This study aims to establish the relationship between indoor environmental quality and residential mobility in student housing in Ghana.

Using multiple regression and exploratory factor analysis through post occupancy evaluation, 26 indoor environmental quality (IEQ) indicators were explored among 1,912 students living in Purpose-Built off-campus university housing in Northern Ghana.

The study established a negative relationship between indoor environmental quality and residential mobility among student housing in Northern Ghana. Residential mobility is primarily attributed to the dissatisfaction with thermal and indoor air quality.

The negative relationship affects vacancy and rental cashflows for property investors. Also, understanding local environmental conditions can influence future student housing design and enhance thermal and indoor air quality.

The authors contribute to studies on indoor environmental quality in student housing. In addition, establishing the relationship between indoor environmental quality and residential mobility in tropical African regions is novel.

Accurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.

Fifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.

The eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.

The findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.

Direct measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

New Zealand’s historical housing stock comprises largely single-storey detached houses, characterised by poor winter comfort with high air infiltration. Challenges with affordability and land use are shifting New Zealand’s housing stock towards double-storey, conjoined medium-density housing (MDH). Reduced external surfaces in this typology should reduce winter heat loss and infiltration, improving winter comfort and health. New concerns arise, however, regarding summertime overheating and poor indoor air quality.

A field study was undertaken where temperature, humidity, airtightness, particulate matter (PM) and total volatile organic compounds (TVOC) were measured in two unoccupied, newly built double-storey, conjoined houses, for several weeks over summer.

The reduced surface area of this typology did not reduce infiltration and demonstrated significant periods of overheating. Internal PM concentrations generally exceeded outdoor concentrations but did not exceed annual average outdoor PM10 guidelines of 20 µg m-3. Infiltration factors (Finf) were closer to more traditional houses. TVOC readings varied widely, but frequently exceeded international guidelines.

The small sample limits the applications of conclusions more widely. Recommendations to investigate a wider sample in different locations with more detailed VOC analysis over all seasons are made.

Improvements to internal environments cannot be guaranteed by housing typology changes alone and must still involve thoughtful environmental design.

Housing typology changes may not improve internal living environments.

A move to the new MDH typology may not achieve expectations of airtightness and thermal improvement. New challenges arise from significant overheating and high TVOC levels, which may lead to new negative health effects.

Schools should be adequately built and operated to protect students' health. Green building rating systems, including Leadership in Energy and Environmental Design (LEED), assist the construction industry in improving both the resource efficiency and indoor environmental quality of its buildings. Construction professionals may waive some green modifications and available optional credits due to their high costs or construction complexities. This study investigates whether cost-effective green modifications can adequately address the student health.

In an effort to identify how school projects in Dubai, UAE prioritized LEED credits related to occupant well-being, the study identified eight LEED credits (called “Health and wellbeing” credits). Cost data from a sample of nine Dubai schools were used to develop an indicator, named the Feasibility Index Score (FIS), to quantify the attractiveness of LEED credits based on their cost and implementation complexity. Physical measurements taken from the sample schools give a window into current indoor environmental quality (IEQ) conditions of schools in the local region, while FIS provides insight into potential financial barriers towards improving these conditions.

The authors identified eight “Health and wellbeing” credits, which may net up to 14 points or 13% of all possible LEED points. Despite this, assessments of the sample schools revealed that six of the “Health and wellbeing” credits exhibited relatively low FIS values. This may cause these credits to be waived when lower tiers of LEED certifications are desired.

A sample of nine schools was chosen for this research; further investigation using a greater sample size is recommended.

The paper's IEQ assessment indicates the importance of health-related credits and suggests implementing them regardless of their FIS.

This paper recognizes the importance of providing more weight to credits that directly impact the health of occupants, particularly when upgrading existing structures.

This paper describes a new proactive approach for facility managers to assess and manage complaints of “sick buildings”.

The assessment of the “sick building” syndrome problem is multifaceted and should include both objective data such as those collected and analyzed by industrial hygienists, and subjective data such as occupant perception measurements, usually gathered by surveys. The data for this research, both objective and subjective, were provided on a wide variety of office buildings and were analyzed using an artificial neural‐network based model.

Current literature on the subject suggests that the cause of poor indoor environments involves many variables interacting in an unlimited number of combinations. Using a blended definition of a narrowly defined “sick building”, a framework for a decision‐making support system for facility managers is provided.

The data collection was limited to Southeastern US commercial office buildings, but the model has global applicability.

Recommendations are presented to help facility managers better understand the complex nature of the indoor environment based on this research.

This research and data analysis can be tailored to and is applicable to any building type.

This study seeks to investigate the usefulness of occupant acceptance as a preliminary screen measure for offices' indoor air quality (IAQ). An effective alert indication of IAQ problems of a concerned indoor environment would help to promote good IAQ.

The study evaluates the hypothesis that the occupant dissatisfaction with the overall indoor environment provides an indication of IAQ problems. Hence, occupant dissatisfaction would be used as a screening parameter to identify problematic IAQ regarding some IAQ criteria in subsequent IAQ assessments. The hypothesis was tested with a database of regional cross‐sectional measurement in 490 offices within Hong Kong.

The occupants' dissatisfaction with the indoor environmental quality (IEQ) was correlated with the IAQ assessment results of nine IAQ assessment parameters regarding some IAQ criteria for air‐conditioned offices. At certain screening levels of predicted IEQ dissatisfaction, the performance of the proposed screening tool, indicating unsatisfactory office IAQ, was evaluated in terms of the test sensitivity, specificity, predictive values and Yule's Q statistics. The results showed that occupants' response to the indoor environment produced indications of unsatisfactory IAQ regarding the requirement of an “Excellent” office.

The subjective feelings of occupants are capable of identifying marked indoor environmental problems, but cannot identify the “marginal” IAQ problem cases.

The study shows the usefulness of using occupant acceptance to identify the unrecognized IAQ problems for air‐conditioned office environment. Using the identification model developed in the study, all the suspected cases were associated with a high chance of IAQ dissatisfaction and subsequent IAQ assessments were thus recommended.

The paper proposes a new identification method to identify the unrecognized IAQ problems which may indicate unsatisfactory IAQ. Also, the occupants' responses on the indoor environment are quantified.