Good Indoor Environmental Quality Research Articles

Environmental controls of air-conditioned noise with the aid of the Psychoacoustics Perception Scale (PPS)

It is known that an air-conditioning system is an essential component of modern buildings for maintaining good indoor environmental quality. However, the adverse effect due to air-conditioned noise can offset its benefits. Although several noise indices such as Noise Criteria (NC), Noise Rating (NR), Room Criteria (RC), and A-weighted equivalent continuous sound pressure level (LAeq) have been developed to assess the acceptability of indoor noise environments, the noise feature of the environments and its psychological impacts on the occupants are not comprehensively evaluated. Psychoacoustics Perception Scale (PPS) is a psychometric tool to assess the psychological impacts about general judgment (Evaluation, E), sensitivity to the magnitude (Potency, P), and sensation of the temporal and spectral compositions (Activity, A) of noise on occupants. This study aimed to evaluate the air-conditioning building environments by using the traditional noise indices, psychoacoustic metrics, and the PPS. The significant correlations were found between the objective and subjective data. The results of the study provided the useful knowledge on future designs of the environmental controls of air-conditioned noise.

Prediction of psychological impacts of noise from ventilation systems

Air-conditioning ventilation systems are essential for maintaining good indoor environmental quality. However, the noise generated by these systems can have negative psychological impacts on occupants, such as dissatisfaction, discomfort, disturbance, and unacceptability. This problem cannot be solved simply by reducing the noise level. With the help of a valid, reliable, and applicable psychometric tool called the psychoacoustics perception scale (PPS), the psychological impacts of the noise on human general judgment (Evaluation, E), sensitivity to the magnitude (Potency, P), and sensation of the temporal and spectral compositions (Activity, A) of sounds can be quantified. A holistic sound quality assessment was proposed to cover the objective assessments of traditional indoor criteria and acoustic metrics, as well as subjective assessment using the PPS. The correlations found between the objective characteristics of the noise from ventilation systems, the PPS scores, and the occupants’ cognitive performance can extend traditional noise level prediction to the prediction of psychological impacts of air-conditioned environments. This advanced knowledge of noise prediction will help acoustic professionals in the design of teaching courses in acoustics, noise, and vibration control, as well as in building services engineering, and throughout the built environment.

INFLUENCE OF ENERGY EFFICIENCY RENOVATION ON INDOOR CLIMATE

The buildings of the 1960s are not designed for today’s conditions and sustainable building standards. One of the solution strategies is renovation, which is not only for energy conservation but also for quality-of-life improvement. However, achieving both factors at once is a challenge, mostly from a financial standpoint. For public establishments, their priority is on energy efficiency retrofits which in return could push the indoor environmental quality (IEQ) to the edge of the comfort zone. IEQ is correlated to the health, comfort, and performance of users according to previous studies. This paper presents a case study of university buildings that underwent an energy-efficient renovation, including the replacement of windows and the installation of walls and roof insulation and mechanical extract ventilation systems. The objective is to analyze if the target energy consumption is achieved while maintaining a good IEQ during the heating period. Using t-test statistics on in-situ measurements of the before and after renovations, the results have shown three important findings. One, the total energy consumption has been reduced by 67%. Two, the t-test shows a significant difference between before and after states, with temperature decreased, and CO2 level increased. Three, a higher CO2 concentration is due to a faulty ventilation control that provides half less of the initial design airflow rate to meet a healthy standard. Overall, both temperature and CO2 rates remain in acceptable ranges despite the variation, but it is crucial to evaluate the HVAC controls after the renovation for safety reasons.

The prevalence of hoarseness among health care professionals: time trends and effect of remediation in working conditions in 2007–2018

PurposeThe purpose of this study was to investigate time trends in the prevalence of hoarseness among health care professionals in primary health care units (PHC) and in hospitals from 2007 to 2018. Moreover, purpose was to discover potential indoor environmental quality (IEQ) risk factors as well as to determine the effect of the remediation of the indoor air problems on the prevalence of hoarseness.MethodsThe health status was collected from all employees in these units/hospitals (N = 1564/1199) with questionnaires and the follow-ups were carried out as an open cohort. Based on building condition inspections, buildings were classified to be an “exposed” or “reference” buildings by third-party experts. The before and after remediation results were compared to reference buildings.ResultsDuring follow-up, hoarseness has not increased in those PHC units with good IEQ. In the pilot study, the prevalence of hoarseness in non-exposed reference building was 5.9%, and it stayed approximately at the same level throughout the follow-up. Whereas in buildings with an IEQ problem the prevalence of hoarseness varied between 16.2 and 36.1% and it decreased to 11.4% after the remediations. In a large hospital with severe IEQ problems, the prevalence of hoarseness was 39.1%, and in hospital buildings with a milder exposure 23.3%. The most important risk factors for hoarseness were asthma, allergic rhinitis and IEQ problems.ConclusionA good indoor environment and the remediation of damaged buildings seem to promote a better condition of the voice in health care workers.

Energy renovation of the multi-residential historic building after the Zagreb earthquake – Case study

Historic buildings represent our cultural heritage and identity. Due to their age and building tradition, they are extremely vulnerable to seismic excitations, as confirmed by the recent earthquake in the city of Zagreb. In addition, historic buildings are among the buildings with the worst energy performance and very low indoor comfort. In the scope of this paper, the seismic and energy integrated approach is applied to a typical multi-residential building in Zagreb historical downtown. The main focus of the paper is on building envelope energy efficiency measures. Different variants of thermal insulation (external and internal), secondary windows (maintaining existing ones vs. new efficient ones) and ventilation (natural vs. mechanical with heat recovery) are analysed in terms of building energy performance (3D level). Furthermore, replacement of existing technical systems and installation of RES are also considered. Moreover, the acceptability of the proposed retrofitting solutions for opaque elements is evaluated in terms of thermal bridges (2D level) and long-term hygrothermal performance (1D level). Finally, the results show that it is possible even for a 100-year-old building to meet the current national primary energy requirements for new buildings and provide good indoor environmental quality for occupants while respecting the cultural heritage.

Energy Efficiency in High-rise Office Buildings: An Appraisal of its Adoption in Lagos, Nigeria

High-rise office buildings are naturally energy-intensive as energy is required in large quantities to run modern building services and to power equipment needed for a hitch-free operation of the buildings. It was found in studied literature that maintaining good indoor environmental quality through air-conditioning, lighting and powering of office equipment contribute the most to an office building’s total energy consumption. Hence, over time, various strategies have been employed to reduce the intense energy demand in high-rise office buildings. This paper adopted the use of both literature review and case study methods. The paper identifies the key energy efficiency strategies that have been successfully deployed in high-rise office buildings using the literature review approach. Also, case studies were conducted on three relatively new high-rise office buildings in Lagos, Nigeria by evaluating them against the background of the best practices in energy efficiency. The study found that deployment of energy efficiency strategies in high-rise office buildings in the study area is still very low especially in the areas of building orientation, building envelope design and the use of renewable energy. However, the use of day-lighting techniques and sustainable lighting systems are quite prominent in the office buildings studied. The study underscores the need to make high-rise office buildings more sustainable through energy efficiency strategies across the whole building life cycle of design, construction, use and end of life.

Prediction of Indoor Environmental Quality Using a Regression Model for Educational Buildings in Hot Arid Climate: A Case Study in the Al-Najaf Technical Institute – Iraq

In hot climates, achieving a good indoor environmental quality (IEQ) in existing buildings is important especially with climate change challenges as future heat waves will increase in frequency, duration, and intensity. In educational buildings, there is much more focus on the IEQ parameters and the interactions among them that need to be in line with the continuously changing learning environment. This study assesses the IEQ parameters (represented by noise, temperature and humidity) at three selected campus areas (lecture rooms of an administrative department building (LR), main hall of a management department building (MH) and a central library building (CL)) at the Al-Najaf Technical Institute (NTI), Al-Najaf City, Iraq, for the period from May to December 2019. A statistical analysis using a multi-linear regression model was performed to determine the relationship between the selected IEQ parameters and explain the noise level behavior as a function of the temperature and relative humidity. The research indicated that the noise levels and temperature values exceeded the maximum standard limits in all buildings reflecting the displeasing sound and heating quality within the studied areas, while the readings for relative humidity within each building environment complied with standards. Moreover, for both LR and MH buildings (R2 ≥ 0.8, significance F ≤ 0.01), the noise values were satisfactorily modeled by temperature and relative humidity highlighting the interactions between temperature, humidity and noise under consistent conditions. However, the results for the CL building (R2 = 0.6, significance F = 0.1) showed no relationship between the IEQ parameters, highlighting the fact that this building is exposed to unsteady conditions (an irregular number of people using this building during the daytime) resulting in a high variation of data measurements. The current results demonstrate that detailed modeling can be helpful to predict IEQ parameters depending on other known parameters in buildings. The results of the predictive model aligned with the directly measured data. Therefore, its performance is equally effective, but with a significant reduction in cost and time consumed.

Performance investigation of a net-zero energy building in hot summer and cold winter zone

The net-zero energy building (NZEB) is spreading rapidly as an integrated solution to address energy saving and carbon emissions reduction in the building sector. However, few studies pay close attention to the operational performance of NZEBs as well as their life cycle impact on the environment. This study investigates the operational performance of NZEBs, analyzes the influence factors in achieving net-zero energy, and explores the pathway to reduce the building life cycle carbon emission via a case study conducted from March 2017 to February 2018 in the hot summer and cold winter climate zone of China. The one-year investigation results show that the case building, where energy-efficient technologies and renewable energy were integrated, achieved net-zero energy with good indoor environmental quality. Based on the investigation, influence factors in achieving net-zero energy were analyzed via DesignBuilder: the minimum area per capita was 42 m 2 /person under the circumstance of net-zero energy; when operational strategy was changed, the air-conditioning energy use reduction was less than 5%. Additionally, in order to achieve net-zero energy, an equation was proposed to estimate the area ratio of installed photovoltaic (PV) panels to that of the building roof, thereby providing guidance for NZEBs design. Furthermore, life cycle carbon emissions of the project were evaluated. Based on the foregoing results, it can be concluded that by increasing carbon offsets of the PV system appropriately, an NZEB can be transformed into a life-cycle zero-emission building. Moreover, it is necessary to mention that the life cycle carbon emissions of the PV system should be considered. • Efficient technology and renewable energy are integrated to achieve net-zero energy. • Indoor environment quality is kept within comfort range with low energy used. • Influence factors in achieving net-zero energy is analyzed. • A net zero-energy building can achieve zero emission throughout the life cycle. • Life cycle carbon emissions of PV system deserve consideration.

A Review on Indoor Environment Quality of Indian School Classrooms

The progress of Indoor Environmental Quality (IEQ) research in school buildings has increased profusely in the last two decades and the interest in this area is still growing worldwide. IEQ in classrooms impacts the comfort, health, and productivity of students as well as teachers. This article systematically discusses IEQ parameters related to studies conducted in Indian school classrooms during the last fifteen years. Real-time research studies conducted on Indoor Air Quality (IAQ), Thermal Comfort (TC), Acoustic Comfort (AcC), and Visual Comfort (VC) in Indian school classrooms from July 2006 to March 2021 are considered to gain insight into the existing research methodologies. This review article indicates that IEQ parameter studies in Indian school buildings are tortuous, strewn, inadequate, and unorganized. There is no literature review available on studies conducted on IEQ parameters in Indian school classrooms. The results infer that in India, there is no well-established method to assess the indoor environmental condition of classrooms in school buildings to date. Indian school classrooms are bleak and in dire need of energy-efficient modifications that maintain good IEQ for better teaching and learning outcomes. The prevailing COVID-19 Pandemic, Artificial Intelligence (AI), National Education Policy (NEP), Sick Building Syndrome (SBS), Internet of Things (IoT), and Green Schools (GS) are also discussed to effectively link existing conditions with the future of IEQ research in Indian school classrooms.

Determining the Impact of High Residential Density on Indoor Environment, Energy Use, and Moisture Loads in Swedish Apartments-and Measures for Mitigation

Recently, there has been an increase in apartments with a large number of inhabitants, i.e., high residential density. This is partly due to a housing shortage in general but also increased migration, particularly in suburbs of major cities. This paper specifies issues that might be caused by high residential density by investigating the technical parameters influenced in Swedish apartments that are likely to have high residential density. Interviews with 11 employees at housing companies were conducted to identify issues that might be caused by high residential density. Furthermore, simulations were conducted based on extreme conditions described in the interviews to determine the impact on the energy use, indoor environmental quality, and moisture loads. In addition, the impact of measures to mitigate the identified issues was determined. Measures such as demand-controlled ventilation, increase of a constant ventilation rate, and moisture buffering are shown to reduce the risk for thermal discomfort, mold growth, and diminished indoor air quality; while still achieving a lower energy use than in a normally occupied apartment. The results of this study can be used by authorities to formulate incentives and/or recommendations for housing owners to implement measures to ensure good indoor environmental quality for all, irrespective of residential density conditions.

Analysis of green building performance in cold coastal climates: An in-depth evaluation of green buildings in Dalian, China

This study described here evaluated certified green building projects in Dalian, a typical coastal city in a cold region of China, from 2008 to 2017. Of 16 surveyed cases in Dalian, 73% adopted a high-performance building envelope system. Energy-saving technologies were favored and demonstrated worthwhile economic benefits. In 80% of the cases high-performance green materials had been used. Resource-saving technologies also were widely adopted. In addition to analyzing all the data collected, the study under-took an in-depth analysis of one building. A representative three-star green public building in Dalian, China, was chosen as a case study for analyzing the energy consumption and operating performance. The study found that energy use intensity of the case-study building is 68.02 kW-hours per square meter per year(kWh/(m2・a)). It saves 44.14 kWh/m2・a compared with a conventional building in the same climate, thanks to its energy efficiency systems and integration of renewable energy. The water consumption of the building when operating was 0.41 cubic meter per square meter(m3/m2) per year, which is even lower than the design value. The case-study building also demonstrated good indoor environmental quality throughout different seasons. Finally, practical methods and suggestions were derived from evaluating and discussing effective technologies in the 16 buildings surveyed. The research led to recommendations for developing green buildings in cold and coastal climates. It also provides a substantial guidance for the energy-saving design of green buildings and the application of appropriate technologies in cold coastal cities.

Adaptation of Indoor Health and Comfort Criteria to Mitigate Covid-19 Transmission in the Workplace

The research discussed the application of indoor health and comfort criteria that needed to be reviewed to create good indoor environmental quality and reduce the transmission of the Covid-19 virus where people spent most of their time indoors. A confined area, which was poorly ventilated and reliant on air conditioning, helped transmit the Covid-19 virus easily as air recirculation was the main cause of office clusters. One of the categories of Greenship Interior Space, Indoor Health and Comfort (IHC), could be used as a guide for creating better indoor quality. The method used for the research was a systematic literature review to define, study, analyze, and classify all available research relating to adaptation of indoor health and comfort criteria to mitigate the transmission in the workplace. The results show the adjustment to IHC criteria in IHC 1-10, which focus on providing good air quality by introducing outside air, stopping air recirculation, reducing indoor user capacity, and reducing indoor biological and chemical pollutants. To illustrate the implementation of the new normal, Ciputra University workplace was being observed, as the findings of the results, some strategies that are in line with the objectives of IHC 1, IHC 2, and IHC 5. Adjustment of these criteria must be supported by implementing health protocols through basic hygiene routines, fitness screening, and maintaining physical distancing.

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

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.

Good indoor environmental quality (IEQ) and high energy efficiency in multifamily dwellings: How do tenants view the conditions needed to achieve both?

Sustainable housing that both creates good indoor environmental quality (IEQ) and avoids unnecessary energy use has proved difficult to realize. Renovations of multifamily houses provide an opportunity to find this balance. This study concerns whether tenants perceive that conditions for achieving sufficient IEQ with low energy use exist. Focus group interviews with 42 participants, in areas where the rents were in the lower range and included heating up to 21 °C, aimed to capture the tenants' perceptions of: IEQ and actions taken to regulate it; information and control; the connections between IEQ and energy use; and the role of the housing company. Good IEQ was crucial to interviewees, who described it as sufficient heat without draughts, ability to ventilate, and no disturbing sounds or smells. The main responsibility was attributed to the housing company, but daily regulation controlled by tenants. However, unclear interfaces between tenants and the systems that regulate IEQ make it difficult for tenants to act as a positive part of the system. Tenants did not link IEQ to energy use. A holistic view of the physical environment's affordances, including intuitive interfaces, could optimize the balance between good IEQ and energy use.

Developing an Indoor Environment Assessment Tool for Residential Buildings

The Indoor Environmental Quality (IEQ) describes an indoor space condition that the wellbeing and comfortability are provided for the users. Many researchers have highlighted the importance of adopting IEQ criteria, although they are not yet well defined in the Kurdistan region. However, environmental quality is not necessary for the contemporary buildings of the Kurdistan Region, and there is no measurement tool in the Region. This research aims to develop an IEQ assessment tool for the Kurdistan region using Mixed method methodology, both qualitative and quantitative. Therefore, a Delphi Technique was used as a method initially developed as systematic, interactive forecasting on a panel of experts. Thirty-five Delphi Candidates have reached an agreement on selecting the criteria for the IEQ, as Spss and a particular equation has used to find criteria weights. As a result, seven criteria with 22 indicators have been selected by expert ratings. A computer-based tool (KIEQA) has been created based on the scores selected by experts. Research results show that good IEQ is essential for interior design. It also offers a suitable indoor environment for users. This research has many significant advantages since it can raise awareness of issues of indoor environmental quality for architects, experts, and policymakers. Furthermore, to draw up an action plan for existing and new interior design projects in the Kurdistan Region. Future researches may concentrate on the correlation between IEQ criteria and to develop this tool regarding different building typologies.

Indoor environmental quality (IEQ) assessment of Nigerian university libraries: A pilot study

An indoor environmental quality (IEQ) assessment of academic libraries in Nigeria was conducted through objective measurements. The selected university libraries were Abubakar Gimba Library; Awwal Ibrahim Library; and Ibrahim Badamosi Babangida Library Complex. The libraries were evaluated under operating conditions and during their peak usage periods. Measurements of the main descriptors of good IEQ, including the acoustical, visual, and thermal comfort conditions were performed using portable IEQ meters. The methodology employed for the assessment of these IEQ descriptors followed prescriptions of international standards ASHRAE standard 55 and ISO 7730. To determine the time of the day in which the library buildings can achieve optimum IEQ, measurements were taken in the morning and afternoon. The results obtained were compared with reference values found in the international Standard CIBSE Guide A for adequate IEQ compliance of academic libraries. The findings of this study are expected to help in improving the IEQ of academic libraries in Nigeria and other parts of the world.

A novel methodology and new concept of structural dynamic moisture buffering for modeling building moisture dynamics

This paper presents a new methodology that takes a physical-statistical approach to dynamically model indoor air humidity and moisture transport in building structures. A new concept, structural dynamics moisture buffer capacity (SDMBC), is introduced that improves on the most commonly used moisture buffer measure. The paper proposes and experimentally proves several novel hypotheses regarding the linear relationship between model variables, great simplifying the derivation of the model equations. The resulting dynamic model is simple, efficient, and easy-to-implement. Furthermore, full-scale experiments using three identical wooden test houses were built to support the development of the dynamic model. Airflow rates were calibrated and verified by experiment. The results of this study establish the practicality of this new modeling methodology which can aid researchers in constructing improved simulation models and designers in selecting building materials to optimize indoor humidity, minimize energy consumption, and provide good indoor environmental quality.

Environmental and sustainable aspects of green building: A review

Public and scientific focus of interest on climate changes, population increase, rapid urbanization is rising day by day. Thus, increased demand for green buildings that reduces negative impacts, and can creates positive impacts on climate, natural environment and sustainable development is a new topic. Green buildings must be not only eco-friendly (efficiently use energy, water, and other resources, use renewable energy, reduce pollution and waste, enable reuse and recycling, have good indoor environmental quality, use of materials that are non-toxic, ethical and sustainable) but also function as the key part to provide a comfortable working/living environment for human activities and improve quality of life. It is realised that green buildings as a worldwide response to raise awareness of the role of human activity in global climate changes, with maximum expression in Leadership in Energy and Environmental Design (LEED) Certification and its five basic requirements: Sustainable Space (SS), Materials and Resources (MR), Energy and Atmosphere (EA), Environmental Quality (EQ), and Water Efficiency (WE).The aim of this study is to review the environmental and sustainable aspects of green buildings. For this goal, environmental and sustainable aspects of green building including its origin, concept, eco-friendly properties, benefits, tools, rating systems, certifications are given and discussed in detail in this study.

Analysis of Mould Growth Causes in Higher Education Library Indoor Environment

This paper presents an analysis of mould growth causes that be found in an indoor library environment. The visual inspection had been conducted to identify visible mould in the indoor library environment. Three higher education institution libraries in Malaysia were selected as a case study. The identified mould species on the site were analysed using mould growth germination factors and possible causes that related to the growth. The result confirmed mould species such as Aspergillus, Penicillium, Stachybotrys’s identified as a common mould growth found in the three library buildings. The analysis of mould growth causes is important for this study as is to confirm the relationship with the mould found in this building which may result in adverse health impact, environment, material and archive in the library. The result also can become guidelines and best practices for library management regarding good indoor environmental quality.

A Wireless Gas Sensor Network to Monitor Indoor Environmental Quality in Schools.

Schools are amongst the most densely occupied indoor areas and at the same time children and young adults are the most vulnerable group with respect to adverse health effects as a result of poor environmental conditions. Health, performance and well-being of pupils crucially depend on indoor environmental quality (IEQ) of which air quality and thermal comfort are central pillars. This makes the monitoring and control of environmental parameters in classes important. At the same time most school buildings do neither feature automated, intelligent heating, ventilation, and air conditioning (HVAC) systems nor suitable IEQ monitoring systems. In this contribution, we therefore investigate the capabilities of a novel wireless gas sensor network to determine carbon dioxide concentrations, along with temperature and humidity. The use of a photoacoustic detector enables the construction of long-term stable, miniaturized, LED-based non-dispersive infrared absorption spectrometers without the use of a reference channel. The data of the sensor nodes is transmitted via a Z-Wave protocol to a central gateway, which in turn sends the data to a web-based platform for online analysis. The results show that it is difficult to maintain adequate IEQ levels in class rooms even when ventilating frequently and that individual monitoring and control of rooms is necessary to combine energy savings and good IEQ.