Comfort Standards Research Articles

Ventilation Performance of Air Duct in Double Loaded Corridor Building: A Case Study

Buildings with double-loaded corridor types are often found in Indonesia and generally function as offices or lecture rooms. This type of building is popular because of its efficient circulation path to accommodate the movement of occupants. However, a wall separating the room from the corridor makes it impossible to put windows to implement a cross-ventilation system due to acoustic problems. Hence, to achieve indoor thermal comfort, this type of building relies on using an air conditioning (AC) system. However, with the WHO's call to reduce the use of AC during the COVID-19 pandemic, it is necessary to evaluate cross-ventilation in double-loaded corridor buildings to meet comfort standards while still preventing acoustic problems due to noise from corridors and other spaces. The study proposes a new natural ventilation system using air ducts placed above the corridor ceiling to create cross-ventilation in lecture buildings. The E-ITERA building was chosen as a case study in this research. The building has a glass facade with several small windows that can be opened outside. The corridor of this building is designed with openings at both ends, allowing for direct connection to the outside air. The walls facing the passage have a single door and four small ventilations on the aisle's upper side. Simulations were carried out in two classrooms on the 3rd floor using CFD (Computational Fluid Dynamics) software. Experiments were carried out to change the size of the air duct and the size of the ventilation on the wall that leads to the corridor. The results showed that the air duct was able to create cross-ventilation. Ventilation performance is improved when the WWR air duct is the same as the WWR window. The highest air velocity in the centre of the room is 0.6 m/s. Doi: 10.28991/CEJ-2023-09-10-06 Full Text: PDF

Comparison of FEA and SEA methods for predicting railway-induced vibration propagation through over-station developments

The design process for Over-Station Developments (OSDs) includes consideration of the potential impacts of railway-induced vibrations to ensure that structure-borne noise and occupant comfort standards are maintained during railway operations. Should an OSD be identified as sensitive to railway operational structure-borne noise or vibration impacts, the inclusion of adequate track vibration isolation measures becomes essential for mitigation. This paper presents a comparative study of two methodologies for predicting vibration propagation through structures and consequent structure-borne noise levels—Finite Element Analysis (FEA) and Statistical Energy Analysis (SEA). Specifically, this study provides an indication of the range of predicted results and emphasizes the computational efficiency and scalability of these methods when determining track isolation requirements for structures.

Thermal comfort and productivity in a workplace: An alternative approach evaluating productivity management inside a test room using textual analysis

One of the issues in building research is the design of environments providing high standards of comfort and increasing the productivity of occupants and workers. However, the subjectivity related to perception and comfort, and the difficulty in assessing productivity are two critical aspects widely reported in the literature. In this work, the new Methodology for the Analysis of Computerized Textual Data (M.A.D.I.T.) has been applied to the study of productivity. It investigates the use of Natural Language, considered as the medium through which humans attribute sense to the situations they are involved – in this case, a working reality. The new strategy tries to fill the gap on the difficult quantification of productivity management due to the bias linked to the personal assessment criteria, that can hardly be predicted and evaluated. Experimental tests have been carried out in a test room to observe how people react and interact with a typical office workplace, with fixed and controlled environmental parameters, thus focusing on how individual perceptions, evaluations and preferences can be used by potential workers to manage their productivity. The research, while providing further evidence that comfort level does not seem to provide a direct and exclusive factor of productivity, it also offers productivity management indicators, which can be used not only to evaluate work activity, but also to orient it towards a higher level of efficiency and effectiveness.

A multi-objective reinforcement learning approach for furniture arrangement with optimal IEQ in multi-occupant offices

Indoor Environmental Quality (IEQ) concerns several aspects of environmental comforts, such as thermal, visual and acoustics comfort. In particular, IEQ plays a relevant role in workers’ satisfaction since it strongly influences health, well-being, and productivity. Specifically, it has been demonstrated that the furniture configuration in working spaces affects the occupant’s comfort perception. Nevertheless, IEQ has been either neglected or partially addressed in the context of interior design. The contribution of this paper is to introduce a novel method for furniture layout optimisation in terms of IEQ requirements in multi-occupant offices. In particular, we explore the furniture arrangement task as a Multi-Objective Markov Decision Process (MOMDP), which is solved by a reinforcement learning (RL) agent. The goal is to determine optimal workstation positions that maximise workers’ IEQ satisfaction and functional aspects of working spaces under analysis. Firstly, we formulated the furniture layout task as a MOMDP problem by defining reward functions in terms of thermal, acoustics and visual comfort. Then, we train the RL agent to produce optimal/suboptimal layout patterns through a Q-learning-based algorithm. We conducted experiments in two different offices. The experimental results demonstrated that the proposed multi-objective RL approach is able to determine optimal furniture arrangements that provide a balance among office occupants in terms of IEQ satisfaction. Moreover, numerical results show that the proposed approach can be a valuable tool for evaluating the conformity to the environmental comfort standard of working environments during the furniture layout design phase instead of applying corrections during the post-occupancy evaluation.

Numerical investigation of indoor thermal comfort and air quality for an office equipped with corner impinging jet ventilation

ABSTRACT This study investigates the feasibility of using only corner impinging jet ventilation (CIJV) for heating and cooling a medium-sized office space with two occupants while maintaining adequate indoor thermal comfort and air quality compared to traditional mixing ventilation systems. This study examines what impact various outdoor temperatures, ranging from −15°C to 25°C, have on an office environment in terms of indoor thermal comfort and air quality. Three different workspace positions were evaluated. The results show that the CIJV system meets the ASHRAE thermal comfort standards for all three positions. In terms of indoor air quality, CIJV performs better than traditional mixing systems, with improved mean age of air and ACE values. This study concludes that CIJV can be used both close and far away from the supply inlets and still provide adequate indoor thermal comfort and air quality during both cooling and heating season.

Laminated glass slabs design challenges: dynamic identification of a fractured pedestrian walkway

AbstractDesign codes provide requirements for traditional slabs to ensure both safety levels and in‐service functionality criteria. However, for existing structures, an initial diagnostic knowledge phase is essential to characterize the actual health state, e.g. based on structural health monitoring (SHM) with operational modal analysis (OMA) techniques. Considering recent advancements in glass as a structural material, laminated glass (LG) slabs are increasingly used in constructions and are mostly designed to account for the intrinsic brittleness and limited tensile resistance of glass. The latest pre‐code CEN/TS 19100:2021 is paving the road for an imminent future Eurocode 10 dedicated to providing new standards for the innovative use of structural glass. In the current study, a brief review of the design challenges of working with structural glass is presented. After that, the authors provided a simple experimental dynamic identification example of an LG pedestrian walkway located in the Basilica of Aquileia, Trieste (Italy). Specifically, the fundamental mode was compared to a healthy and a partially fractured LG slab. Functionality aspects related to comfort standards with respect to in‐service vibration issues are also detailed.

Overall and local intrinsic clothing insulation using thermal manikin: Impact of methods employed and postures

Development of multi-node thermoregulation models with local clothing insulation as an indispensable input parameter enables distinguishing the effects of spatial and temporal changes in the thermal environment around the human body. However, the current research on local clothing insulation lags compared with multi-node thermoregulation models, affecting model prediction accuracy. The effects of the determination methods and posture on the overall and local intrinsic clothing insulation remain unknown. Therefore, in this study, the overall and local intrinsic clothing insulation values for seven typical clothing ensembles in standing and sitting postures were determined using four different methods that included thermal manikin (TM) experiments and thermal comfort standards. The results showed that (1) the overall intrinsic clothing insulation Icl differed slightly across the methods, whereas the local clothing insulation Icl,i differed substantially across the methods; (2) the overall intrinsic clothing insulation Icl for the sitting posture was 15% lower than that of the standing posture, whereas the difference in the local intrinsic clothing insulation Icl,i for the standing and sitting postures was only statistically significant at the pelvis and thigh; and (3) the local intrinsic clothing insulation Icl,i differed significantly over different body segments, and the largest Icl,i was 2.7 and 3.2 times the smallest Icl,i for the standing and sitting postures, respectively. Therefore, methods employed along with the posture affected the results of both overall and local intrinsic clothing insulation. The findings are effective in modeling sensible heat loss through clothing and contribute to improving the prediction accuracy of multi-node thermoregulation models.

Ride comfort and segmental vibration transmissibility analysis of an automobile passenger model under whole body vibration

The examination of seated occupants’ ride comfort under whole-body vibration is a complex topic that involves multiple factors. Whole-body vibration refers to the mechanical vibration that is transmitted to the entire body through a supporting surface, such as a vehicle seat, when traveling on rough or uneven surfaces. There are several methods to assess ride comfort under whole-body vibration, such as subjective assessments, objective measurements, and mathematical models. Subjective assessments involve asking participants to rate their perceived level of discomfort or satisfaction during the vibration exposure, typically using a numerical scale or questionnaire. Objective measurements include accelerometers or vibration meters that record the actual physical vibrations transmitted to the body during the exposure. Mathematical models use various physiological and biomechanical parameters to predict the level of discomfort based on the vibration data. The examination of seated occupants ride comfort under whole-body vibration has been of great interest for many years. In this paper, a multi-body biomechanical model of a seated occupant with a backrest is proposed to perform ride comfort analysis. The novelty of the present model is that it represents complete passenger by including thighs, legs, and foot which were neglected in the past research. A multi-objective firefly algorithm is developed to evaluate the biomechanical parameters (mass, stiffness and damping) of the proposed model. Based on the optimized parameters, segmental transmissibilities are calculated and compared with experimental readings. The proposed model is then combined with a 7-dofs commercial car model to perform a ride comfort study. The ISO 2631-1:1997 ride comfort standards are used to compare the simulated segmental accelerations. Additionally, the influence of biomechanical parameters on most critical organs is analyzed to improve ride comfort. The outcomes of the analysis reveal that seated occupants perceive maximum vibration in the 3–6 Hz frequency range. To improve seated occupants' ride comfort, automotive designers must concentrate on the pelvis region. The adopted methodology and outcomes are helpful to evaluate protective measures in automobile industries. Furthermore, these procedures may be used to reduce the musculoskeletal disorders in seated occupants.

Excessive Noise in Neonatal Units and the Occupational Stress Experienced by Healthcare Professionals: An Assessment of Burnout and Measurement of Cortisol Levels.

Excessive noise in the work environment has been associated with extra-auditory symptoms, which can have harmful long-term effects on individuals. The purpose of this study was to identify noise levels in neonatal intensive care units and investigate their impact on the occurrence of stress among healthcare professionals, using cortisol levels as a biomarker for Burnout Syndrome. This descriptive, observational, and cross-sectional study was conducted in four public teaching hospitals in Fortaleza, Ceará, Brazil. Sound pressure levels in the environment were measured, and questionnaires were administered to collect sociodemographic data and assess perceptions of the work environment and Burnout symptoms. Saliva samples were collected at the beginning and end of work shifts for cortisol quantification. The average sound pressure ranged from 59.9 to 66.4 dB(A), exceeding the recommended levels set by Brazilian and international legislation. Among the 256 participants, the average age was 39.4 years, with 95% being female. The majority (70.9%) were nurses, and 22.7% were physicians. There was no significant association found between noise and Burnout Syndrome, nor with changes in cortisol levels. However, a significant association was observed between the perception of excessive noise and the sensation of a stressful work shift (p = 0.012). All evaluated professionals displayed symptoms of Burnout. The high sound pressure levels indicated that the assessed environments did not meet the recommended standards for acoustic comfort, and this was associated with the participants' perception of stressful work shifts. While Burnout symptoms were evident in our participants, it was not possible to confirm a correlation with high noise levels.

Experimental and numerical investigations on radiant floor heating system integrated with macro-encapsulated phase change material

Macro-encapsulated phase change material (PCM) with PCM as core and polymer as shell is reported an extremely stable energy storage medium in radiant floor heating system (RFHS). Herein, RFHS-based rooms with and without macro-encapsulated PCM are built, and the comfort and economy of the corresponding rooms are evaluated. Experimental results show that the room with macro-encapsulated PCM has longer thermal comfort time and slighter temperature deviation than without, according to the comfort standard. Then, a 3D unsteady heat transfer model is established and corrected by experimental data. Results show that macro-encapsulated PCM as temperature buffer layer regulates the heating-cooling rate of room and forms a semi-elliptic air radiant temperature zone. The room with macro-encapsulated PCM has lower daily electricity cost (c‾) of 0.2595 CNY/day and higher comfort time ratio of inside air (t‾) of 80.88%, decreased by 36.71% and increased by 15.43% than without, respectively. The thermal conductivities of shell and core of macro-encapsulated PCM are orthogonally optimized to be respectively 0.25 and 1.00 W/(m·K), with lowest c‾ (0.2480 CNY/day) and higher t‾ (85.47%), decreased by 4.43% and increased by 5.67% than pre-optimization. When the ambient temperature changes within −10∼10 °C, the input power of the room with macro-encapsulated PCM is orthogonally optimized to save c‾ by 35.91%∼39.39% than without.

Improving Indoor Air Quality through Standardization

Human beings experience a large fraction of their exposure to air pollutants in indoor environments. Air pollution is a large environmental health risk, and exposure to ambient air pollution and indoor air pollution contribute equally to the total number of fatalities worldwide. Although legislative authorities have established limit values for ambient outdoor air and stack emissions, there are inconsistent and variable national and regional limit values for gaseous substances and airborne particulate matter in the built environment (schools, homes, healthcare facilities, offices, and other public spaces). This lack of regulation is unsurprising, because indoor spaces are characterized by complex air chemistry, and their construction materials and types of activities vary significantly. The current understanding of indoor pollutants, including short-lived oxidants, degradation of VOCs, particle formation, and particle composition, is incomplete. It is necessary to identify and assess emerging pollutants and their toxicity, and to consider new consumer products and green construction materials and their impact on indoor air quality (IAQ). Learning from IAQ surveys and audit protocols, research methodologies should be regularized for cross-research comparisons. Some indoor air quality guidance and standards have been written, and several more are in development, with the international ISO 16000 series of indoor standards leading the way for improving indoor air data quality. The WHO has established some ambient air limit values which can mostly be translated into indoor limit values. The built environment needs to harmonize energy efficiency, thermal comfort and air quality standards and guidance. In this review, we discuss the next steps for improving international, regional and national standards and guidance, leading to better and more complete indoor air quality regulations.

Energy Consumption Optimisation of Emergency Shelters for Ukrainian War Refugees

The paper deals with optimisation of energy consumption of emergency shelters (tiny houses) for Ukrainian War refugees. Significant amount of Ukrainian citizens lost their homes or were forced to leave their properties. These refugees overcrowd the rest of the country and bring huge problems with accommodation and inclusion into existing communities. Accommodation in schools or gyms is just temporary solution with another unpleasant influence on the society. It is necessary to construct new quarters or communities using cheap but energy very efficient constructions. Several variants of tiny house with various equipment features and living or comfort standard are being discussed and compared. These studies are based on real project realised between Ukrainian non-government organisation Synergy and German development agency weChange. Main goal of this research is consumption optimisation of not particular single shelter but rather of large community of shelters containing hundreds or thousands units called shelter city. The tiny houses itself are designed according to passive solar systems standards and with accent to minimal purchasing costs and operational energy needs. Second important requirement is strong optimisation of shelter’s load chart to significantly decrease influence of the shelter city to power grid connection point. Both tasks are important because the Russian attack against Ukraine brings new tasks for power engineering sector. Electricity production, transmission, distribution and consumption must face new challenges. Nowadays more than 35 % of critical infrastructure is being damaged. Remaining infrastructure would be more overloaded, if new customers are connected without energy needs optimisation.

Lighting characterization of an Italian beginning twentieth-century school building

Nowadays, visual comfort in classrooms is considered crucial for the quality of students' learning processes. In Italy (1888 and 1901), many educational buildings, which constitute a cluster of historic school buildings, were built following specific national regulations. These buildings are characterized by the careful design of the classrooms both in relation to the orientation and their size. Among the design criteria, educational buildings structures had taken into account the orientation of the facades, as well as the arrangement and size of windows and other light inputs The study presented in this paper is aimed at evaluating if these educational buildings, designed according to ancient rules, are able to meet today's standards of visual comfort. With this purpose, the assessment of lighting levels, luminance distribution, average daylight factor, and daylight autonomy (DA) was carried out for all classrooms for a case study, typologically representative of this school buildings' cluster. The daylight analysis showed that most classrooms were subject to glare and lack of uniformity of illumination, while in other environments low values of illuminance levels were found. However, it is believed that a lighting refurbishment, respectful of the cultural value of these historic school buildings, can be considered

Qualitative review of thermoeconomic analyses in solar refrigeration systems applied to absorption chillers

The implementation of solar refrigeration in absorption chillers has been a topic widely researched in the scientific community in view of the search for compatibility of the thermal comfort standards required in the current century with the need to search for the consumption of sustainable energy sources in refrigeration equipment. Based on this scenario, this work aimed to conduct a qualitative literature review of thermoeconomic analyses in solar cooling systems applied to absorption chillers. As a result, a volume of research was obtained in three basic categories: energy and exergetic analyses in low capacity chillers, effect of the climate on the thermoeconomic performance of absorption systems by solar refrigeration and the implementation of cogeneration systems using solar energy as one of the sources.

Redesign of Trans-Semarang Bus Stop at Prof. Soedarto Segment Using an Accessibility Approach

Bus rapid transit, which was established in the city of Semarang in 2009, is expected to be a solution for the transportation needs of the people of the city of Semarang. With good service and economical prices, bus rapid transit is quite a favorite form of transportation for the citizens of Semarang. However, the current design of the Trans-Semarang bus stop is still far from easy for its users to access. The need for public services in the form of easy accessibility of users, both disabled and elderly. There needs to be a review from the Semarang City government, regarding the fulfillment of bus shelter facilities and designs that are still less than standard. This study uses a descriptive method using qualitative techniques. The research subjects were bus stops and users of the Trans-Semarang bus stop. Data collection techniques used are observation and documentation. The results of the research obtained on the design of the Trans-Semarang bus stop indicate that there are several shortcomings in the design of the Trans-Semarang bus stop along the Prof. Soedarto. To achieve the standard of comfort in terms of accessibility, it is necessary to redesign the bus stop design following the standards of building design regulations. Some of these shortcomings have been improved by redesigning the Trans Semarang bus stop with an accessibility approach. In addition, it is necessary to add several facilities that are not yet available so that the function of the Trans-Semarang bus stop can be used optimally and sustainably by the residents of Semarang.

Examining thermal comfort levels and ASHRAE Standard-55 applicability: A case study of free-running classrooms in Abuja, Nigeria

Most thermal comfort research has traditionally focused on office and commercial buildings as opposed to educational facilities. Due to the high population density in schools and the undesirable impact an unsuitable thermal setting can have on performance, teaching and learning, providing thermal comfort in school facilities is crucial. Considering the above information, this study aims to collect empirical data from secondary schools in Abuja’s hot and dry climate to evaluate thermal comfort settings for students in naturally ventilated classrooms and the applicability of ASHRAE Standard-55 in the area. To achieve this, field investigations were conducted in free-running classrooms from four secondary schools. The study involved 1448 students drawn from 41 classrooms. Data collection involved measuring classroom thermal comfort variables and respondent survey, simultaneously performed while students were learning in the classroom. Findings revealed none of the studied classrooms’ thermal conditions met the ASHRAE Standard-55 comfort range. However, 44% of students felt comfortable. The study indicated a regression-neutral temperature of 28.8°C and a ‘comfort temperature’ range of 26 to 31°C. The findings of this research could form the foundation data for a local thermal comfort standard. However, the prior thermal experiences of respondents were not investigated in this study.

Exploring Energy Retrofitting Strategies and Their Effect on Comfort in a Vernacular Building in a Dry Mediterranean Climate

This research explores the energy behaviour of a traditional house on the Mediterranean coast of south-eastern Spain. The objective of the work is to determine the optimal passive strategies for rehabilitating a traditional house, improving its energy savings and comfort, considering the characteristics of the warm semi-arid Mediterranean climate. The main novelty of this article is that it demonstrates that the limits imposed by current regulations, based on globalised climate strategy approaches, undermine the energy efficiency capacity that passive solutions in vernacular architecture already employed. The methodology used consists of a systematised multi-objective study of various energy rehabilitation strategies. Four strategies were studied: raising the thermal insulation of enclosures, improving thermal insulation and solar control glazing with movable shading devices, increasing the size of windows and introducing the use of natural ventilation enhanced by ceiling fans. The results show that simultaneous improvement of these parameters reduces cooling and heating requirements by up to 87%, reducing the energy consumption of air conditioning systems. Indoor temperatures are also maintained within the comfort limits set by regulations for 91% of hours per year without the need for air conditioning systems. This results in a passive energy-efficient and comfortable house almost all year round. This work offers an alternative solution to the comfort standards of current Spanish regulations and demonstrates the need to adapt Fanger’s analytical method for comfort estimation. The research concludes that the comfort criteria of current energy regulations should be modified to better adapt the design criteria to the dry Mediterranean climate.

Analisis Kepuasan Pengguna Transportasi Umum Ojek Online (Gojek) Melalui Instrumen Layanan

In Indonesia, online motorcycle taxis are the largest public transportation with a very large number of partners and fleets, covering all parts of Indonesia. As a profit-oriented mode of public transportation, paying attention to customer satisfaction is a necessity. One of the efforts that can be done is to provide quality services. In fact, this study aims to find out how online transportation users respond by looking at the service elements provided by service providers. Scientific studies are used as a logical way to prove reliable research results, and in this study using quantitative methods and statistical analysis of linear regression. The subjects of this study were users of the online ojek public transportation mode in the student MPLM UNJ 2022,Jakarta. The results of the study provide an overview, in general, respondents are satisfied with the presence of nline motorcycle taxis. This is very helpful and facilitates user activities. However, there are still things that need to be improved, such as comfort and safety standards. Statistically, service has a significant effect on online motorcycle taxi user satisfaction.

Subaltern housing policies: Accommodating migrant workers in wealthy Geneva.

In the wealthy and orderly city of Geneva, Switzerland, accommodation centres built in haste between the 1950s and the 1980s to house seasonal guestworkers from southern Europe are still standing and still inhabited. Today's residents are precarious workers, undocumented or with temporary permits as well as asylum seekers. While the seasonal status disappeared in the early 2000s, the demand for low-skilled, flexible labour did not. Analysing the historical trajectories of specific buildings helps us to answer the question of who replaced the seasonal workers, not only in the labour and the housing markets, but also in the symbolic spectrum of legitimacy. This article introduces the notion of 'Subaltern Housing Policies' to account for the public action that leads to the production and subsequent use of forms of housing characterised by standards of comfort and security far below those of the rental and social housing stock, but considered 'good enough' for their occupants. We argue that 'subaltern' relates not only to housing conditions, but also to the policies themselves, and last but not least to the people who are subjected to them. This notion allows us to trace a link between the production of substandard forms of housing and the production of categories of people who are kept on the margins of full citizenship.

Adaptive thermal comfort of residential buildings in the composite climatic region of India: a field study

ABSTRACT This paper presents the results of an adaptive thermal comfort field study conducted in the naturally ventilated residential buildings in the composite climate type of India over three main seasons i.e. monsoon, winter, and summer using ASHRAE’s class II field measurements protocols. 768 measurements were collated wherein subjective thermal comfort sensation, preference, and acceptance for indoor environment variables were thoroughly explored along with the adaptive actions of the users for four different times during a day. Correlation analysis helped decipher the relationship between subjective votes and thermal comfort evaluation parameters. Thermal environment acceptance during monsoon season and morning time was highest however the same was found lower during summers and afternoons. The middle age group had the lowest acceptance and well-acclimatized non-native participants had a good thermal acceptance. Education also affects thermal acceptance and it decreases with increasing education level. The comfort temperature and adaptive comfort equation were also studied and results were compared with national and international thermal comfort standards. This study predicted a wider thermal comfort range of 12.23–34.45°C and indicated revising TSI, the first thermal comfort index for Indian Subjects.