Environmental Quality Performance Research Articles

Achieving net-zero emission target in Africa: Are sustainable energy innovations and financialization crucial for environmental sustainability of sub-Saharan African state?

Following the rising importance of energy transition in the environmental sustainability discussion, it is imperative to understand the roles of sustainable energy innovations and financialization to reach informed inferences for policy formulation. We examined the environmental quality performance in Sub-Sahara Africa using the case of the resource-rich Ghanaian state vis-à-vis the possible moderating influence of green innovations and financial development. The empirical analysis encompassed various estimation issues, including structural breaks, heteroscedasticity, and normality in data structure. We simulated with the dynamic autoregressive-distributed lag technique and confirmed that financialization, resource rents, and economic growth are significant positive determinants of pollutant emissions. However, green innovations decrease the rate of pollution in the nation. Moreover, the interaction between green innovations and financial development improves ecological quality, while that between natural resources and financial development spurs pollution in the ecosystem. Furthermore, causal connections in the series indicated unidirectional causalities from green innovations, financialization, natural resource rents, and economic growth to pollutant emissions. However, the interactive terms between green innovations and financial development and between natural resource rents and financial development are bi-directionally related to ecological pollution. Hence, the study essentially suggests that the net-zero emission agenda of the Paris Accord is achievable from higher investments in green innovations while harnessing the benefits of international financial flows to boost the sustainability capacity of the Sub-Saharan Ghanian economy.

Environmental Performance of the Stormpav Permeable Pavement Using the Stormwater Management Model (SWMM)

Urban stormwater runoff is contaminated with a variety of pollutants, including total suspended solids (TSS) and total phosphorus (TP), as a result of non-source pollution from transportation, residences, and businesses, as well as sediment from human activities and construction sites. These pollutants are expected to degrade the water quality in local rivers and streams, impairing the quality of marine life and contaminating drinking water supplies. This study evaluates the environmental performance of a permeable pavement system in an urban catchment using the stormwater management model (SWMM). Two pavement systems with different hydraulic designs were compared to reduce runoff, increment of groundwater storage and the environmental parameters assessments on total suspended solids (TSS) and Total Phosphorus (TP). The first system comprises a StormPav, which is the UNIMAS innovated green pavement with subsurface hollow cylindrical micro-detention pond storage of about 70% void content. The second system consists of porous concrete (PC) pavement assembled in a layered of coarse and fine particles to ensure water can infiltrate through, with about 40% void content. The environmental impact assessment was applied at Padungan Commercial Centre in the Kuching City of Malaysia. The case study simulated in low impact development (LID) sub-catchment in SWMM to obtain the runoff, infiltration and environmental quality performance. In the assessment, it was found that, for both pavement systems, higher stormsat shorter duration resulted in higher reduction efficiency. The StormPav is more effective in reducing runoff, while presenting a lower value for environmental assessments in removing TSS and TP compared to PC.

Adaptive thermal comfort in the offices of three climates of North-East India

Buildings not only provide shelter to the occupants but also security, safety and comfort, as well as signifying economic and socio-cultural status. The high energy intensity of buildings has become a matter of concern worldwide in the context of climate change and global warming. Adaptive comfort principles and guidelines afford greater design opportunities for reduced energy intensity without compromising occupant thermal comfort and indoor environmental quality performance. However, thermal adaptation opportunities of office occupants in the North-Eastern part of India are rarely addressed by previous thermal comfort studies conducted in the Indian subcontinent. A yearlong questionnaire-based adaptive thermal comfort study with concurrent indoor environmental measurements was conducted in naturally ventilated office buildings located in three locations, i.e., Tezpur, Imphal and Shillong, representing the climatic zones of North-East India. A total of 2326 valid questionnaire responses were collected. ASHRAE Class-II field study protocols, seven-point thermal sensation and five-point preference scales were used to collect objective and subjective comfort assessments. It was found that the clothing insulation (clo) levels worn by occupants varied non-linearly with indoor temperatures. The estimated preferred temperatures for building occupants in Tezpur, Imphal and Shillong were 24 °C, 23.5 °C and 22 °C, respectively. Probit analysis of thermal sensation data indicated that the indoor temperature stimulus associated with a shift of one thermal sensation unit differed between the warm and cool side of the 7-point thermal sensation scale. Increasing indoor air velocity up to 0.8m/s shifted the upper threshold of discomfort to 32 °C. It was also found that 80% of office occupants were comfortable within the temperature range of 25 °C–30 °C. The adaptive comfort model derived from the current database shows lower sensitivity of subjects to outdoor temperature changes compared to existing International standards like ASHRAE Standard 55 or EN16798. The present study demonstrates the potential for low-energy, naturally ventilated office design strategies in similar climatic conditions in North-East India and other parts of the world. Above all, it enriches the worldwide thermal comfort database.

The indoor environmental quality and energy savings potential of room ventilation units compared to exhaust-only ventilation systems in France

Humidity-controlled mechanical exhaust ventilation (RH-MEV) has been widely used in France for over 35 years, demonstrating high durability and robustness. This exhaust-only ventilation strategy is widely used as an energy-saving measure, replacing constant mechanical exhaust ventilation (Constant-MEV) systems in residential buildings. It demonstrates energy savings due to the restricted airflows, but as a downside, the building’s indoor air quality (IAQ) often deteriorates. Moreover, it is impossible to recover heat with exhaust-only ventilation systems, which means that energy consumption for space heating is still quite significant and cold supply air temperatures are frequently introduced to the heated spaces. Room ventilation units (RVUs) with heat recovery represent an alternative ventilation solution allowing simple installation through the façade and providing fresh outdoor air and exhaust ventilation to each room. This study investigates these units’ energy saving potential and indoor environmental quality performance as an alternative solution to centralized exhaust-only ventilation systems. The dynamic simulations were performed for a reference residential building under various French climatic conditions for a heating season. The three ventilation strategies investigated were Constant-MEV, RH-MEV and room-based ventilation with RVUs. The results demonstrated 61–85% savings in space heating demand with the RVUs, compared to Constant-MEV under all climatic conditions. Compared to RH-MEV, the RVUs saved 44–75% energy for space heating while the CO2 concentration and relative humidity levels were decreased due to RVUs’ constant air exchange rate. In all cases, RVUs provided considerably higher supply air temperatures due to the implemented heat recovery, which can potentially improve indoor thermal comfort.

An agile new product development-based sustainable supply chain framework to improve environmental quality performance: emerging economies perspective

PurposeSustainable supply chain management (SSCM) is a new subfield of supply chain management. The purpose of this research is to develop a framework for assessing the impact of agile new product development (ANPD) practices on the environmental SSCM performance.Design/methodology/approachThe ANPD practices and SSCM environmental performance metrics (SEPMs) are identified through the literature review. The shortlisted ANPD practices are categorized into five major criteria each with an own set of sub-criteria. A four-level conceptual framework is developed. The weights of these ANPD practices are computed using the Pythagorean fuzzy Analytical Hierarchy Process (PFAHP), and the SEPMs are ranked using the Pythagorean fuzzy Combined Compromise Solution (PFCoCoSo).FindingsThe results show that the major criterion “Innovation Aspects” is the most important with a weightage of 0.2368, followed by “Policy Aspects” having 0.2228, “Technology Aspects” with 0.1959, “Organisation Aspects” having 0.1786 and “Executive Aspects” with 0.1658 weightage. The SEPMs “Frequency of NPD” is ranked first with an assessment value (Ki) of 2.5569, followed by “Lead time reduction” and “Number of design iterations” with Ki of 2.4482 and 2.3897, respectively. The research findings show that the ANPD practices like customer need assessment, availability of multidisciplinary team and Industry 4.0 technology usage contribute more to achieving environmental SSCM.Practical implicationsManagers can enhance environmental SSCM performance by adopting the ANPD practices and prioritizing SEPMs. Corporate effectiveness will be increased by the practices that promote SSCM and the use of technological innovations.Originality/valueThis study identified a unique set of 22 performance metrics that quantitatively measure NPD performance as well as environmental SSCM performance by adopting the 31 ANPD practices that were shortlisted. The proposed framework is a novel synthesis of literature from various disciplines such as new product development (NPD), environmental management, SSCM and performance evaluation.

Assessing measurement model of green cleaning components for green buildings

PurposeThis paper aims to assess a measurement model of green cleaning for green buildings in Malaysia. Being one of the contributors to the indoor environmental quality performance, green cleaning has become one of the significant aspects that need to be considered for the well-being and performance of a building, particularly in a green building's operations and maintenance performance. Green buildings without green cleaning practices would hinder the benefits that should be rendered economically, socially and environmentally. However, the absence of clear green cleaning components and requirements in Malaysia has become a motivation to undertake this research.Design/methodology/approachA questionnaire survey involving cleaning service providers and green building index (GBI) facilitators was carried out, and the data was then analyzed using partial least squares structural equation modeling. However, this paper will only be focusing on the measurement model assessment.FindingsMost of the green cleaning components and requirements are acceptable in the model except integrated pest management (in the cleaning procedure component) and hand soaps (in the product and materials component) due to lower factor loadings. Therefore, these two requirements were removed from the measurement model.Research limitations/implicationsDue to a paucity of professionals in the field of green cleaning, the researchers have selected GBI facilitators and cleaning service providers as respondents for this research. The researchers assumed that GBI facilitators are aware of acceptable products and materials for green buildings; meanwhile, cleaning service providers know what is the best cleaning technique and process that helps in achieving cost and resource efficiency. This research also assumed that the green cleaning components identified can be applied to any type of green building, regardless of the differences in needs in each type of building.Practical implicationsThis discovery will give the industry, particularly cleaning service providers and green building management teams, a first look at the green cleaning components and requirements.Originality/valueThis paper fulfills the need to study how green cleaning helps in achieving the benefits rendered by green buildings.

Exploring Links to Life in a Nigerian Urban Fringe

Finding what makes urban fringes meaningful for living has become a herculean challenge in the urban planning and design fields. Studies considering place-making endeavors to unveil meanings of urban fringes lay less emphasis on environmental quality performance. Many studies suggest that urban fringes have the capacity to absolve increasing rates of urbanization especially in developing countries to ensure urban sustainability ditto to the fact that urban fringes are sites experiencing and prone to continuous changes, exchanges, transformations and successions over time. Hence, these places need to be studied for an understanding of residents’ realities associated with settlement growth and development processes in a bid to explore and establish links between their place making conditions and performance criteria through participant observation and a theoretical framework. It is hoped that this study will be a step further to planning sustainable urban settlements and developments.

Modelling platform for schools (MPS): The development of an automated One-By-One framework for the generation of dynamic thermal simulation models of schools

The UK Government has recently committed to achieve net zero carbon status by year 2050. Schools are responsible for around 2% of the UK’s total energy consumption, and around 15% of the UK public sector’s carbon emissions. A detailed analysis of the English school building stock’s performance can help policymakers improve its energy efficiency and indoor environmental quality.Building stock modelling is a technique commonly used to quantify current and future energy demand or indoor environmental quality performance of large numbers of buildings at the neighbourhood, city, regional or national level. ‘Building-by-building’ stock modelling is a modelling technique whereby individual buildings within the stock are modelled and simulated, and performance results are aggregated and analysed at stock level.This paper presents the development of the Modelling Platform for Schools (MPS) – an automated generation of one-by-one thermal models of schools in England through the analysis and integration of a range of data (geometry, size, number of buildings within a school premises etc.) from multiple databases and tools (Edubase/Get Information About Schools, Property Data Survey Programme, Ordanance Survey and others). The study then presents an initial assessment and evaluation of the modelling procedure of the proposed platform.The model evaluation has shown that out of 15,245 schools for which sufficient data were available, nearly 50% can be modelled in an automated manner having a high level of confidence of similarity with the actual buildings. Visual comparison between automatically-generated models and actual buildings has shown that around 70% of the models were, indeed, geometrically accurate.

Developing a Data-driven school building stock energy and indoor environmental quality modelling method

The school building sector has a pivotal role to play in the transition to a low carbon UK economy. School buildings are responsible for 15% of the country’s public sector carbon emissions, with space heating currently making up the largest proportion of energy use and associated costs in schools. Children spend a large part of their waking life in school buildings. There is substantial evidence that poor indoor air quality and thermal discomfort can have detrimental impacts on the performance, wellbeing and health of schoolchildren and school staff. Maintaining high indoor environmental quality whilst reducing energy demand and carbon emissions in schools is challenging due to the unique operational characteristics of school environments, e.g. high and intermittent occupancy densities or changes in occupancy patterns throughout the year. Furthermore, existing data show that 81% of the school building stock in England was constructed before 1976. Challenges facing the ageing school building stock may be exacerbated in the context of ongoing and future climate change.In recent decades, building stock modelling has been widely used to quantify and evaluate the current and future energy and indoor environmental quality performance of large numbers of buildings at the neighbourhood, city, regional or national level. Building stock models commonly use building archetypes, which aim to represent the diversity of building stocks through frequently occurring building typologies.The aim of this paper is to introduce the Data dRiven Engine for Archetype Models of Schools (DREAMS), a novel, data-driven, archetype-based school building stock modelling framework. DREAMS enables the detailed representation of the school building stock in England through the statistical analysis of two large scale and highly detailed databases provided by the UK Government: (i) the Property Data Survey Programme (PDSP) from the Department for Education (DfE), and (ii) Display Energy Certificates (DEC). In this paper, the development of 168 building archetypes representing 9,551 primary schools in England is presented. The energy consumption of the English primary school building stock was modelled for a typical year under the current climate using the widely tested and applied building performance software EnergyPlus. For the purposes of modelling validation, the DREAMS space heating demand predictions were compared against average measured energy consumption of the schools that were represented by each archetype. It was demonstrated that the simulated fossil-thermal energy consumption of a typical primary school in England was only 7% higher than measured energy consumption (139 kWh/m2/y simulated, compared to 130 kWh/m2/y measured). The building stock model performs better at predicting the energy performance of naturally ventilated buildings, which constitute 97% of the stock, than that of mechanically ventilated ones. The framework has also shown capabilities in predicting energy consumption on a more localised scale. The London primary school building stock was examined as a case study.School building stock modelling frameworks such as DREAMS can be powerful tools that aid decision-makers to quantify and evaluate the impact of a wide range of building stock-level policies, energy efficiency interventions and climate change scenarios on school energy and indoor environmental performance.

Application of smart readiness indicator for Mediterranean buildings in retrofitting actions

Recent years have seen an increasing need to invest in smart, energy-efficient technologies in buildings to improve health and convenience for occupants and to reduce energy consumption and carbon emission impacts. Digitalization and developments in the information and communication technology sector play a critical role in improving the efficiency of the European energy market and remaining in the current progress of sustainable and renewable energy systems. Therefore, the European Union Member States are required to establish an optional common scheme for defining and calculating a descriptor, called a smart readiness indicator to assess the capabilities of buildings to adapt their operation to the needs of the occupants and the electricity grid and to achieve more efficient operation.This indicator is calculated using a methodology proposed and developed by the European Commission Directorate-General for Energy which depends to a great extent on various factors such as building type and climate conditions. The effectiveness of these parameters on the Smart Readiness Indicator is reflected by the weighting coefficients which need to be initially defined by the legislator. Therefore, the main step to assess the viability of this methodology, is to test it in different situations, i.e., various building types, climate conditions, etc. To this end, the proposed methodology is applied in two service buildings with different levels of energy and indoor environment quality performance located in an area with a Mediterranean climate. The possible effects of smart services and retrofit actions on indoor environment quality and energy performance in the buildings were assessed through energy simulation for two separate rooms in the buildings, a monitoring campaign and a survey to assess the occupants’ subjective opinion about the indoor environmental quality using the questionnaire proposed by the Centre for the Built Environment of the University of California.The results imply that, although the proposed methodology was able to recognise the overall characteristics of the sample buildings, some amendments are still required to capture the specific features of non-residential Mediterranean climate buildings. More specifically, the defined weighting factors fail to reflect the actual energy performance of the service buildings and need to be revised. Moreover, the current retrofitting actions which were implemented to improve energy efficiency and thermal comfort in the building were not as effective as expected in enhancing the SRI value.

Monitoring the performance of a Passivhaus care home: Lessons for user-centric design

The paper presents the results of monitoring a Passivhaus care home regarding the effect of design intentions, occupancy practices and user preferences, on building energy and indoor environmental quality performance through a mixed methods approach. The results of the thermal comfort assessment showed that the staff is uncomfortable, while the residents are comfortable. Warm temperatures are preferred by the residents. The staff understands the needs of the residents and acknowledge the fact that their discomfort assures the comfort of the residents. Energy usage is higher than expected. None of the daily routines required in a care home were considered in the energy calculations. The calculations were made by a team of designers, who did not know well the activities carried out in the care home. As a result, the expected performance of the building was unrealistic in terms of energy use. The results point at the importance of taking into account the user during the design process: even though the actual needs and preferences of the occupants were not considered in the energy calculations, they were considered in the design of the building's installations. This allowed the staff to air the rooms daily without compromising the comfort of the residents.

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

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.

Indoor Environmental Quality performance of mixed-mode ventilated shopping malls in hot-humid climatic region

Studies have revealed important roles quality indoor environment plays on human health and productivity; consequently, its influence on certain shopping behavior has also been well spelt out. In other to keep up with the demand for quality indoor environment, new trend has been evolving in the design of Malaysian shopping malls. From fully air-conditioned to newly designed ones that integrate passive ventilation strategies; and as such operating under mixed-mode ventilation system. These passive ventilation strategies are implemented to reduce energy consumption and also to improve the indoor environment within the mall’s indoor space. However, the potentials of these designs in terms of their indoor environmental quality (IEQ) performance have not been studied nor have their advantages been revealed. In this study, occupants’ thermal perception and IEQ performance was investigated in two mixed-mode ventilated malls selected based on their design concept (‘open’ and ‘enclosed’). Both subjective and objective measurements were carried out in accordance with the ASHRAE performance measurement protocol for commercial buildings. Five IEQ factors (indoor air temperature, operative temperature, relative humidity, air speed, and carbon dioxide concentration level) were evaluated in the two malls. The results revealed that both malls fell below the ASHRAE comfort requirement but majority of the occupants still found the indoor thermal performance acceptable despite the high indoor air temperature recorded. For both malls, high air speed and low humidity level were recorded. However, higher air movement was still preferred by the occupants while the recorded mean carbon dioxide (CO2) concentration was within the recommended level. The ‘open’ concept mixed-mode ventilated mall proved superior compared to the ‘enclosed’ concept by providing a more thermally tolerance indoor environment for its occupants. Generally, results from this study contribute to the knowledge on the advantages of adopting sustainable designs in commercial buildings for improving the indoor environment as well as the health and general well-being of the occupants. The study will open more opportunities for future IEQ studies to be carried out in hot-humid climatic regions.

Indoor environmental quality performance and occupants’ satisfaction [IEQPOS] as assessment criteria for green healthcare building rating

A building as shelter is designed to provide an indoor environmental quality (IEQ) that is comfortable and appealing to its users. Having the understanding of the relationship between IEQ performance in buildings and the overall satisfaction derivable from the environment by the building occupants are necessary variables that will enhance the formulation of the requirements for architectural and building systems design and control. This study is aimed at developing a conceptual framework model for evaluating the performance of IEQ and occupants' satisfaction in hospital ward buildings. This conceptual framework is based on hypothesised model constructs, using Confirmatory Factor Analysis (CFA) and Structural Regression Models (SRM). The data were analysed, using Structural Equation Modelling (SEM). The analysis of the different specified model constructs in the framework resulted in an evaluation model for IEQ performance (IEQPM) and occupants' satisfaction (IEQPOS) in hospital ward buildings. The IEQPM model indicated that thermal quality, acoustic quality, visual quality, and indoor air quality (IAQ) are significant determinants of IEQ performance indirectly measured through the interrelationship among ten different indoor environment indicators. However, the level of importance of the four parameters of the IEQ performance differed, having different weighting factors of 0.61, 0.53, 0.40, and 0.47. The significant relationship between IEQ performance and occupants' satisfaction as established by the IEQPOS model resulted into a single index score value called ‘Comprehensive Occupant Satisfaction’ Index (COSI) which can be used for the assessment of occupancy comfort survey aspect of IEQ criteria in green building rating system.

Indexing the Environmental Quality Performance Based on A Fuzzy Inference Approach

Environmental performance strongly deals with the quality of human life. In Indonesia, this performance is quantified through Environmental Quality Index (EQI) which consists of three indicators, i.e. river quality index, air quality index, and coverage of land cover. The current of this instrument data processing was done by averaging and weighting each index to represent the EQI at the provincial level. However, we found EQI interpretations that may contain some uncertainties and have a range of circumstances possibly less appropriate if processed under a common statistical approach. In this research, we aim to manage the indicators of EQI with a more intuitive computation technique and make some inferences related to the environmental performance in 33 provinces in Indonesia. Research was conducted in three stages of Mamdani Fuzzy Inference System (MAFIS), i.e. fuzzification, data inference, and defuzzification. Data input consists of 10 environmental parameters and the output is an index of Environmental Quality Performance (EQP). Research was applied to the environmental condition data set in 2015 and quantified the results into the scale of 0 to 100, i.e. 10 provinces at good performance with the EQP above 80 dominated by provinces in eastern part of Indonesia, 22 provinces with the EQP between 80 to 50, and one province in Java Island with the EQP below 20. This research shows that environmental quality performance can be quantified without eliminating the natures of the data set and simultaneously is able to show the environment behavior along with its spatial pattern distribution.

THE INDOOR ENVIRONMENTAL QUALITY PERFORMANCE OF GREEN LOW-INCOME SINGLE-FAMILY HOUSING

There is little empirical evidence in the literature about the indoor environmental quality performance of residential buildings in general and of social housing in particular. To address this problem, this study used a mixed-method approach to evaluate the indoor environmental quality performance of 17 green low-income single attached family houses in Brandon, Manitoba, Canada. Questionnaires were administered to occupants to assess their snapshot and long-term satisfaction with the indoor environment. In addition, snapshot measurements were carried out to evaluate the indoor environmental quality factors of thermal comfort, indoor air quality, lighting and acoustics. Occupants' snapshot satisfaction was categorized into two groups (i.e. satisfied/comfortable or dissatisfied/uncomfortable) and compared with snapshot measurements. The results showed the measured IEQ parameters were well below recommended threshold levels. Further, occupants with higher snapshot satisfaction were generally exposed to relatively lower levels of indoor pollutants. A statistically significant difference was found in PM10 level only between the snapshot satisfied and snapshot dissatisfied groups of occupants. Apparent sound transmission classes were below the standard reference value of 50, suggesting potential problems in noise attenuation within different spaces in each apartment and between apartments. The findings of this study could help governments implement green shadowing for public-housing and also renovate existing houses using the same principles.

Indoor environmental quality (IEQ) analysis of a low energy wind catcher with horizontally-arranged heat transfer devices

Windcatchers are natural ventilation systems based on the design of traditional architecture, intended to provide ventilation by manipulating pressure differentials around buildings induced by wind movement and temperature difference. Though the movement of air caused by the wind catcher will lead to a cooling sensation for occupants, the high air temperature in hot climates will result in little cooling or thermal discomfort to occupants. In order to improve the cooling performance by wind catchers, heat transfer devices were incorporated into the design. This work will investigate the indoor environment quality performance of a roof-mounted cooling windcatcher integrated with horizontally-arranged heat transfer devices (HHTD) using Computational Fluid Dynamics (CFD) and field test analysis. The windcatcher model was incorporated to a 5mx5mx3m test room model. The study employed the CFD code FLUENT with the standard k- model to conduct the steady-state RANS simulation. For the indoor CO2 concentration analysis, a simplified exhalation model was used and the room was filled with 12 occupants. The CO2 concentration analysis showed that the system was capable of delivering fresh air inside the space and lowering the CO2 levels. Thermal comfort analysis using the Predicted Mean Vote (PMV) was conducted whereby the measurements ranged from slightly-cool (-0.96) to slightly warm range (0.36 to 0.60). Field test measurements were carried out in the Ras-Al-Khaimah (RAK), UAE during the month of September. Numerical model was validated using experimental data and good agreement was observed between both methods of analysis.

An integrated approach on energy consumption and indoor environmental quality performance in six Portuguese secondary schools

A major rehabilitation programme of secondary school buildings has been carried out in the last few years in Portugal. With the introduction of HVAC systems in buildings that were previously naturally ventilated, an increase on energy consumption has been verified. During the first occupancy periods of new and refurbished buildings, energy and indoor climate quality audits are important strategies to improve the buildings’ energy use. In this context, this paper aims at showing the relations between the energy consumption and indoor environment quality (IEQ) parameters, obtained from the energy and IEQ audit in six representative modernised secondary schools – part of a larger R&D project untitled 3Es – geographically and climatically distributed in Portugal mainland.The monitoring period during the mid-season 2013 varied between schools, between two and three weeks. Air exchange rates, more specifically infiltration rates, were quantified aiming at determining the current airtightness condition of the refurbished schools. A subjective IEQ assessment was also performed, focusing on occupants' feedback, providing insight on the potential linkages between energy use and occupants’ comfort.A reflection on the energy consumption indicators and the indoor conditions obtained in the classrooms was proposed, and some suggestions were anticipated.

바닥공조 시스템이 적용된 사무공간의 거주후 성능평가

In this study, an underfloor air distribution(UFAD) system installed on the S. office building was evaluated for its indoor environmental quality performance. Field measurement and survey were conducted for the overall POE(Post Occupied Evaluation). PMV(including temperature, humidity, air velocity and globe temperature) and several environmental components were measured while thermal comfort, thermal sensation, acoustical environment and others. were investigated through survey. Except for the direct upper part of the air supply diffuser on the floor, the indoor velocity was less than 0.25m/s, which has been suggested by ASHRAES tandard 55 as the limit for thermal comfort. MRT of the perimeter zone of the room showed a higher value than that in the interior because of the introduced solar radiation through the building envelope. PMV was generally maintained in the range of thermal comfort (from -0.5 to +0.5), though it weighted to the warm side. It was reported to have 61% positive response on thermal comfort and 55% on neutral thermal sensation. The results of each survey item showed some gender-based differences. Specifically, female respondents had higher degree of dissatisfaction with indoor air cleanness and acoustical privacy. The working surface showed more than 400 lux and the equivalent noise level showed less than 50 dB(A). In conclusion, the results of the measurement and survey showed good agreement. Indoor environmental quality of the subject office room where the UFAD system was installed showed an overall excellent performance.

The Air Distribution Index as an Indicator for Energy Consumption and Performance of Ventilation Systems

This paper deals with the energy consumption and the evaluation of the performance of air supply systems for a ventilated room involving high- and low-level supplies. The energy performance assessment is based on the airflow rate, which is related to the fan power consumption by achieving the same environmental quality performance for each case. Four different ventilation systems are considered: wall displacement ventilation, confluent jets ventilation, impinging jet ventilation and a high level mixing ventilation system. The ventilation performance of these systems will be examined by means of achieving the same Air Distribution Index (ADI) for different cases.The widely used high-level supplies require much more fan power than those for low-level supplies for achieving the same value of ADI. In addition, the supply velocity, hence the supply dynamic pressure, for a high-level supply is much larger than for low-level supplies. This further increases the power consumption for high-level supply systems.The paper considers these factors and attempts to provide some guidelines on the difference in the energy consumption associated with high and low level air supply systems. This will be useful information for designers and to the authors' knowledge there is a lack of information available in the literature on this area of room air distribution.The energy performance of the above-mentioned ventilation systems has been evaluated on the basis of the fan power consumed which is related to the airflow rate required to provide equivalent indoor environment. The Air Distribution Index (ADI) is used to evaluate the indoor environment produced in the room by the ventilation strategy being used. The results reveal that mixing ventilation requires the highest fan power and the confluent jets ventilation needs the lowest fan power in order to achieve nearly the same value of ADI.