Installation Considerations Research Articles

Advanced energy management scheme for fuel cell-based microgrid using self–regulated controller and switched capacitor inverter

Clean energy production is now the main challenge for sustainable future which can be addressed by introducing renewable energy sources. Fuel cells are critical in providing sustainable energy solutions by enabling efficient energy conversion in microgrids. To enhance the performance of fuel cell-based microgrids, advanced controllers and inverters are necessary to manage power quality and stability. One of the key benefits of this fuel cell is the separation of energy conversion and management, which allows independent optimization for each function of microgrid's performance, cost, or other installation considerations. The ability to individually control of each component of a microgrid can significantly impact various applications positively. Beyond their technological and economic advantages, fuel cells are highly sensitivity to microgrid's characteristics such as current quality and harmonics which creates difficulties for their design and management. Therefore, the entire microgrid must be managed by an effective energy management strategy and integration of advanced inverter topologies. This study aims to improve fuel cell efficiency and power quality within the microgrid through an advanced energy management (AEM) strategy. The proposed AEM structure is developed focusing on two key components: a self-regulated controller (SRC) and a switched capacitor multilevel inverter (SCMLI). These elements work together to mitigate the disturbances and enhance the power quality of the system. The methodology includes simulation and hardware-in-the-loop (HIL) testing under non-linear load conditions. Initial grid-side current total harmonic distortion (THD) of 28.38% was reduced to 2.19% through the proposed system. An impact analysis is also presented to demonstrates that reducing current harmonics and voltage imbalance have improved the efficiency of fuel cell to 50.18% and fuel utilization to 98.05%. The findings show that the proposed scheme significantly reduces current harmonics and improves the overall performance benchmark of the microgrid and fuel cell.

WATERHYPERNET: a prototype network of automated in situ measurements of hyperspectral water reflectance for satellite validation and water quality monitoring

This paper describes a prototype network of automated in situ measurements of hyperspectral water reflectance suitable for satellite validation and water quality monitoring. Radiometric validation of satellite-derived water reflectance is essential to ensure that only reliable data, e.g., for estimating water quality parameters such as chlorophyll a concentration, reach end-users. Analysis of the differences between satellite and in situ water reflectance measurements, particularly unmasked outliers, can provide recommendations on where satellite data processing algorithms need to be improved. In a massively multi-mission context, including Newspace constellations, hyperspectral missions and missions with broad spectral bands not designed for “water colour”, the advantage of hyperspectral over multispectral in situ measurements is clear. Two hyperspectral measurement systems, PANTHYR (based on the mature TRIOS/RAMSES radiometer) and HYPSTAR® (a newly designed radiometer), have been integrated here in the WATERHYPERNET network with SI-traceable calibration and characterisation. The systems have common data acquisition protocol, data processing and quality control. The choice of validation site and viewing geometry and installation considerations are described in detail. Three demonstration cases are described: 1. PANTHYR data from two sites are used to validate Sentinel-2/MSI (A&B); 2. HYPSTAR® data at six sites are used to validate Sentinel-3/OLCI (A&B); 3. PANTHYR and HYPSTAR® data in Belgian North Sea waters are used to monitor phytoplankton parameters, including Phaeocystis globosa, over two 5 month periods. Conclusion are drawn regarding the quality of Sentinel-2/MSI and Sentinel-3/OLCI data, including indications where improvements could be made. For example, a positive bias (mean difference) is found for ACOLITE_DSF processing of Sentinel-2 in clear waters (Acqua Alta) and clues are provided on how to improve this processing. The utility of these in situ measurements, even without accompanying hyperspectral satellite data, is demonstrated for phytoplankton monitoring. The future evolution of the WATERHYPERNET network is outlined, including geographical expansion, improvements to hardware reliability and to the measurement method (including uncertainty estimation) and plans for daily distribution of near real-time data.

Southern creative robotics – A collaborative framework to implement computational design, fabrication and robotics

Scientific knowledge, ideally neutral and impartial, is inevitably shaped by geographical, economic, and cultural contexts. This research contends that overcoming the constraints of human and economic scarcity, inertia, and limited funding access demands development of collaborative research networks. To this end, four university laboratories from Brazil and Chile - UFRJ, UBB, UTFSM and UAI - have united to advance robotics applied to architecture. The methodology begins with an analysis of Industry 4.0, Fab Lab implementations, and robotics in architecture in the region. They identify key research aspects by mapping each laboratory’s activities and technologies to pinpoint expertise and potential collaborative areas. The authors propose a summary table comparing the labs and a chronological overview to track regional robotics advancement. To raise awareness among peers, the initiative involves joint actions such as courses, workshops and technical visits. 1 Recognising the scarcity of robotic units and the inapplicability of procedures from wealthier contexts, the authors draw on their lab experience to propose guidelines for implementing robotics research units in academia within the region. This includes technological alternatives, installation considerations, and detailed configuration reviews. The deployment of additional robotic units is a means to foster collaboration and bolster the network. Anticipated outcomes encompass increased critical mass, collaborative research initiatives, faculty and student exchange across institutions, higher publication rates, knowledge acquisition, and improved access to global funding agencies. In summary, the Southern Creative Robotics network initiative aims to catalyse the creative integration of digital manufacturing and robotics technology within design in the Ibero-American context.

Lateral loading response of monopiles in sand considering installation effect

The effect of pile installation is a critical issue in the analysis and design of pile foundations but it is commonly ignored due to various numerical difficulties. In this paper, the installation process of an open-ended pipe pile into a sand deposit is simulated by using the zipper technique combined with the Arbitrary Lagrangian-Eulerian (ALE) method in the framework of three-dimensional (3D) finite element modeling. The subsequent lateral load response of the pile is also simulated and compared with that without consideration of the pile installation. The state dependent behavior of sand in associated with the pile installation and the subsequent lateral load is described using an advanced constitutive model. The study shows that for a relatively loose sand deposit, the sand surrounding the pile exhibits contraction and the disturbance zone takes the form of a trapezoid, whereas for a dense sand deposit, the sand near the pile will dilate and the disturbance zone takes the form of an inversed trapezoid. Furthermore, the deformation mode of the surrounding sand under the lateral load differs to some extent from that without consideration of the installation effect. Particularly, the location of the rotation point for the laterally loaded pile tends to move downwards when the pile installation process is considered.

SENSOR-ENHANCED CARE COORDINATION TO ADDRESS OLDER ADULT HEALTH: LESSONS FROM AN INTERDISCIPLINARY RESEARCH TEAM

Abstract Researchers at the University of Missouri have a history of developing and testing aging in place (AIP) care coordination models for clinical translation. Vital to this work are in-home, residentially installed sensors to detect early illness and functional decline over time. While much smart home research is focused on older adults living in continuing care retirement communities, our team developed a novel sensor-enhanced care coordination approach for community-dwelling and disabled older adults as part of two ongoing, federally funded projects. For this symposium, we will highlight the Age-friendly Sustainable Smart and Equitable Technologies for Aging in Place (ASSETs for AIP) demonstration program, funded by the Department of Health and Human Services. Our first presentation will overview our interdisciplinary approach to creating this novel care coordination model, with specifics about research team composition, population focus, and methods. Our second presentation will highlight recruitment strategies and share lessons learned from reaching and enrolling this population that often experience residential transitions. Our third presentation will overview the open-source smart home and consumer-grade technologies deployed in this work, and practical considerations for technology installation, support, and sustainability and clinical team training. Our symposium will close with a presentation of selected client case studies that illustrate how clinical care coordinators use sensor data to remotely monitor and empower older adults for behavior change via telehealth consultations. This symposium will help inform other care coordination research, particularly that which uses sensor technologies and telehealth to facilitate aging in place.

Numerical simulation of wind-induced load on evacuated tube solar water heaters

Solar Water Heater (SWH) has been used as a traditional device in many countries and regions for collecting solar energy. Unfortunately, there are many wind-induced accidents of SWHs, owing to insufficient consideration of wind-resistant design and installation. To better promote the safe use of SWHs, characteristics of wind load acting on them should be clarified thoroughly as far as possible. In this article, a systematic study is carried out by numerical simulation based on computational fluid dynamics (CFD) to analyze the effects of the tilt angle and density of evacuated tube collectors (ETC) as well as wind direction on the aerodynamic characteristics of SWH. Results show that the wind-resistance performance of SWH decreases significantly for wind flows blowing from 0° and 180° due to the influence of aerodynamic characteristics of its main components. When the ETC is located upstream of the water tank, the arrangement form of the tubes will have an impact on the aerodynamic characteristics of the SHW. A lower porosity of ETC can increase wind load on the weak region of water tank and the windward face of vertical supports, it can also increase the bending moment of inclined supports significantly. By contrast, lower tilt angles of ETC are more beneficial to the wind resistance of SHW, although they can result in an increase of the local wind suction on water tank.

How a Household Survived a Natural Hazard-Triggered Blackout with Photovoltaic and Battery Energy System: A Report of 2018 Hokkaido Eastern Iburi Earthquake in Japan

Energy-generating and storage systems, such as photovoltaic (PV) panels and energy storage batteries in homes, are becoming increasingly popular in the context of decarbonization. The systems are also expected to increase household resilience to natural hazard-triggered blackouts. However, how these systems contribute to the use of electrical appliances in households in actual cases is not sufficiently known. Therefore, this report aims to describe the activities that a household with an energy-generating and storage system could undertake during a natural hazard-triggered blackout. We focused on the blackout triggered by the 2018 Hokkaido Eastern Iburi Earthquake (approximately 2.95 million households lost power) and conducted an interview with a household living in a detached all-electric house with a PV and battery system. The results showed that the household lived without inconveniences during the blackout due to the power supply from the installed system, despite the weather. They charged cell phones and used a television, refrigerator, microwave oven, cooking heater, and bath. Moreover, the household’s electricity was also supplied to other households. These results clarified the actual benefit of enhancing household and community resilience of the systems. The results will aid household decision-making for the installation and governmental consideration of subsidies.

Optimal Sizing of Grid-Scaled Battery with Consideration of Battery Installation and System Power-Generation Costs

Variable renewable energy (VRE) generation changes the shape of residual demand curves, contributing to the high operating costs of conventional generators. Moreover, the variable characteristics of VRE cause a mismatch between electricity demand and power generation, resulting in a greater expected energy not supplied (EENS) value. EENS involves an expected outage cost, which is one of the important components of power-generation costs. A utility-scale battery energy storage system (BESS) is popularly used to provide ancillary services to mitigate the VRE impact. The general BESS ancillary-service applications are as a spinning reserve, for regulation, and for ramping. A method to determine optimal sizing and the optimal daily-operation schedule of a grid-scale BESS (to compensate for the negative impacts of VRE in terms of operating costs, power-generation-reliability constraints, avoided expected-outage costs, and the installation cost of the BESS) is proposed in this paper. Moreover, the optimal BESS application at a specific time during the day can be selected. The method is based on a multiple-BESS-applications unit-commitment problem (MB-UC), which is solved by mixed-integer programming (MIP). The results show a different period for a BESS to operate at its best value in each application, and more benefits are found when operating the BESS in multiple applications.

Portable Ultraviolet-C Chambers for Inactivation of SARS-CoV-2.

The goal of this project was to create and optimize the performance of portable chambers for reliable ultraviolet (UV) disinfection of personal protective equipment (PPE) and enable its safe reuse. During unforeseen times of high demand for PPE, such as during the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), single-use PPE supply can be quickly depleted. UV radiation has been shown to disinfect materials with high efficacy. This paper reports the design and construction of two 280 nm ultraviolet-C (UV-C) disinfection chambers in the form of portable chambers with 46 cm × 46 cm × 46 cm interior dimensions, one using light-emitting diodes and the other using mercury vapor lamps. This paper summarizes and presents a review of SARS-CoV-2 UV deactivation research during 2020 to 2021. Additionally, this paper discusses efforts to increase the uniformity and overall intensity of the UV-C radiation within the chambers through the installation of a UV-reflective, porous polytetrafluoroethylene (PTFE) material. A calculator prototype was additionally designed to calculate the reduction of SARS-CoV-2 as a result of UV-C disinfection, and the prototype code is presented. The paper describes the selection of UV-C radiation sources for the chambers and the chambers' mechanical and electrical design, PTFE installation, testing, and safety considerations.

Virtual fencing as a wildlife-vehicle collision mitigation measure: technical function, wildlife response and considerations for installation in an urban environment

ABSTRACT Virtual wildlife fencing presents as a cost-effective measure for roadkill mitigation, which aids in reducing fragmentation of wildlife populations by facilitating safer movement of wildlife across the landscape. In this study, we conducted an audit of a virtual fence installation in south-east Queensland, Australia. We assessed its reliability in flows of traffic and the effect that installation parameters and site conditions had on its effective operation in an urban setting. We made observations on the behavioural response of Eastern Grey Kangaroos Macropus giganteus to the acoustic signals produced by the fence. We found that the fencing activated consistently in response to headlights at dusk and dawn, and when traffic flows were dense, despite considerable variations in the range of installation parameters. However, we identified that the response of the virtual fence to headlights was affected by road curvature and we identified inconsistencies in the timing and pattern of activation in response to traffic. Behavioural observations showed a significant increase in kangaroo vigilance in response to the acoustic signal of the fence when resting or grazing, and kangaroos detected the acoustic signal up to 50 m away. While virtual fencing operates effectively and is a low-cost roadkill mitigation option that can be applied to the urban environment, more research is needed to better understand the effect of its acoustic and visual signals on wildlife behaviour and efficacy in busy urban environments.

An Angular Speed and Position FLL-Based Estimator Using Linear Hall-Effect Sensors

This paper proposes using a frequency-locked loop-based detector to estimate rotational speed and angle position for an electric machine rotor shaft. The measurement system consists of arrays of permanent magnets fixed to the rotor shaft together with linear Hall-effect sensors attached to a fixed frame. Parametric uncertainties on the sensor assembly lead to significantly noisy signals, exhibiting unbalance and harmonic distortion. To accurately estimate rotational speed and angle, it is proposed to use a frequency-locked loop scheme based on a fourth-order harmonic oscillator (FOHO) to allow the processing of the symmetric components, thus dealing with the unbalance. The scheme also includes an adaptive law to reconstruct the fundamental frequency. Moreover, a harmonic compensation mechanism comprising parallel FOHOs is included; each FOHO is tuned at the spectral component under concern for its cancellation. The proposed algorithm delivers a clean estimate of the positive sequence fundamental component despite the disturbances at the signals provided by the Hall-effect sensor, which is used to reconstruct the rotation angle. The described approach could enhance low-cost sensing solutions in applications where position feedback is mandatory and sensorless control is impossible, not requiring special installation considerations.

Implementing Technology-Based Visitor Counts in Parks: A Methodological Overview

Historically, documenting visitor counts in park, recreation, and tourism spaces has been fraught with challenges that often result in data with questionable reliability and validity. However, these counts are necessary for managers in that they inform budgets, staffing, and policy. The purpose of this methodological study is to detail the processes involved in implementing technology-based counting systems within parks with the goal of assisting managers who wish to modernize visitor counting procedures. The first step involves a detailed site analysis, with considerations specific to park boundaries, access to power sources, the availability of WiFi, and whether lighting is needed for the technology to function. Once the site analysis is completed, the technology options can be considered, with the understanding that the accuracy of the counts will be impacted by visitor flow, focal area of interest, the number of counters utilized, whether visitors must be carrying WiFi-enabled devices to be counted, data transmission options, and access to dynamic features such as those that eliminate double counts. A case study approach was used to demonstrate implementation procedures, focusing on site and technology selection, then moving on to installation considerations, data collection, validation, data analysis, and management implications. The Korean War Veterans Memorial (KOWA), a National Park Service holding located within the National Mall and Memorial Parks in Washington, DC, was selected as an optimal site based on semi-porous boundaries, consistent visitor flows, and ready access to power sources. After consideration of price, privacy, ease of installation, and ready access to data, 3D people counters were the chosen technology. The counters were installed in weatherproofed housings and mounted on lampposts that were situated at the two main entrance sites to the memorial. Analysis of twelve weeks of data indicated that the counting accuracy of the 3D counters was high, minimal modifications were needed, and visitor privacy was retained. A similar methodological approach can be applied by park managers within a wide variety of settings.

ІННОВАЦІЙНІ ЗВУКОВІ ТЕХНОЛОГІЇ ПРОСТОРОВОЇ ЗВУКОПЕРЕДАЧІ: РЕТРОСПЕКТИВА ЗВУКОВИХ ІНСТАЛЯЦІЙ

The purpose of the article is to determine the peculiarities of the development of the art of sound installation in the context of the concepts of acoustic space in the second half of the 20th – beginning of the 21st century. Research Methodology. The interdisciplinary methodology of critical spatial analysis and critical research in music has been applied to study the concepts of space and place, which became the basis for the practice of sound installation in the middle of the 20th century and the beginning of the 21st; systemic and evolutionary methods that have contributed to the consideration of the musical installation in the general philosophical and ontological plane in order to obtain the results useful in music and related sciences. Scientific Novelty. The peculiarities of the formation and development of the art of sound installation through the prism of the concepts of acoustic space of the second half of the 20th – beginning of the 21st century have been studied; for the first time in Ukrainian art studies, the essential foundations of sound installation are revealed in the context of the interpretation of the concept of a reflected sound object, alternative and extended concepts of space, in particular, the concept of space as a social production; the concepts of “spatial sound”, “spatial music” and “musical installation” have been considered; the means of sound ontology have been analysed in direct connection with the ontologies of space and place. Conclusions. The study has revealed that the concepts of acoustic space of the middle of the 20th century, based on the binary constructions male/female, rational/ irrational and Western/non-Western, in order to formulate the idea of acoustic space as sensual and chaotic, which arose for the perception of rational and ordering of visual space, represented a large project within the Western musical composition: the revival of rational, logical and objective as to the sounding. The use of sound as the main media contributes to the disclosure of the unique possibilities of the art of installation, organically combining the properties of space and place with the characteristics of sound and the specificity of human perception of its various attributes, offering an innovative relationship of acoustic space with its historical, social, narrative, tactile and physical qualities.

Comparison of Techniques to Control Ice Nucleation during Lyophilization

Controlling ice nucleation during lyophilization of parenteral drug products increases the homogeneity of critical quality attributes, such as residual moisture, across drug product batches and shortens lyophilization cycle time. In the present study, we compare three mechanistically different techniques to control ice nucleation during the freezing step of lyophilization, which are referred to as “depressurization”, “partial vacuum”, and “ice fog” techniques. The techniques are compared with respect to their operational limitations and challenges. Installation considerations are also discussed. Using the aforementioned nucleation techniques, we investigated a monoclonal antibody formulation and an enzyme formulation at different protein concentrations using feasible nucleation temperatures and different vial formats and fill volumes. Samples were compared for solid state properties and other critical quality attributes on stability. When nucleated at the same temperature, the three techniques produced products with the same quality attributes and stability behavior. Under conditions resulting in micro-collapse, stability behavior can be different. We found that each technology had considerations for achieving robust nucleation. The present comparison may serve as guidance in selecting a nucleation method.

Recent Advances in Glycerol Catalytic Valorization: A Review

Once a biorefinery is ready to operate, the main processed materials need to be completely evaluated in terms of many different factors, including disposal regulations, technological limitations of installation, the market, and other societal considerations. In biorefinery, glycerol is the main by-product, representing around 10% of biodiesel production. In the last few decades, the large-scale production of biodiesel and glycerol has promoted research on a wide range of strategies in an attempt to valorize this by-product, with its transformation into added value chemicals being the strategy that exhibits the most promising route. Among them, C3 compounds obtained from routes such as hydrogenation, oxidation, esterification, etc. represent an alternative to petroleum-based routes for chemicals such as acrolein, propanediols, or carboxylic acids of interest for the polymer industry. Another widely studied and developed strategy includes processes such as reforming or pyrolysis for energy, clean fuels, and materials such as activated carbon. This review covers recent advances in catalysts used in the most promising strategies considering both chemicals and energy or fuel obtention. Due to the large variety in biorefinery industries, several potential emergent valorization routes are briefly summarized.

Double control method for construction form finding of glass curtain system

An incremental equilibrium equation was deduced for the construction of glass curtain system with inverted-cone curved single-layer cable-net based on the theory of non-linear finite element method. In view of actual influence of glass installation during the construction process, analysis is made on the correction algorithm for formation of non-linear stiffness matrix of structure with consideration of glass installation. The developed algorithm allows for double control over the shape and pre-tension during the construction, and accurate determination of the structural configuration and cable force. Feasibility and accuracy of the method are verified and supported by the case study results.

Mechanical performance of novel steel one-sided bolted joints in shear

This paper introduces an innovative one-sided bolt with ellipse head and examines its mechanical performance based on experimental and numerical studies of double lapped joint configuration. The design of one-sided bolt mechanism and geometry was completed through detailed Finite Element (FE) analysis considering contact behaviours and bolt pre-tensioning. Four bolt head geometries were assessed and comparatively studied in terms of yielding capacity, slip distance and stress concentration; and two bolt diameters and two installation configurations were introduced for each bolt head geometry. Experiments were then conducted based on the specimens manufactured with the optimised geometry for validation of the design and installation considerations, with comparison to ordinary bolts. It was found that the optimal aspect ratio of the ellipse bolt head is about 1.7 and orthotropic installation configuration was recommended. Such innovative one-sided bolts with simple manufacturing and installation sequence exhibit comparable shear performance with ordinary bolts, enabling the use of closed sections for construction with easy assembly and disassembly.

Soil plug heave induced by suction bucket installation on sand via centrifuge model tests

Suction pressure created during suction bucket installation may disturb the surrounding soil and affect its properties. Soil heaving can also occur owing to upward seepage inside the bucket embedded in sand, which hinders soil penetration; however, this mechanism is not well understood. Centrifuge model tests were performed to investigate this soil behaviour and its effect on the installation. Suction pressure, seepage flow, and soil plug heave were monitored under various installation conditions. Bender element and cone penetration tests were also conducted to evaluate the effect of soil plug loosening indirectly. The results illustrate the effects of upward seepage on soil plug heave during suction bucket installation. This study highlights the changes in the soil properties inside the bucket owing to the suction installation. This is an important design consideration for bucket installation, which also affects the bearing capacity of the suction bucket foundation.

Mechanical design of the high-powered helicon antenna and stripline feed in the DIII-D Tokamak

A high-powered “comb-line” helicon antenna for use within the DIII-D Tokamak is currently in design and fabrication at General Atomics. The antenna will drive current in high beta discharges using electromagnetic helicon waves. The high-powered helicon antenna (HPHA) is expected to couple up to one MW of power into DIII-D plasmas at a frequency of 476 MHz. The antenna design includes 30 individual, inductively coupled modules fastened to six internally water-cooled Inconel back-plates. The end modules have special design features to provide RF stripline feed attachment points. Each back-plate is mounted to a pedestal, which is secured to the vessel wall via a combination of studs and welded brackets. The mechanical design includes features to minimize and survive disruption forces, thermal loading from RF losses, vacuum vessel bake (350C), and installation considerations. Thermal stress design challenges include plasma heat loads, thermal ratcheting, and bake-out cycles that result in thermal growth differences between the stripline and the vessel. Splitting the back-plate into six sections each with a central pedestal support significantly reduces the disruption loads. A single stripline folded in half, fed near the fold provides a 180° phase shift between the stripline module connections for driving the two module straps. This looped mono RF coaxial stripline design was chosen to enable using one feed-through, to optimize space limitations, ease of installation, structural rigidity, and RF tuning ability. The striplines are supported by a quarter-wavelength “stub”, mid span, for support during thermal cycling and plasma disruption events. Multiphysics FEA analyses are performed to optimize the geometric shapes to meet the aforementioned design challenges. A description of the mechanical design, fabrication, installation, and analyses of the HPHA and stripline feeds will be presented

Assessing Practice and Criteria for Green Roof Maintenance on High-rise Residential Building in Malaysia

Urbanisation inevitably shows a positive sign in increasing the economic reputation of a country. Nevertheless, it has led to several problems including the deficit in green spaces and destruction of the natural environment, therefore green building is introduced as an alternative to overcome crucial environmental issues. Numerous approaches were also adopted to reduce other environmental issues such as urban heat island, air pollution and lack of green spaces. One of the sustainable approaches that help to minimise the environmental problems is by using the means of vegetation or plant material on rooftops or also known as the green roof. The implementation of the green roof on top of buildings is becoming a trend in the urban cities as it provides numerous benefits to the green development. The green roof is also part of criteria in green building and among the benefits, implementing green roofs will reduce heat flux, optimise energy efficiency and improve stormwater management. However, despite the benefits, enhancement on the green roof installation and maintenance consideration are two factors which are still largely unexplored as the main significant factor in the viability of the green roof installation. Hence, this paper is aimed to determine the vital criteria of maintenance and its ranking towards the establishment of best practice maintenance for the green roof, by focusing on high-rise residential. Questionnaires were distributed by email and through an online survey to 30 maintenance managers of green roof of high-rise residential in Kuala Lumpur and the samples are drawn by using purposive sampling technique. The results showed that the most significant maintenance criteria of the green roof are drainage, followed by waterproofing, irrigation, water retention, and roof slab. The outcome of this study has provided a significant contribution to the current maintenance practice of green roof by prioritising the criteria of maintenance and key address of green roof, where it may help to standardise the maintenance practice of the green roof in the tropical climate of Malaysia.