Abbas Elmualim

BIM: innovation in design management, influence and challenges of implementation

The construction industry is widely being criticised as a fragmented industry. There are mounting calls for the industry to change. The espoused change calls for collaboration as well as embracing innovation in the process of design, construction and across the supply chain. Innovation and the application of emerging technologies are seen as enablers for integrating the processes ‘integrating the team’ such as building information modelling (BIM). A questionnaire survey was conducted to ascertain change in construction with regard to design management, innovation and the application of BIM as cutting edge pathways for collaboration. The respondents to the survey were from an array of designations across the construction industry such as construction managers, designers, engineers, design coordinators, design managers, architects, architectural technologists and surveyors. There was a general agreement by most respondents that the design team was responsible for design management in their organisation. There is a perception that the design manager and the client are the catalyst for advancing innovation. The current state of industry in terms of incorporating BIM technologies is posing a challenge as well as providing an opportunity for accomplishment. BIM technologies provide a new paradigm shift in the way buildings are designed, constructed and maintained. This paradigm shift calls for rethinking the curriculum for educating building professionals, collectively.

Wind Tunnel and CFD Investigation of the Performance of “Windcatcher” Ventilation Systems

Abstract Experimental investigations and CFD simulations were carried out to evaluate the performance of square and circular section wind-driven systems for natural ventilation applications in buildings. Wind tunnel and smoke visualisation tests were conducted on a full-scale model based on a commercial “windcatcher” design. The experimental set-up consisted of each system being connected to a model test room. The devices are divided internally into four quadrants/segments for the purpose of air supply and extract. Pressure coefficients distribution, internal air speed and volumetric air flow rate were measured for various wind speeds and for different wind directions. In addition, CFD simulations were carried out to obtain the pressure distribution and air flow pattern around the square section system. The results show that the performance of the devices depends mainly on the speed and direction of the prevailing wind. Although the ventilation rate increases with wind speed it was found to decrease with the increase in the wind direction angles from 0° to 45°, measured from the normal to the face of the square system.

Dynamic modelling of a wind catcher/tower turret for natural ventilation

This paper discusses experimental and theoretical investigations and Computational Fluid Dynamics (CFD) modelling considerations to evaluate the performance of a square section wind catcher system connected to the top of a test room for the purpose of natural ventilation. The magnitude and distribution of pressure coefficients (Cp) around a wind catcher and the air flow into the test room were analysed. The modelling results indicated that air was supplied into the test room through the wind catchers quadrants with positive external pressure coefficients and extracted out of the test room through quadrants with negative pressure coefficients. The air flow achieved through the wind catcher depends on the speed and direction of the wind. The results obtained using the explicit and AIDA implicit calculation procedures and CFX code correlate relatively well with the experimental results at lower wind speeds and with wind incidents at an angle of 08. Variation in the Cp and air flow results were observed particularly with a wind direction of 458. The explicit and implicit calculation procedures were found to be quick and easy to use in obtaining results whereas the wind tunnel tests were more expensive in terms of effort, cost and time. CFD codes are developing rapidly and are widely available especially with the decreasing prices of computer hardware. However, results obtained using CFD codes must be considered with care, particularly in the absence of empirical data. Practical application: There exist various modelling techniques for the investigation of the performance of natural systems such as wind catchers. These modelling techniques include simple calculation procedures, wind tunnel testing, salt bath, Computational Fluid Dynamics (CFD) and real building performance (POE studies). The calculation procedural models are simple to use, however, due to their simplicity they do not provide a full picture of the performance of the natural ventilation system and air movement inside rooms. Other models such as wind tunnels and CFD are more comprehensive but expensive and time consuming to use. Various commercial CFD models are available in the market today and not many of them are specifically designed for modelling of natural ventilation. Results obtained using CFD models should be considered with care specially in the absence of empirical data and if the results were obtained by novice users. Wind catchers are innovative techniques for the application of natural ventilation in buildings in temperate climates such as that of the UK. Their performance greatly depends on wind conditions. However, they should be designed as an integral part of the overall design of the HVAC system in a hybrid or mixed mode operation. The natural ventilation system of wind catchers should be exploited whenever possible, particularly in the hot summer months to reduce the energy and environmental cost of full operation of an air-conditioning system.

Evaluation of dichroic material for enhancing light pipe/natural ventilation and daylighting in an integrated system

Integration of natural ventilation and daylighting in a single installation would make both technologies more attractive. One method for the integration is the use of concentric light pipe and ventilation stack. By constructing the light pipe using dichroic materials, the infrared part of the solar radiation is allowed to be transmitted to the stack but the visible light is guided by the light pipe into a room. The heat gain to the interior can be reduced and the thermal stack effect strengthened. Work presented here involved the experimental and computational evaluation of dichroic materials for enhancing both natural stack ventilation and daylighting. The transmittance of a dichroic light pipe was found to be similar to that of a light pipe with a 95% specular reflectance. The infra-red radiation transmitted through the dichroic material into a passive stack was found to enhance the natural ventilation flow by up to 14%. The effect is greater in summer than in winter, which is highly desirable as there is often a lack of driving force for natural stack ventilation in summer.

Verification of Design Calculations of a Wind Catcher/Tower Natural Ventilation System with Performance Testing in a Real Building

Abstract A wind catcher/tower natural ventilation system was installed in a seminar room in the building of the School of Construction Management and Engineering, the University of Reading in the UK. Performance was analysed by means of ventilation tracer gas measurements, indoor climate measurements (temperature, humidity, CO2) and occupant surveys. In addition, the potential of simple design tools was evaluated by comparing observed ventilation results with those predicted by an explicit ventilation model and the AIDA implicit ventilation model. To support this analysis, external climate parameters (wind speed and direction, solar radiation, external temperature and humidity) were also monitored. The results showed the chosen ventilation design provided a substantially greater ventilation rate than an equivalent area of openable window. Also air quality parameters stayed within accepted norms while occupants expressed general satisfaction with the system and with comfort conditions. Night cooling was maximised by using the system in combination with openable windows. Comparisons of calculations with ventilation rate measurements showed that while AIDA gave reasonably correlated results with the monitored performance results, the widely used industry explicit model was found to over estimate the monitored ventilation rate.

Mirror lightpipes : Daylighting performance in real buildings

Mirror lightpipes are useful for providing healthy and energy-efficient daylight into buildings where windows and skylights are unsuitable, insufficient or generate too much heat gain. The lightpipes have been installed in dozens of buildings in the UK. Field monitoring has been carried out to assess their performance in four different buildings: the headquaters of a major insurance company, a health clinic, a residential building and a college dining hall In those cases where lighipipes with moderate aspect ratios were installed, good illuminance of up to 450 lux has been obtained with internal/external illuminance ratios around 1%. When long and narrow lightpipes with many bends are used, however, the ratio reduced to around 0.1%. These results showed that lightpipes can be effective daylighting devices provided that excessive aspect ratios and numbers of bends are avoided. Lightpipes with larger diameters should be used whenever possible. The lightpipes often improved signiScantly the visual quality af the interior environment, and high user satisfaction was found even in buildings where a relatively low level of daylight was admitted through the lightpipes

Linking energy and maintenance management for sustainability through three American case studies

Purpose – The purpose of this paper is to present the findings and lessons learned from three case studies conducted for facilities located in California, North America. The findings aim to focus on energy and maintenance management practices and the interdependent link between energy and maintenance.Design/methodology/approach – The research is based on a positivist epistemological philosophical approach informed by action research. The research cycle was completed for each case study. A case study report was provided to each facility management team to foster collaboration with the researcher and to document case study process and results.Findings – Composite findings of the case studies include: there is an interdependent link between energy and maintenance management; reactive maintenance and energy management methods are commonly used; and more proactively operated and managed buildings require the interdependent link between energy maintenance management to be better understood.Research limitations/...

Application of computer‐aided facilities management (CAFM) for intelligent buildings operation

Purpose – The purpose of this paper is to investigate the concepts of intelligent buildings (IBs), and the opportunities offered by the application of computer‐aided facilities management (CAFM) systems.Design/methodology/approach – In this paper definitions of IBs are investigated, particularly definitions that are embracing open standards for effective operational change, using a questionnaire survey. The survey further investigated the extension of CAFM to IBs concepts and the opportunities that such integrated systems will provide to facilities management (FM) professionals.Findings – The results showed variation in the understanding of the concept of IBs and the application of CAFM. The survey showed that 46 per cent of respondents use a CAFM system with a majority agreeing on the potential of CAFM in delivery of effective facilities.Research limitations/implications – The questionnaire survey results are limited to the views of the respondents within the context of FM in the UK.Practical implication...

Innovation in facilities management: from trajectories to ownership

Purpose – Innovation in facilities management (FM) is a complex process as FM is a diverse discipline. This paper aims to use innovation trajectories to explore this complex process through the introduction of a technology innovation in two FM services of security and workspace management. It also aims to consider the discourse of individuals within their trajectory to understand their positions toward the innovation.Design/methodology/approach – A two‐year case study was conducted and it was based in an in‐house FM department that was part of a financial institution. The specific methods used for the paper were semi‐structured interviews with key participants of the project. Critical discourse analysis was used to examine the data.Findings – Individuals who were involved in introducing the technology to the FM department were both internal and external to FM as innovation in FM does not happen in isolation to the organisation. Innovation trajectories were often intertwined or occurred simultaneously duri...

Performance Evaluation of a Wall Mounted Convector for Pre-heating Naturally Ventilated Spaces

Abstract This paper presents the results of performance monitoring under real winter weather conditions, controlled laboratory testing and computational fluid dynamics (CFD) analysis of a wall mounted ventilation air inlet heat convector. For real winter weather monitoring, the wall-mounted convector was installed in a laboratory room of the Engineering Building of the School of Construction Management and Engineering. Air and hot water temperatures and air speeds were measured at the entrance to the convector and in the room. The hot water temperature was controlled at 40, 60 and 80 °C. The monitoring results were later used as boundary conditions for a CFD simulation to investigate the air movement in the room. Controlled laboratory testing was conducted in laboratories at the University of Reading, UK and at Wetterstad Consultancy, Sweden. The results of the performance investigation showed that the system contributed greatly to the room heating, particularly at a water temperature of 80 °C. Also adequate fresh air was supplied to the room. Such a system is able to provide an energy efficient method of eliminating problems associated with cold winter draughts.