Kassim Gidado

Simulated Performance of Earthtube for Cooling of Office Buildings in the Southeast of UK

Using the ground-air heat exchanger to reduce the temperature fluctuations of the outdoor air supply to a building is a potential sustainable low carbon emissions building design option where suitable site conditions exist. Although the basic concept of this technology is simple and some thermal models already exist, there is no integrated design tool or published data that can be used directly to predict their dynamic thermal performance. This research reviewed the current state of the art on the thermal models of earthtubes and thermal performance prediction tools. Available soil temperature profiles and earthtube thermal models were evaluated, selected and adopted in component based dynamic thermal simulation software Transient System Simulation Environment (TRNSYS). A system network representing the configuration of a proposed system can be establish which enables parametric and system study of the dynamic thermal behaviour. This computer simulation tool was applied to study the application of earthtube to maintain the summer thermal comfort of an office located at the southeast of UK. The results showed an optimized system configuration with the appropriate pipe diameter, pipe length and airflow rates are necessary to maintain the comfort conditions in the summer.

Risk management: the relationship between perceived risk factors of crowd disaster and perceived safety in large buildings

Poor risk management within large buildings such as sport stadiums, concert halls, and religious buildings have resulted in crowd disasters in various venues across the world. Within the built environment, safety is considered in two main parts: objective safety (normative and substantive) and subjective safety (perceived). Facilities management within large buildings used by large crowds must involve effective risk management as a key component. Fruin suggested that Force, Information, Space and Time (FIST) are the main factors that influence the occurrence of crowd disaster. It has also been theorised that poor perceived safety alone could result into crowd disaster. By using the FIST model, this paper investigates the relationship between the four critical FIST factors and perceived safety in large buildings. The research chose to use the Holy Mosque in Makkah as a case study. The Holy Mosque is a large building of 356,800 m2 with a maximum capacity of two million users (pilgrims). Data was collected using iPad devices via a self-administered questionnaire distributed to 1940 pilgrims of 62 different nationalities. The results were analysed using SPSS for descriptive analysis and AMOS 22 for Structural Equation Modelling (SEM). The findings clearly confirmed that there is a significant relationship between the FIST factors and perceived safety in large buildings. These findings will inform design consultants and facilities managers as they design and/or manage such facilities.

Confirmatory factor analysis of perceived risk factors for crowd safety in large buildings

In large buildings or spaces used for large events, crowd safety is one of the most important concerns for facilities management. In the past decades, there have been crowd disasters in venues such as sport stadiums, concert halls, and at religious events the world over. The user of such facilities during mass gatherings can be exposed to health and safety risk, which can be mitigated by using effective risk management as a component of facilities management. A lot of emphasis is given to objective safety, but research has shown that the user’s perceived (subjective) safety is also an important factor that cannot be overlooked. This research has identified the crowds’ perceived risk factors for a selected large space facility. The paper applied confirmatory factor analysis to test the theoretical pattern of the variables loading on a developed construct to show how well these factors match reality. Twelve perceived risk factors to crowd safety have been verified.