PhD Thesis - Energy Systems Research Unit - University of Strathclyde

2.1 Modelling residential demand - Characterisation of a building throughits energy requirementsThe energy demand of a residential building can be divided into two basic categories,the electrical and thermal demands. The electrical demand relates to the aggregatedelectrical load of appliances and lighting, whilst the thermal demand accounts for theenergy demand for water heating and space conditioning. In the latter case, theenergy required for space heating and/or cooling is the result of multiple drivers (e.g.climate, building characteristics, shading, internal heat gains, solar gains etc.), someof which are interrelated and dependent on one another.The use of a whole building, dynamic simulation tool such as ESP-r [1] is anappropriate means to calculate these energy demands, in that, it can be used togenerate demand data whilst accounting for the temporal interactions betweenclimate, the building fabric, the building occupants and the energy systems (boththermal and electrical). Before going into detail explaining how demand data isobtained, the next section briefly explains the modelling process adopted when usingESP-r [1]. The section also gives specific details as to how the various inputs andoutputs required for analysis of trigeneration systems were obtained.2.2 The building simulation tool ESP-rAs discussed in Chapter 1, the building simulation tool used in this research is theenergy modelling tool ESP-r. Various studies (e.g. [2-4]) explain the conceptsunderpinning ESP-r, including more in-depth explanations of the control volumeprinciple used by the tool to model building and plant systems. Hence, what followsis a brief overview of the basic concepts and fundamental principles, which willenable the reader to follow the model development and modelling activitiesdescribed in subsequent sections.2.2.1 A quick user guide to modelling combined building and plant systems usingESP-rFigure 2.1 shows a simplified ESP-r input and output process. Similarly to otherbuilding simulation tools, ESP-r permits the modelling of complex buildings and the28