PhD Thesis - Energy Systems Research Unit - University of Strathclyde

5.1 Effect on thermal demand of improving the building fabricThe first part of this chapter examines the effect of improving the building fabric onthe thermal performance of the building, specifically the effect of improving thebuilding fabric on thermal energy demand. In the analysis, two scenarios areinvestigated; Scenario 1 – the 3 household building and Scenario 2 – the 6 householdbuilding. For both scenarios two different building fabric cases were developed, alow efficiency fabric case (Scenario 1 Low and Scenario 2 Low ) representing currentMaltese housing and a high efficiency fabric case (Scenario 1 High and Scenario 2 High )representing future Maltese housing; these were used to analyse the effect ofimproving the building fabric on the heating and cooling load of the two buildingsmodelled. Inter-scenario comparisons were also undertaken, to examine theinteraction between improving the building fabric and building size and occupancy.In this first set of results presented, the annual amount of heating and cooling energysupplied to the two building models by the basic micro-trigeneration plantconfiguration (shown in Figure 3.2) are listed and discussed. In the case of the 3household building the control scheme used is that shown in Table 3.5, whilst for the6 household building the control scheme used is that shown in Table 3.6. Based onthe data extracted from the four sets of simulations, equation (4.1) was used tocalculate E SH in kWh, the energy supplied for space heating, whilst equation (4.2)was used to calculate E SC in kWh, the energy supplied for space cooling. Thesesimulations quantify the effect of fabric improvements on building space heating andcooling thermal demand and are eventually used to quantify the effect building fabrichas on the performance of a micro-trigeneration system.5.1.1 Analysis of space conditioning energy requirements – Heating periodTable 5.1 lists the annual heating energy supplied for the four scenarios. As would beexpected, the simulation results show that the heating load for the 6 householdbuilding is significantly higher than for the 3 household building. The load perhousehold is however actually lower (825 kWh/household compared to 1,103kWh/household in the low efficiency case and 536 kWh/household compared to 857kWh/household in the high efficiency case), demonstrating that as housing density165