PhD Thesis - Energy Systems Research Unit - University of Strathclyde

(as discussed by Richardson et al. in [28]) most of the variations in electrical demandtake place when occupants are indoors and active. In Figure 2.32 the large variationsin demand after 17.00 Hours and the stable demand between 09.00 and 17.00 Hours(the only loads present are the constant base load and the cyclic demand of therefrigerator) concur with this conclusion, suggesting that effectively between 09.00and 17.00 Hours the apartment is vacant whilst most of the occupants are activelypresent after 17.00 Hours.The occupancy profile modelled using Richardson’s interactive tool was extended toaccount for heat emissions when people are not active (i.e. asleep). By usingRichardson’s approach [56], there is no way in which one can distinguish thedifference between an apartment being empty or the apartment’s inhabitants beingasleep. Therefore, a reasonable assumption, based on the ‘time-use survey’ used byRichardson et al. is to assume that during the night all occupants of a particularhousehold are inside the building. Figure 2.33 shows the adjusted occupancy profileto account for when people are asleep.Fig. 2.33 - Adjusted occupancy profileBased on the modelled occupancy pattern the internal heat gains profile for eachindividual household can therefore be modelled by awarding default values forsensible and latent heat gain set by ASHRAE in [11] based on the number ofoccupants present during any specific time. This resulting internal heat gain profiledue to occupants is shown in Figure 2.34.72