PhD Thesis - Energy Systems Research Unit - University of Strathclyde

3.1 Control strategies for the indoor air temperaturesChapter 2 explained that in order to ensure better temperature control of theindividual apartments, each apartment in the two buildings modelled (the 3 and the 6household building) was divided into two zones, a living area and a bedroom areazone. For each individual zone a different control strategy was adopted for both theheating and cooling season, based on whether that particular zone was occupied ornot. The temperature controlled periods during which the indoor temperature in eachzone was controlled, was based on the occupancy. Living area zones were assumedto be occupied between 7 in the morning and midnight (except when the occupancyprofile dictated that the apartment was vacant), whilst bedroom area zones wereconsidered to be occupied from midnight till 7 in the morning. This is typical of a‘working family’ profile in Malta [1].3.1.1 Heating season set control temperaturesThe thermally controlled time periods and (heating season) temperature limits for theindividual zones in the 3 household building were set as shown in Table 3.1. Theheating season was assumed to start on the 17 th of December and finish on the 19 th ofMarch, a 92 day period chosen on the basis of similar heating season durations usedfor other Mediterranean countries [2].Determining with exact precision when heating is required in residential buildings isdifficult given that, in their own domestic environment occupants tend to have muchbetter control of both the surrounding environment and the way they adjust to it,compared to being in public places [3]. Their adaptability is therefore much higher.For example, although people might be inside and according to comfort theory(Fanger [4]) heating may be required, heating may still not be used, as the occupantswould adjust (e.g. by changing clothes, drinking warm beverages etc.). Based on thefact that the daily mean temperatures tend to be lowest during the evening, in thisresearch it was assumed that heating was needed predominantly around this time ofthe day, with the start time being when the apartment would become occupied afterbeing left vacant during the day. Although as reported by Peeters et al. in [3], theWorld Health Organisation recommends a minimum bedroom temperature of 16°C,91