DYNAMIC BUILDING ENERGY SIMULATION

Following the survey campaign in the case study building and in parallel with the previous activities, the thermal-energy dynamic simulation model of the building was developed. The purpose of this analysis is the complementary assessment on the role of occupant behavior for building energy efficiency and the evaluation of the achievable energy saving and comfort conditions in the case study building thanks to the triggering campaign. The dynamic simulation model of the case study building was developed within EnergyPlus simulation environment with DesignBuilder graphical interface, according to the technical information provided by the partner company of the project. Regarding the occupancy and occupant behavior schedules, the presence during the week and during the day was modeled according to the answers of the questionnaire.

Firstly, the annual energy performance of the case study building was analyzed in the actual configuration (Scenario_actual). The focus was on the office area. In the actual configuration, the inputs and settings for the control of building interfaces by the occupants were set based on the information collected during the monitoring and survey campaigns. The unavailable information was set based on the existing standards and requirements. In particular, the set-point temperature for cooling was set equal to 24.5°C (based on the monitored data), while the set-point temperature for heating equal to 21°C (based on the recommendations of the standard EN 15251:2007). Moreover, the monitored indoor microclimate data appear to suggest that the office occupants hardly ever open windows.Therefore, in this scenario natural ventilation was set equal to 0 ac/h, namely windows always closed.Thereafter, the effect on building energy efficiency of different occupants’ comfort adaptation behaviors simulating the effects of the triggering campaign were modeled. They were defined based previous research studies and on the results of the questionnaire survey. In detail, the following occupant behavior adaptation scenarios were modeled:

• Scenario_HVAC: variation of set-point temperature for cooling and heating, set 1°C higher than the one monitored in the case study building and 1°C lower, respectively;
• Scenario_ventilation: variation of natural ventilation to “minimum fresh air per person”.

At this stage, only these two adaptive behaviors were modeled since they were demonstrated to be among the most occupant-related influencing factors on building energy performance by previous studies.
Finally, the results of the different occupant behavior scenarios for the office area of the case study building were compared in terms of annual primary energy requirement for heating and cooling (since the proposed occupant adaptation scenarios mainly influence these energy consumption components). The statistical weather file used for the calculations is the one for the city of Perugia, Italy, IGDG (Italian Climatic data collection “Gianni De Giorgio”), i.e. the closest available provided in the EnergyPlus weather file database.