Building, Simulation, Zoning, Energy Consumption, TRNSYS
Simulation tools are widely used to assess the energy consumption of a building. In the modeling process, some choices should be made by the simulation tool user such as the division of the building into thermal zones. The zoning process is user dependent, which results in some difference in energy consumption results and model set-up and computational times. The aim of this work is to assess the influence of building zoning on the results of the dynamic thermal simulation including airflow and thermal transfers between zones For this purpose, several different building zonings are applied to the same office building, and then the results of the dynamic thermal simulations are compared in terms of energy consumption (heating, cooling, and auxiliaries) and computational and set-up times. To assess the impact of thermal zoning, five cases are studied (from the most to the least complex): - 1) *49-zone model* : each zone gathers the premises with the same air handling system, the same occupancy profile, at each floor and building orientation. - 2) *44-zone model* : the premises containing the same air handling system are gathered at every floor, even though their occupancy profile is different. - 3) *26-zone model*: all floors are merged, except for the first and the top floors (under-roof). - 4) *21-zone model* : the first and the under-roof floors are merged with the others if the premises have the same occupancy profile and handling system. - 5) *11-zone model* : the premises with a different orientation but with the same occupancy profile and handling system are gathered. The importance of airflow coupling is evaluated by using the most detailed model (49 zones) and comparing the cases with or without considering air transfer from offices to corridors and toilets (from which air is extracted). Then, to study the impact of thermally connecting juxtaposed zones, the “21-zone model” with and without thermal transfer are compared. Finally, the impact of merging the floors is analyzed by considering different roof and floor insulations and the impact of merging the orientations is studied by using different glazed surface ratio.