Dear all,
My question seems to be simple but has preoccupied me for a while:
Is it a credible approach to calculate annual cooling demand (using the idealLoadsAirSystem) for a naturally ventilated zone (with cooling system operation and natural ventilation at the same time)?
One may argue that when a zone is being air conditioned, the occupants are not supposed to naturally ventilate the room (and if they do, it increases the cooling demand). Therefore it does not make sense to conduct such a simulation and talk about cooling demand as a performance indicator for naturally ventilated buildings.
But, as far as I know, in EnergyPlus, at each time step first the room air is mixed with the specified amount of outdoor air provided via natural ventilation or infiltration, and then the ideal system calculates the required cooling energy to cool the indoor air down to the cooling set point.
If so, would it be valid to use a ZoneVentilainDesignFlowRate object (with appropriate temperature thresholds to activate natural ventilation) and Ideal load air system to see the potential of natural ventilation in reducing the building cooling demand?
I would be very grateful, if you comment on this.
Regards,
Farhang
Farhang Tahmasebi
University Assistant, MSc
TU Wien
Department of Building Physics & Building Ecology
Karlsplatz 13, 1040 Vienna, Austria
Tel: +43 1 58801 270 31
e-mail: farhang.tahmasebi@xxxxxxxxxxxx