TITLE:
Conscious Use of the Virtual Sphere Modeling in the Simulation of Passive Night Cooling of Buildings
AUTHORS:
Marco Simonetti
KEYWORDS:
Night Cooling of Buildings, Natural Ventilation, Virtual Sphere Modelling, CFD
JOURNAL NAME:
Open Journal of Energy Efficiency,
Vol.5 No.2,
June
22,
2016
ABSTRACT: Night cooling of building is considered as a technology with a high potential of impact on air conditioning energy needs. Natural ventilation should be the first option for night cooling, for obvious reasons of energy savings. The evaluation of the capacity of the building to cool down its structures during night ventilation is of primary concern during preliminary design stage, even though night cooling with natural ventilation is among the most complex problem to be modelled in details. Some modelling options are available, assuming different simplifications in space and time. Among them, virtual sphere modelling has been proposed in the past as a quick way to perform dynamic simulation of the night cooling of buildings. In this paper, the theoretical origin of the virtual sphere model is recalled, underlining its limits in case of application to buoyancy driven night cooling of buildings. The limits can explain the disagreements of virtual sphere prediction with other methods reported in literature and may stimulate a more conscious application of the model and further improvements of the method.