Natural ventilation and dynamic temperature simulation of buildings was until now a priviledge of highly skilled building physicists. Combined simulation of both is even rarer.
A new software approach guiding the user to construct rapidely, easyly and intuitively step by step a valid thermal model, makes passive cooling design affortable to any building designer, even to a non building physics experts. Dial+ software offers the possibility to sumulate for the same room natural ventilation air flow, dynamic thermal behaviour and natural lighting performance. Behind its intuitive interface, Radiance for natural lighting, Cocroft algorithm for natural ventilation and EN ISO 13791 indoor air dynamic simulation give answers to the designers questions in order to optimise design and meet passive building specifications.
The article presents how the software was employed to optimise two similar office buildings situated one in Geneva and one in Nicosia. Both buildings consume less than 40 kWh/m2 of primary energy. The results show how essential is night cooling in both mediteranian and central Europe climates and quantify the contribution of passive techniques (insulation, glazing performance, solar shading, thermal mass etc) to the high energy performance. Both buildings were constructed and the performances verified in practice.