The analysis presented in this paper is dealing with the correct and energy efficient measures of cooling buildings through nocturnal natural ventilation. Using this solution is proved in this article to be efficient and can reduce substantially the cooling demand. In order to establish the factors influencing the process of passively cooling a building (the ventilation volume, exterior temperature, thermal capacity of the building, possible duration of the ventilation), we have chosen different buildings, which we have placed them in different temperature zones of Romania. The study is based on multiple simulations realized with a time step of one hour, with the following variations: the climatic parameters, the thermal characteristics of the building, the air flow during night time, the proposed interior temperature. Since the study consisted of numerous simulations, in order to treat the results we have used statistical methods that cover the practical and possible situations, and proved the efficiency of nocturnal ventilation.
 Colda, I. (2014). Ventilarea si consumul de energie. Energy Performance of Buildings. Bucuresti, from http://www.aiiro.ro.
 Ralf Cavelius, I. (2014). Passive Cooling. Viena: Austrian Energy Agency, from http://citeseerx.ist.psu.edu.
 IEA-EBC project annex 62. (2012), from www.iea-ebc.org, http://www.iea-ebc.org/projects/ongoingprojects/ebc-annex-62/
 IEA EBC. (2017). Feedback from the IEA. Venticool the international platform for ventilative cooling, The Executive Committee of the IEA Energy in Buildings and Communities programme, Newsletter no.9.
 Kolokotsa, M. S. (2013). Passive cooling dissipation techniques for buildings and other structures: The state of the art. 1st venticool Conference, 25-26 September 2013, Athens, from http://www.aivc.org/resource/passivecooling-dissipation-techniques-buildings-and-other-structures-state-art.
 Hassid, S. (2013). Individual appreciation of air conditioned surroundings. 1st venticool Conference, p. 3rd TightVent. 25-26 September 2013, Athens, 74.1367313206.
 Edna Shaviv, A. (2001). Thermal mass and night ventilation as passive cooling design strategy. Renewable Energy.
 Finn, D. (2005). Sensitivity analysis of a maritime located night ventilated library building. International Conference “Passive and Low Energy Cooling for the Built Environment”, Santorini, Greece.
 Akbari, H. D. (1986). The effect of variations in convection coefficients on thermal energy storage in buildings Part I - Interior partition walls. Energy and Buildings.
 Virgone, J. N. (2009). Numerical study of the influence of the thickness and melting point on the effectiveness of phase change materials:application to the renovation of a low inertia school. Eleventh International IBPSA Conference, Building Simulation. Glasgow, Scotland.
 KoZiBu - Simulation Dynamique d'un Bâtiment, from http://www.jnlog.com/kozibu1_fr.htm
 Administratia Nationala de Meteorologie, (2016). Scenarii climatice, from http://www.meteoromania.ro/.
 Sun Position. (2012). From http://www.sunearthtools.com.
Bucuresti. (2012), from https://www.wunderground.com/ro/