Passive Night Cooling Potential in Office Buildings in Continental and Mediterranean Climate Zone in Croatia

Abstract

The envelope is one of the most important driving factors in the energy efficiency of buildings. Typical for office and commercial buildings, curtain wall facades allow solar heat gains to be used during the winter but can lead to difficulties in reducing the cooling load during summer. The cooling load is dominant in most building types in the temperate maritime climate, while in the temperate continental climate, it is dominant mainly in office and commercial buildings. The goal of this research was to determine the potential of night passive cooling in an office building model in the most populated urban areas in Croatia-Zagreb and Split, which are located in two different climate zones. Suitable to the climate on-site, an appropriate building envelope and various types of passive and mechanical ventilation systems were selected for each location and case. Additional factors included and analysed were climate conditions, heat gains, the heat accumulation of the building, night ventilation through openings, unwanted air infiltration, and cooling loads. Through a detailed description of the model, passive cooling potential calculations, and Computer Fluid Dynamics (CFD) simulations, the results showed a potential of up to 43.5% savings in the cooling energy need for the temperate continental climate and 32.2% in the temperate marine climate. It was found from the analysis that night ventilation is expected to cool down the building enough to delay a need for cooling by several hours and improve fresh air requirements, thus saving power for cooling, and effectively reducing the need for air conditioning.

An Environmental Quality Assessment of Office Buildings: The Impact of a Glass Façade on Users in Different Climate Contexts in Croatia

“…The analysis of the climate characteristics of the two cities reveals that the office buildings in Split are exposed to significantly higher solar radiation and higher temperatures compared to the buildings located in Zagreb, especially during the summer period. The mentioned parameters can affect the selection of the type and material of the façade, the energy efficiency of the building [75], and the comfort of staying in the interior space of the building.…”

“…The field of office glass façade energy efficiency research [3,4,8,9,19,[42][43][44][45][46][47] and indoor environmental quality [6,15,16,[18][19][20][21][22][23]27,28,[30][31][32][33]35,36,38,39,41,45,[48][49][50][51][52][53][54] is extensive. Numerous studies focus on the combination of the research into the energy efficiency of a façade and its impact on user comfort in certain climate contexts [3,5,7,8,12,18,26,28,34,55,56].…”

Simulation and Experimental Study on the Use of Ventilation Air for Space Heating of a Room in a Low-Energy Building

“…Ventilation loss was included in the energy demand for space heating and cooling, but no information on considered ventilation systems was provided. Veršić et al [41] simulated night passive cooling in an office building depending on the wind velocity using the building model of 3D Studio MAX 2016 and CFD Simscale software. Hourly energy simulations were performed implementing the hourly method of EN ISO 52016-1 [42] in Visual Basic 2017.…”