A parametric building energy simulation case study on the potential and limitations of passive design in the Mediterranean climate of Malta

Heinrich Manz,Vincent Buhagiar,Simon Paul Borg,Daniel Micallef

doi:10.1051/sbuild/2018004

Heinrich Manz, Vincent Buhagiar + Show 2 more

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https://doi.org/10.1051/sbuild/2018004

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Abstract

The present case study sets out to investigate the potential and limitations of passive building design in a typical Mediterranean climate. The Maltese Islands were taken as the case study location. Assuming a fully detached, cuboid-shaped, generic multi-storey office building, one representative storey was modelled by means of the building energy simulation code WUFI®Plus. Thermal comfort was analysed based on the adaptive acceptable operative room temperature concept of EN 15251 for buildings without mechanical cooling systems. Assuming neither artificial heating nor cooling, the free-running operative room temperature was evaluated. By means of a parametric study, the robustness of the concept was analysed and the impact of orientation, window to wall area ratio, glazing, shading, thermal insulation, nighttime ventilation and thermal mass on the achievable level of thermal comfort is shown and discussed. It is concluded that in a well-designed building and by means of decent insulation (present case: Uwall = 0.54 W/(m2 · K)), double glazing, variable external shading devices and passive cooling by nighttime ventilation, a high level of thermal comfort is achievable in this climate using only very minor amounts of energy for artificial heating and cooling or possibly even none at all.

Highlights

Buildings account for 40% of the total energy consumption in the European Union and, reduction of energy consumption and the use of energy from renewable sources in the buildings sector constitute important measures needed to reduce the EU’s energy dependency and greenhouse gas emissions [1]
It is concluded that in a well-designed building and by means of decent insulation (present case: Uwall = 0.54 W/(m2 · K)), double glazing, variable external shading devices and passive cooling by nighttime ventilation, a high level of thermal comfort is achievable in this climate using only very minor amounts of energy for artificial heating and cooling or possibly even none at all
The results showed that nighttime ventilation is the most effective strategy for passive cooling in vernacular dwellings during the hot summer period, compared with other ventilation strategies

Summary

Introduction

Buildings account for 40% of the total energy consumption in the European Union and, reduction of energy consumption and the use of energy from renewable sources in the buildings sector constitute important measures needed to reduce the EU’s energy dependency and greenhouse gas emissions [1]. In Malta, a small archipelago on the 36° parallel of latitude in the central Mediterranean Basin with a total population of 445,426 [2] and the most densely populated EU member state (1410/km2) [3], the building sector constitutes about 35% to the total energy consumption [4] with cooling contributing more than heating [5], due to the prolonged summer season. Given that Malta only joined the European Union in 2004, the transposition of the EPBD materialised soon enough in 2006. Centralised space conditioning systems are very popular in large-scale office buildings, but typically uncommon in dwellings

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