TY - RPRT
T1 - Passive Cooling of buildings by night-time ventilation
AU - Artmann, Nikolai
AU - Manz, Heinrich
AU - Heiselberg, Per
N1 - BFE Projekt-/Vertrag-Nummer 101'308, www.energieforschung.ch
PY - 2008
Y1 - 2008
N2 - Due to an overall trend towards an increasing cooling energy demand in buildings in many European countries over the last few decades, passive cooling by night-time ventilation is seen as a promising concept. However, because of uncertainties in thermal comfort predictions, architects and engineers are still hesitant to apply passive cooling techniques. As night-time ventilation is highly dependent on climatic conditions, a method for quantifying the climatic cooling potential was developed and the impact of climate warming was investigated. Although a clear decrease was found, significant potential will remain, especially if night-time ventilation is applied in combination with other cooling methods. Building energy simulations showed that the performance of night-time ventilation is also affected by the heat transfer at internal room surfaces, as the cooling effect is very limited for heat transfer coefficients below about 4 W/m2K. Heat transfer during night-time ventilation in case of mixing and displacement ventilation was investigated in a full scale test room at Aalborg University. In the experiments the temperature efficiency of the ventilation was determined. Based on the previous re-sults a method for estimating the potential for cooling by night-time ventilation during an early stage of design was developed.
AB - Due to an overall trend towards an increasing cooling energy demand in buildings in many European countries over the last few decades, passive cooling by night-time ventilation is seen as a promising concept. However, because of uncertainties in thermal comfort predictions, architects and engineers are still hesitant to apply passive cooling techniques. As night-time ventilation is highly dependent on climatic conditions, a method for quantifying the climatic cooling potential was developed and the impact of climate warming was investigated. Although a clear decrease was found, significant potential will remain, especially if night-time ventilation is applied in combination with other cooling methods. Building energy simulations showed that the performance of night-time ventilation is also affected by the heat transfer at internal room surfaces, as the cooling effect is very limited for heat transfer coefficients below about 4 W/m2K. Heat transfer during night-time ventilation in case of mixing and displacement ventilation was investigated in a full scale test room at Aalborg University. In the experiments the temperature efficiency of the ventilation was determined. Based on the previous re-sults a method for estimating the potential for cooling by night-time ventilation during an early stage of design was developed.
M3 - Report
BT - Passive Cooling of buildings by night-time ventilation
PB - Schlussbericht. Eidgenössisches Departement für Umwelt, Verkehr, Energie und Kommunikation, UVEK. Bundesamt für Energie BFE
CY - Duebendorf
ER -