Theoretical and real ventilation heat losses and energy performance in low energy buildings

Ventilation in low energy refurbished buildings is the cause of a big part of energy losses. In order to reduce this impact, some energy regulations prescribe a solution (such as the Swiss energy Law, prescribing heat recovery) and others prescribe a system global performance (such as the EU delegated regulations No 1254 and 1253 /  2004 determining a global energy performance label of the ventilation system).

Re heat recovery systems necessary for nearly zero energy buildings in mild climates?

Heat recovery ventilation became an unavoidable element of a passive or nearly zero energy building in Northern and Central Europe countries. Airtightness standards became very tight so that the building is compatible with this ventilation system. As frosting of heat recovery unit consumes a lot of electrical energy, a buried pipe system to smooth air temperature variations became also a necessary system in order to avoid defrosting.

Market transformation towards nearly zero energy buildings through widespread use of integrated energy design

ID is a design procedure that considers the building as a whole system with the aim of optimizing it throughout the lifecycle. ID can be used to reach high ambitions by developing, discussing and evaluating a scheme using a multidisciplinary team from the initial design phases and it is a proven approach for achieving high-performance buildings with good indoor environment without sacrificing architectural quality or result in excessive costs. Integrated Design support designers in delivering buildings which satisfy occupant’s needs much more than conventionally designed buildings.