Passivhaus Institut

Determination of the heat loss coefficient (HLC) of a Passive House – report June 2016

Authors:: Dr. Oliver Ottinger, Dr. Jürgen Schnieders, Dipl.-Ing. Wolfgang Hasper, Dipl.-Ing. (FH) Søren Peper (Passivhaus Institut)
Prof. Dr. Wolfgang Feist, Institut für Konstruktion und Materialwissenschaften der Universität Innsbruck

The building envelope is, beside the building services, the key to reach the Passive House Standard and its high efficiency. As part of the international research project IEA EBC Annex 58 the Passive House institute has examined experimentally the thermal quality of two Passive House buildings. The goal was to show that the planned quality is in concordance with the realized built quality of the thermal envelope of certified Passive Houses.

The thermal quality of a building is mainly determined by the installed insulation, the air tightness and avoiding thermal bridges. The three are some of the Passive House principles.

The Passive House institute has heated both buildings in winter to a constant raised internal temperature electrically (Co-Heating). From the measured electricity consumption the heat loss coefficient [W/K] can be determined. The heat loss coefficient is an important measure that is calculated in the energy balance calculation with the Passive House Planning Package (PHPP). A low value is in concordance with low energy demands for heating.
Results from the Annex 58 project are: The planning is in very good concordance with measured results for the heat loss coefficient for both Passive Houses. The used Co-Heating method is a very good possibility to examine the thermal quality of the building envelope also for highly insulated buildings as Passive Houses excluding the influence of building services and users.

Download ( pdf 4,6 MB) (see pages 140 ff)