Using the PASSYS cell for model-to-model comparison of hygrothermal building envelope simulation tools

IEA-EBC Annex 68 “Indoor Air Quality Design and Control in Low Energy Residential Buildings” is an international collaborative project to provide new insight into methods and strategies for ensuring high indoor air quality in dwellings during both design and operation phase of their life cycle. Within the Annex 68 work, we defined a common exercise, which focusses on model-to-model comparison of different simulation tools to assess their modelling abilities with respect to combined heat, moisture and pollution transfer.

As basis of the common exercise, we selected a model of the PASSYS cell (originally used as a common European outdoor test facility for thermal and solar building research). The PASSYS cell is modelled by using several simulation tools with different modelling capabilities (e.g. 2D hygrothermal building envelope models vs. 3D building energy models).

Model comparisons are done at stepwise increased level of complexity starting at simple thermal analysis (heat transfer through walls, internal heat sources, internal long wave radiation, etc.) and ending at pollution emission analysis under operation of HVAC systems (demand controlled ventilation, heating and cooling).

This paper introduces results from the first part of the exercise covering simulations carried out by using following 2D tools CHAMPS-BES, DELPHIN5 and DELPHIN6.