COMIS (Conjunction of Multizone Infiltration Specialists) is a multizone airflow simulation program. COMIS 3.2 uses the Simulation Studio, the powerful and convenient simulation environment which is also used by TRNSYS 16. The two programs can be coupled via this environment, thus allowing for coupled thermal and air flow studies. COMIS 3.2 has been developed in a collaboration between EMPA and CSTB and is maintained by these two organizations. It is based on the result of the International Energy Agencies (IEA) Annex 23. Many modules are embedded into COMIS, from air flow components such as cracks, test data components, windows, doors, vertical apertures (2-way flow), ducts and duct fittings, fans, flow controllers to pollutant sources and occupants, plus the possibility of defining schedules attached to most of the components (e.g. closing and opening of windows in relation to inhabitant behavior). Termostatic flow devices (flow resistance depending on the air flow temperature) can also be modelled. All these modules allow for various applications such as sizing of mechanical ventilation systems, effects of retrofitting measures on ventilation efficiency of buildings, transport of contaminants (between zones, but also from outside), ventilation effectiveness, pollutant removal efficiency, age of air, smoke propagation, assessment of ventilation heat losses, passive cooling, assessment of heat transport between zones.