Two-directional air movements in stairwells.

The predominant route for air movements between the floors of two-storey dwellings is via the stairwell. Such air movements are of significance in the assessment of building performance: for instance, it is possible that moisture could be transferred from ground floor areas to rooms on the first floor, resulting in an increase in condensation risk in such rooms. Several domestic heating schemes have been designed such that heating appliances are provided on the ground floor only; the upper floor relying on convective airflows for heating. If the ground floor to first floor airflow induce by such a system is too small, then the upstairs room will not attain the desired temperature, which in turn could lead to condensation problems, quite apart from the issue of occupant discomfort. This paper summarises two case studies of air movement measurements performed by means of the UMIST PCS system, and analyses the data in terms of moisture migration and heat transfer.