How do you deal with air tightness testing buildings over 100 000 sq ft? And what do you do about lift shafts and risers if the building is tested in separate parts? Do you need seal up the lift core? And how do you treat the aera of external facade above the ceiling level?
BRE can test very large buildings for air tightness, with a range of fans designed to provide airflow sufficient to pressurise large buildings. There will be a few buildings that are too large for a single fan. If this is the case, multiple fans can be used.
Re the lift shafts. The building should be air tightness tested as a whole, rather than testing small areas or zones. The lift shafts and service risers are not tested, the doors should provide a barrier agianst air leaking into the risers and shafts.
If the ceiling is not providing an air barrier, then the external facade above ceiling level shouls be air tight.
Source
Building Sustainable Design
