Characterisation of garage-air recirculation in a new building using a tracer.

Air recirculation in the new office and laboratory building of the Norwegian Institute for AirResearch was discovered and characterised from a leaking sulphur hexafluoride cylinderstored in the garage. The garage/staging area was located at the far end of the right wing ofthe three-storey building, and was used for loading/unloading of equipment and for storage ofequipment and compressed gas cylinders. Sulphur hexafluoride tracer was detected in thecorridor on the ground floor right wing leading to the central reception area. Tracer was alsodetected in stairwells and in corridors and offices on the third floor of the building, all areaswhere automobile exhaust and gasoline smells had been occasionally reported. A routinedeliberate tracer release in possible problem areas is suggested as a tool to help in evaluatingventilation system performance before a building is put into service.