Shafts and Plenums
- Masonry or Hebel shafts or plenums used as a return air/exhaust plenum or stair pressurisation must be:
- Bagged on the internal face to minimise air leakage
- Checked for structural integrity.
- Other non-duct shafts (i.e. Speedpanel) used as a return air/exhaust, irrespective of all other requirement, must be sealed on the internal face to minimise air leakage.
