In Australia once a building is built, there is little requirement for retrospective upgrading (except when major work mandates upgrade using the 50% refurbishment within a 3-year period rule, whereupon it is required to update to those code requirements or equivalent at that time – though many do whatever is possible to avoid this and most goes unnoticed).
We have observed that many hi-rise building with HVAC installations pre-dating AS1682.1&2-1990 are without appropriate breakaway on the ductwork.
Why is the breakaway requirement so important?
- > Because if there is a fire, there is every likelyhood that the duct shall collapse and this shall result in the duct without breakaway pulling the fire damper from the wall as well as that action leading to partial wall collapse.
- > If there was breakaway, the duct would collapse but the fire damper would be retained within the firewall and provide the required protection.
It is my personal belief that whenever there is the opportunity (vacant possession, refurbishment, etc.), that every opportunity is made to update these systems in that accessible part of older buildings to reflect current performance requirements (or deemed equivalent).It should also be recognised that those maintaining and assessing these systems are referencing them back to the performance standards associated with their installation (operational check) and this means that the assessment reporting fails to identify non-conformance to what is current “minimum best practice“.
It has also been observed that inappropriate practices by other trades are not being reported by service technicians/ maintainers and this degrades the performance from that of the original installation (cables and pipes adjacent to duct penetrations of firewalls, etc).
It needs to be known that the assessors are actually obliged to endorse performance based entirely upon the standard of installation and such a process while conforming to the legislative requirements (and covering the assessor from liability), still leave a residual risk until that building is fully upgraded.
The building owner/building controller, remain as the responsible entity for the safety of those in occupation and should give consideration to management of those risks as well as any risks introduced by those occupants.
Building owners require that any new works reflect current requirements but are under no obligation to elevate the base building.