The Pok Oi Hospital isolation room ventilation system was found with a “red” light on 27 May 2020, that ventilation system maintains negative pressure inside the isolation room to reduce the risk of airborne transmission within the hospital.
An investigation found that the ventilation stopped operating because a contractor, working on the hospital roof, accidentally triggered the Emergency Stop (e-stop) button at sometime during the afternoon, but obviously failed to notice that the ventilation system was shut down.
The report says the fault was discovered by the red light in the isolation room, which implies the HVAC system did not have any audible fault alarm in the occupied area, or at the roof level.
If you have ever wondered about how far ITC has infiltrated our lives, in the report, it states the HVAC system was rebooted!
Other design considerations, typically code requires HVAC systems >1000 l/sec to be interlocked with the automatic fire alarm system, triggering the fire alarm automatically closes ALL the HVAC systems, for hospital isolation room that risks covid19 contamination of the whole ward.