A car park ventilation system has two very different jobs. Day to day, it removes vehicle exhaust, mainly carbon monoxide (CO). In a fire, it must clear smoke so people can escape and firefighters can get in. A system that looks fine day to day can fail precisely in the second scenario.
System components
- CO sensors, sometimes with NO₂ sensors, that start the fans according to gas concentration.
- Jet fans hung from the ceiling that push air towards the extraction points, or a ducted system with extract grilles.
- Main extract fans that remove air from the car park, plus fresh-air openings or supply fans.
- A controller and electrical panel that run the system from the sensors, on a schedule, and in an emergency on a signal from the fire detection system.
Source of requirements
Car park ventilation is defined by the building permit, the approved design and the fire authority's requirements. The number of fans, airflow, fire-mode operation and testing intervals all follow from that design. The binding requirements for each building are in its documentation and in the authority's instructions.
Scope of routine maintenance
- Calibration and function checks of the CO sensors, to the manufacturer's instructions.
- Running every fan, including direction of rotation, vibration and noise.
- Condition of bearings, belts (on belt-driven fans) and motors.
- A smoke-mode test: triggering from the fire detection system and confirming every fan switches to the correct emergency mode.
- Emergency power supply, where the design calls for it.
- Cleaning extract grilles and dampers.
Fault indicators
- A smell of exhaust fumes in the car park, especially at peak times.
- Fans that run all the time, or never.
- Recurring sensor alarms.
- Unusual noise or vibration from the jet fans.
Read about buildings and car parks or book a site survey.