Car Park & Jet-Fan Ventilation
A clear guide to ventilating enclosed car parks — why it is needed, how traditional ducted systems compare with modern ductless jet-fan (impulse) systems, and how the same fans provide smoke control under UAE fire requirements.
Enclosed and underground car parks accumulate vehicle exhaust — carbon monoxide and, from diesels, nitrogen oxides and soot — which must be diluted and removed to keep the space safe to breathe. A car park ventilation system continuously, or on demand, exchanges the air to hold pollutant levels well below harmful limits.
In most UAE basements the same system has a second, life-safety role: clearing smoke during a fire so occupants can escape and firefighters can operate. Because of this dual duty, car park ventilation is both a mechanical comfort/health system and part of the building fire strategy, and it must satisfy the requirements of Abu Dhabi Civil Defence.
How it works
Why ventilation is needed. Idling and moving vehicles release carbon monoxide (CO), an odourless toxic gas. Ventilation dilutes CO and other pollutants with outdoor air and exhausts the contaminated air, keeping concentrations within safe limits. Systems are usually demand-controlled, ramping up only when sensors detect rising pollutant levels, which saves energy.
Traditional ducted systems. The classic approach uses supply and extract fans connected to networks of ductwork that distribute and collect air across the car park. Ducts are bulky, reduce headroom, and add cost, but the method is well understood and gives defined airflow at each grille.
Ductless jet-fan (impulse) systems. A modern alternative removes most of the ductwork. Small induction (jet) fans are mounted under the slab and aimed to push air in a controlled direction. Fresh air enters through supply shafts, the jet fans sweep it across the space toward extract points, and main extract fans discharge it outside. This frees up headroom, simplifies the slab, and allows flexible airflow paths.
Control and CO monitoring. Carbon monoxide (and sometimes NO2) sensors distributed through the car park feed a control panel. When levels rise, the system increases fan speed or starts more fans; when the air is clean, it runs at minimum or stops. Variable-speed drives make this modulation efficient and quiet.
Dual-purpose smoke clearance. On a fire signal the same jet-fan system switches to a smoke-control mode: selected fans run at full speed to drive smoke toward the extract shafts and create clear paths for escape and firefighting. This requires fans, cabling and controls rated for high-temperature operation and integrated with the fire alarm — a defining requirement for car park ventilation in the UAE.
Main types
In the UAE
- In the UAE, enclosed car park ventilation typically doubles as a smoke-clearance system and must comply with the UAE Fire and Life Safety Code of Practice and Abu Dhabi Civil Defence requirements, including smoke-rated fans and fire-survival cabling.
- Demand control based on CO (and where relevant NO2) sensing limits running hours and supports Estidama energy objectives while maintaining safe air quality.
- Jet-fan systems are popular in Abu Dhabi basements because they save headroom and ductwork, but their fire-mode airflow design must be validated and the controls fully integrated with the building fire alarm.
How GPR applies this
GPR designs, installs and commissions car park ventilation across Abu Dhabi, including modern ductless jet-fan systems and traditional ducted layouts, with CO/NO2 demand control to minimise energy. We coordinate the dual ventilation and smoke-clearance duties with the fire strategy, install smoke-rated fans and fire-survival cabling, and integrate the controls with the fire alarm so the system satisfies Civil Defence and keeps basements safe in both everyday and emergency conditions.
Frequently asked questions
Why do car parks need mechanical ventilation?
To dilute and remove carbon monoxide and other vehicle exhaust pollutants in enclosed spaces, keeping the air safe to breathe.
What is a jet-fan (impulse) ventilation system?
A ductless system using small induction fans mounted under the slab to push air from fresh-air supply points across the space to extract shafts, saving ductwork and headroom.
How does the system know when to run?
Carbon monoxide (and sometimes NO2) sensors monitor air quality and signal the controller to increase or decrease fan operation, so it runs only as much as needed.
Can car park fans also handle smoke during a fire?
Yes — in the UAE these systems are usually dual-purpose, switching to a smoke-clearance mode on a fire signal, which requires smoke-rated fans and fire-survival wiring.
Are jet-fan systems better than ducted systems?
They save headroom, cost and ductwork and allow flexible airflow, but the airflow and fire-mode performance must be carefully designed and validated for each car park.