The JETFAN System by Howden American Fan Company is an alternative option for underground parking garage ventilation. It overcomes the limitations of ductwork-based ventilation systems and is better able to meet project-specific requirements as well as local and national building codes and regulations regarding ventilation rates, pollution control, and emergency ventilation requirements.
The JETFAN System replaces traditional ducted garage ventilation distribution with a number of small ceiling-mounted fans. It pulls air into the fan inlet (i.e., a grille/louver) and discharges at a high level towards the exhaust locations (i.e., a duct/louver/fan). This moves fresh air in and polluted air out effectively and efficiently. A typical system includes the main exhaust fans, supply fans (if required), JETFAN units, detection system for pollution, CFD analysis, control panels, and associated wiring. The system can be designed around the specific requirements of each facility.
JETFAN System fans are controlled to detect pollution and activate only as needed to meet required pollution thresholds. They can be equipped with optional reversible flow capability for emergency smoke ventilation and access for fire personnel. The system can also be zoned, so all fans do not have to operate at the same time.
The main supply/exhaust fans are designed and independently certified by UL for normal operating temperatures or high temperatures up to 500°F for four hours. Supply fans are sometimes used to provide fresh air into the parking facility, plus provide air to ramps and inlet grilles/louvers.
The JETFAN units are custom designed for parking garage applications in sizes from approximately 12.4″ to 17.72″. They incorporate a temperature rated and certified axial flow fan, complete with integral inlet and outlet silencers. Low loss guards, a mounting assembly, and cylindrical silencers are standard. Units are made for a variety of temperature/time ratings and motor options.
JETFAN units are positioned to control the distribution of the air within the structure. They can be used to create a flow of air at both high and low levels within the facility, effectively using the same air twice. Computerized Fluid Dynamics (CFD) analysis (internal link) is used to plan and optimize the complete ventilation system.
The JETFAN System lowers the required parking garage height by about 4′, reducing excavation and cement costs and lowering overall construction costs. Reduced system resistance allows the system to work at lower speeds, which reduces power absorption and overall operating costs. It also lowers noise levels.