An inkjet nozzle device configured for venting a gas bubble during droplet ejection. The inkjet nozzle device includes: a firing chamber for containing ink, the firing chamber having a floor and a roof defining an elongate nozzle aperture having a perimeter; and an elongate heater element bonded to the floor of the firing chamber, the heater element and nozzle aperture having aligned longitudinal axes. The device is configured to satisfy the relationships A=swept volume/area of heater element=8 to 14 microns; and B=firing chamber volume/swept volume=2 to 6. The swept volume is defined as the volume of a shape defined by a projection from the perimeter of the nozzle aperture to the floor of the firing chamber, and includes a volume contained within the nozzle aperture.