To indicate the Jet Stream we will use particles.
The particle image is the same for Vertical & Horizontal.
We just change the angle.
The image can be found in the Other folder --> Dust Particle.png
Vertical Particle Settings
Place it just above the Vertical Fan
Horizontal Particle Settings
Place it just above the Horizontal Fan
Adjust the settings as shown
X randomiser value is 0 for horizontal fan
Y randomiser is 65 for horizontal fan