Le 31 juillet 2018 à 01:52:51 Peruvian a écrit : The practice of putting streamers on air vents and fans is quite old, dating back to the 1800's. Streamers serve several purposes. First, motion of the streamers indicates air flow. This can be helpful when going up to the vent or fan is inconvenient. Imagine a room with 20 vents - a quick visual check shows the flow.
Second, the angle of the streamers is an indication of flow velocity. If the streamers are uniform, air flow from different fans/vents can be somewhat balanced against each other. The more horizontal the streamer, the faster the flow.
Finally, on an oscillating fan, streamers show the direction in which the fan is pointing. It can also be visually appealing when the streamers are different colors.
Sachant que le dernier paragraphe est pas plus logique que ton explication. J'en déduit qu'il n'y a donc aucune bonne raison à part le conformisme habituel du bonobo moyen.
Sinon pour le reste ça se tiens
Ok Jean-Complotiste je te donne l'explication historique à ta question et tu m'insultes pour cacher ta PLS