This I cut from the Kayfun manual, it applies to Oddy/Ithaka and their clone as well.
Another example: Take a straw, deep half of it vertically in the water, close the top opening of the straw with
your finger and pull it out of the water. Low air pressure at the top of the straw will hold water in it, but as soon
as you release your finger the sealing of the air bubble is broken, pressure equalizes and water discharges.
Kayfun works on the same principle.
When the user initiates the inhalation process, negative pressure is formed inside the evaporation chamber
which draws a small amount of e-liquid through the grooves (1i) into the evaporation chamber where it gets
absorbed by the wick located directly above these grooves. Low pressure is produced in the tank due to the
transfer of e-liquid to the evaporation chamber. When the user has completed the inhalation process, the
pressure in both the evaporation chamber and the tank are normalized due to the air being passed back into the
tank through the ducts.
During the inhalation process, the evaporation chamber receives liquid from the tank through the grooves (1i)
and after the inhalation the tank receives air from the evaporation chamber. This process can be visually
observed as air bubbles rising from the grooves in the tank (provided the transparent ring is being used).
E-liquid that entered the evaporation chamber during the inhalation is absorbed by the wick. The wick is
saturated and distributes e-liquid over the coil. The coil heats up and "atomizes" liquid. At the next inhalation
this cycle is repeated until there is no more liquid in the tank or the battery is depleted.