Botijo Water Cooling
The earthen walls of the botijo absorb part of the water contained
in the jug. The water reaches the surface, where it slowly
Water evaporation requires energy. Part of this energy is extracted
from the water jug, resulting in the cooling of the water within.
The amount of cooling depends on many factors, such as the shape of
the botijo, the material of which it is made, the amount of water
within, the outside temperature, the humidity, etc.
Under good conditions, a cooling of about 10 degrees Celsius is
Similar cooling methods
can observe the same water cooling effect of a botijo on a canteen with lined
cover. If you submerge the canteen in water so that the cover absorbs the water,
and then leave the canteen outdoors until the cover dries up, the water inside
the canteen will have cooled.
You can also observe this effect by placing a regular water bottle inside a tick
sock. Soak the sock and place the bottle outside until the sock is dry. The
water in the bottle will have cooled.
In the year 2000 a Nigerian teacher was awarded the Rolex Award for Enterprise for
his utilization of the water evaporation cooling system to implement a food
preservation system for dry climates.
His implementation consists of two earthenware pots of different sizes, placed
one inside the other. The space between the pots is filled with wet sand, and
food is placed in the inner pot. The evaporation of the water in the sand
between the pots cools the inner pot, using the same effect used in a botijo. By
keeping the sand moist, the food in the inner pot is kept cool.
You can read a full description of this cooling device