Solar cooler

Solar
cooler
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What you need
to know
No electricity required for cooling
The warmer the day, the higher the cooling efficiency
Freon-free, non-toxic operation
Reduce your environmental footprint!
Egyptian frescoes dating back to 2500 BC depict porous containers
with water that served to cool food as well as water itself. Apparently,
the solar cooler technology is very old and people nowadays are just
rediscovering forgotten techniques.
The solar cooler is at your service on summer days, outdoors, when
you need to store your food in a cool place temporarily. It won’t
replace your traditional cooler, but may come in handy in the absence
of electric power. Indeed, it doesn’t consume any electricity at all.
How it works
The solar cooler is an appliance that consists of two porous pots, a layer of wet sand in
between the pots, and a lid covered with wet sand on the top. Since your food loses heat as
the water evaporates, expect best results on hot and dry days. The cooler has to be placed
in a dry and well-ventilated place on direct sunlight. Its efficiency decreases with higher
levels of relative humidity.
Solar
Cooler
Measurements indicate that the cooler works in Central
European climatic conditions as well. On warm and dry
days, the inner temperature drops quickly. With ideal
weather and a well-built cooler, the contents may cool
down to as low as 6 degrees Celsius.
2 ceramic flower pots (fired, unglazed)
1 insulation tape
1 dish for the lid (possibly a flower pot dish)
River sand
Solar
Cooler
Our experience
What you
will need
1
Take river sand and sift it, keeping only grains smaller than the head of a pin.
2
If the pots have holes in the bottom, use insulation tape to caulk them. Alternatively, fill
them with a piece of cork.
How to make it
3
Cover the bottom of the larger pot with a layer of sand so that when you put the other pot
on top, their edges are in the same height. Place the smaller pot on the sand and centre it.
4
Fill the cavity between the two pots with sand up to slightly below the edge. The ditch will
make it easier to pour water in. Take the dish and fill it with more sand (at least to one-third of its
height).
5
Pour water slowly into the sand between the pots. Keep pouring as long as water is being
absorbed. Do the same for the lid.
6
Check your water regularly and add more when the sand is starting to get dry.
Solar
Cooler