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Primitive ideas of ancient peoples by today’s means were not that primitive after all. For instance these ideas allowed for desert people to have ice during summer when there was no ice for thousands of kilometers around. Yakhchal is one such idea.
Although it looks like a new invention idea of a solar-powered refrigerator is relatively old and pretty simple - to use heat of the sun instead of the compressor in the refrigerator to liquefy the refrigerant. Read more about solar-powered refrigerators.
Fridges and their stronger and colder cousins - freezers are today required equipment in every home. But it was not always like that. They ancestors were much simpler and not too practical. Find out more about fridges history.
People needed to keep perishable food on low temperatures before the refrigerator appeared as well as today. As a source of cold in the wormer months they used ice from lakes and rivers stored in ice houses during the winter. Read more about history of ice houses.