did-you-know: Ancient Persian engineers made their own freezers that kept ice cold - even during des
did-you-know: Ancient Persian engineers made their own freezers that kept ice cold - even during desert summers. By 400 BCE, they had perfected the ‘yakhchal,’ which are made of thick, heat-resistant materials. They had vents to funnel breezes to an underground storage area and push warm air out the top, and ice could be brought in during winter to use for making chilled treats in the summer. (Source, Source 2) -- source link