Before the refrigerator
People kept food cool in cellars and in iceboxes, using ice that was cut from rivers and lakes in winter and stored in straw. Meat was smoked and salted, and vegetables were fermented.
Einstein invents a fridge
In 1930 Albert Einstein and his former student Leo Szilárd patented a refrigerator with no moving parts. They were inspired by the case of a family poisoned by toxic gas leaking from their fridge. It never went into mass production.
Freons and the ozone layer
CFC refrigerants (freons) were safe for people but destroyed the ozone layer. The Montreal Protocol of 1987 banned them, and the ozone hole is slowly shrinking. It is one of the most successful international agreements in history.
Calex
Calex refrigerators and freezers were made in Zlaté Moravce, and in the past many Slovak households had one.