Vaccine refrigerator runs on evaporation cycles.

Vaccine refrigerator runs on evaporation cycles. Coolar’s solar-powered refrigerators could improve the way vaccines are stored in developing countries.Julia Römer's refrigerators produce cold from heat. Many medicines - from asthma sprays to insulin to vaccines - must be cooled until moments before they're used. But in large parts of the world, electricity is not readily available In a conventional refrigerator, low temperatures are caused by the evaporation of a coolant. In Römer's solar-powered version, the evaporating liquid is water. Her system uses silica gel to attract water after evaporation and create a cycle: a solar panel generates heat that causes the gel to dry, then the water evaporates and is returned to circulation. The solar chiller needs almost no maintenance and is easy to dispose of since it doesn't contain any polluting substances.more