Cooling by Evaporation Concept

Demonstrations in Cooling by Evaporation

Cryophorus: a glass apparatus with two spherical bulbs connected by a long glass tube, lying on a tabletop in front of a chalkboard
Safety

Cryophorus

Water freezes inside a partially evacuated glass bulb solely through evaporative cooling -- the dry-ice-cooled second bulb acts as a cold trap that continuously removes water vapor, driving rapid evaporation …
Three-panel photo: top shows overhead projector on movable bench with vacuum pump below; bottom-left shows vacuum chamber apparatus with magnifying lens on projector stage; bottom-right shows close-up of concave lens, cover glass, and eyedropper
Safety

Freezing by Boiling

Water boils and then freezes under reduced pressure in a projected vacuum chamber. Demonstrates that boiling point is pressure-dependent and that rapid evaporation removes enough latent heat to freeze the …
Drinking bird mid-cycle, captured with motion blur showing its rocking oscillation, on a clear acrylic tray with an empty glass beaker beside it
Safety

Drinking Bird

Evaporative cooling of the bird's wet head lowers the vapor pressure of the ether inside, drawing liquid up into the head and shifting the center of mass until the bird …