Cold-plunge tub chills water – and users – without ice or refrigerants

Although hot tubs may get all the glory, cold-plunge tubs are the ones that really help reduce muscle inflammation and soreness after exercise. The Snowcap tub makes that process more doable than ever, by chilling water without using any ice or refrigerants.

Currently the subject of an Indiegogo campaign, the Snowcap is made by Australian startup Clearwater Ice Baths.

The inflatable one-person tub itself is composed of watertight drop stitch fabric, weighs 8 to 10 kg (18 to 22 lb) when empty, and can hold 300 to 320 liters (79 to 85 gal) of water. Its 18-kg (40-lb) lid incorporates a fold-down 20-micron water filtration unit, which draws the water up through an integrated thermoelectric cooler.

Putting it very simply, a thermoelectric cooler (aka Peltier cooler) uses an electrical current to draw heat from one side of itself to the other.

In this particular case, the side from which the heat is drawn is in the water, whereas the side that's releasing the heat is exposed to the air. This arrangement allows the device to cool water which is being circulated through it, without utilizing any moving parts, refrigerants or ice.

According to its designers, the Snowcap takes about eight hours to cool water from an ambient temperature of 25 ºC (77 ºF) down to a chilled temperature of 1.5 ºC (35 ºF) – the system uses about $1.10 worth of electricity to do so. The lid simply gets plugged into a regular electrical outlet.