Hoshizaki Corporation has developed its first ice slurry refrigerator, the RT-90SNJ-IS, using natural refrigerant R-600a (isobutane). The commercial unit cools bottled drinks to a supercooled state, allowing users to produce a flowable mixture of fine ice crystals and liquid by tapping the container. Sales through Hoshizaki’s sales companies will begin on October 29, 2026.
The refrigerator uses supercooling technology adapted from Hoshizaki’s pharmaceutical refrigeration systems. To prevent ice crystals from forming during cooling, the cabinet temperature must remain within ±1°C (±1.8°F) of the preset temperature. According to the company, temperature variation inside the cabinet is one-third or less than that of its standard refrigerators.
The RT-90SNJ-IS measures 900 × 600 × 800 mm (approximately 35.4 × 23.6 × 31.5 inches) and has an internal volume of 151 liters (approximately 5.3 cu ft). It can cool 60 bottles of 500 ml (16.9 US fl oz) in approximately 14 hours or 40 bottles in approximately 12 hours. Actual cooling times depend on ambient temperature, bottle quantity and other conditions.
The unit features an elapsed-time display, automatic defrosting with wastewater collection in a tray, and a switchable operating mode for use as a conventional refrigerator. It is designed for indoor ambient temperatures from 5°C to 40°C (41°F to 104°F). The R-600a refrigerant has zero ozone depletion potential and a global warming potential below 1, according to the UNEP assessment cited by Hoshizaki.
Hoshizaki developed the refrigerator for applications involving heatstroke prevention, including factories, construction sites, schools and sporting events. The company states that consuming ice slurry before work can help limit increases in core body temperature. The launch follows Japan’s introduction of mandatory workplace heatstroke prevention measures in June 2025. The refrigerator will be offered at an open price.
