Commercial steam cookers (or compartment steamers) are used in commercial kitchens and can be powered by either electricity or gas.
There are currently no national standards for commercial steam cookers. In May 2018, Vermont adopted state standards for commercial steam cookers based on ENERGY STAR Version 1.2, which has been in effect since 2003. According to EPA, commercial steam cookers meeting the ENERGY STAR specification offer shorter cook times, higher production rates, and reduced heat loss. In addition to saving energy, commercial steam cookers meeting the ENERGY STAR specification consume about 90% less water than standard models. A traditional steam cooker uses on average about 175,000 gallons of water per year.
While traditional steam cooker designs incorporate a separate boiler or steam generator to produce steam and require a continuous stream of water for cooling, almost all ENERGY STAR–qualified steam cookers use “boilerless” or “connectionless” designs, which do not require cooling water. In 2015, 53% of total shipments of commercial steam cookers were ENERGY STAR qualified.