Food Steamers Introduction

There are two types of food steamers used by the food industry to heat food in large quantities.  The traditional design uses steam trays connected to a central boiler.  Newer technology uses individual heating systems to create the steam on each set of steam trays.  The newer technology offers significant advantages in both energy and water efficiency.

The boiler-based steamers utilize a boiler to inject (through pipes) steam into the heating compartment containing the food trays. Steam that does not condense on the food product escapes as a mixture of steam and hot condensate through a drain at the bottom of the set of steam trays. Not only is water wasted in the rejected steam, but also a substantial amount of additional water is required to condense this steam and cool the condensate water to an acceptable temperature before it enters the sewer system (local codes usually require water be below 140F (60 C)  (before entering the sewer system).


In recent years, the food service manufacturers have developed more efficient boilerless compartment steamers, often called connectionless steamers (though some are connected to water supplies).  These new-generation steamers consist of a simple compartment with enough room below the bottom rack for a water reservoir. Steam, generated from the boiling water, rises by natural convection to condense on the food items above, thus transferring the heat from the steam to the food.   A small amount of steam is vented through a port at the top of the compartment while the steam that condenses on the food product or cavity walls simply returns to the reservoir below to be steamed again. This design does not require a condensate drain or accompanying condensate-cooling water. There is no periodic de-scaling (de-liming) of a boiler required.   

The water savings from this new technology can be dramatic.  Efficient connectionless steamers use less than 10% of the water when compared to boiler-based steamers.  Each steamer can save more than 50 gallons per hour (189.2 L) of operation.  This can save more than 500 gallons per day (1.8 m3) for a typical restaurant.  Be aware, not all connectionless steamers are as water efficient.

SPECIAL NOTE OF CAUTION TO WATER PROVIDERS: Some manufacturers have adopted terms like "boilerless" or "connectionless" as a marketing tool without regard for the water efficiency of the equipment. As such, not all food steamers currently labeled as "connectionless" or "boilerless" are, in fact, water-efficient. If your water agency or municipality is considering implementing an incentive program for steamers, be sure to consult with the Food Service Technology Center (David Zabrowski at: OR 925-866-5614) before defining or "listing" the equipment to be included.

Metropolitan Water District of Southern California maintains a list of water efficient food steamers.  The list is updated periodically, and may not contain all makes and models of water efficient steamers.

Additional information can be found at our Commercial Food Service Introduction page.