Foodservice Equipment Reports

Full Steam Ahead

Maybe there was a lot of room for improvement. Or perhaps engineers and equipment designers like playing with steam. Whatever the reason, makers have been churning out new and improved steamers for several years now, giving you even more—and better—choices than you already had.

Want to save energy and water costs? Equipment makers have steamers for that. Want more steam, faster? There’s a model or two for that. Want greater production capacity and energy savings? Amazingly enough, manufacturers can help you out there, too. And a couple of companies have hinted they’ll have more tricks up their sleeves by the time you get to the NAFEM Show.

There’s nothing fancy about most steamers, at least on the surface. Typical units have an on/off switch, a timer and an indicator light or two. Most models give you atmospheric steam in one flavor: 212°F, with only an exception or two. So, there’s not much to be done to improve performance or efficiency through fancy computer controls like on a combi oven. But it turns out there are improvements to be had, some through a little digital wizardry in areas other than controls, and some through old-fashioned design and engineering.

Serious Savings

Innovations we’ve seen in the past few years have been concentrated in three main areas: water and energy savings, water quality and reliability, and power—steam power, that is. Back in 2002 when talk about making steamers an Energy Star category got serious, most folks figured it was a no-brainer that boilerless, open-reservoir connectionless steamers would top the list of energy-efficient models.

Energy Star set the specs for steamers up to a 6-pan capacity, with the assumption that’s where the bulk of the market is. What no one expected was that a 10-pan steamer would meet the efficiency criteria. Nor did many people think that units with steam generators would make the cut, but now several boiler-based models do.

Since August 2003, when the Energy Star specs took effect, ever more steamers have become more efficient. Saving water has been the focus for many manufacturers, figuring the less water you have to turn to steam, the less energy you’ll use, too. To that end, several makers have added water-management systems that use sensors in the steamer cavity to measure temperature, pressure or both to determine the proper amount of steam for the food being cooked. When there’s enough steam in the compartment, the unit goes into idle mode, saving energy.

Another water-saving factor has to do with how the steam is handled after it condenses. Condensed steam is too hot to run straight down the drain in a plumbed unit.  You have to bring down its temperature by mixing it with cooler water—a lot of it, which is another expense.

On connectionless steamers, of course, there’s no drain hookup, so you don’t have that problem. That slashes your water usage to about 10% as much as a plumbed steamer. Depending on model, you might be talking 8 gals./day for a connectionless version, as opposed to as much as 30 gals./hour (yes, hour) or more for a traditional, plumbed, boiler-based model.

Makers of both connectionless, boilerless units and plumbed, boiler-based steamers have found other ways to cut water consumption as well. The water-management systems work just as well on plumbed models as on connectionless units. One manufacturer, for example, cites water consumption of about 4 gals./hr. in some of its connectionless, boilerless steamers and about 8 gals./hr. in its new 6- and 10-pan floor-based gas models with steam generators—a far cry from the 30 gals./hr. of older units.

One maker’s connectionless units now have a condensate box where steam cools before draining from the compartment. The design saves water and keeps steam in the cavity longer, saving energy.

Another maker’s new steamer series vents steam up out of the unit into your kitchen’s hood ventilation system instead of down into a drain. The design removes steam more quickly, using less water overall in the process.

A clever idea from yet another manufacturer is a staged water fill. In most systems on the market, the water in the steam generating tank drops to a low level before the tank automatically refills. That process takes time, from refill to boil to steam. But these new staged-fill units are different. After a rapid-fill start up, these staged units use a sensor high up in the tank to trigger a slow refill to top off the tank as needed. Sort of a bottomless-cup effect. With no dramatic fluctuation in the heating cycle (like a big inflow of cold water), you have constant steam with no recovery time—and less water use.

Power To Burn

How significant are all these improvements? Manufacturers are claiming 30%  to 50% savings in energy costs on Energy Star models versus traditional counterparts. The Environmental Protection Agency figures you’ll save about $500 a year, but in some areas of the country, your savings can be substantially more. With utilities offering rebates on energy-efficient equipment, payback on an Energy Star qualified steamer can be as little as one year.

Gas-fired steamers, in particular, have gotten more efficient in recent years. A couple of manufacturers now use redesigned high-performance burners in their steamers. One uses ceramic burners to improve efficiency.

Another maker has added super-efficient forced-air combustion burners to one of its model lines, and it runs heat-exchange tubes through the water in the steam generating tank. The combination of efficient burners and better heat transfer adds up to greater energy efficiency.

Yet a third steamer maker says its new burner is not only more efficient, but burns more quietly, a welcome feature in noisy kitchens.

Along with the efficiency comes performance. Several models offer faster cooking and recovery times. The gas model with the staged water fill referenced above has a 125,000-Btu burner and produces 235°F super-heated steam, speeding cooking time and increasing throughput.

Convection steamers, too, provide more cooking power by circulating steam throughout the compartment. A couple of manufacturers have redesigned their steamers to vent steam into the compartment through directional ports. The ports are restricted, slightly increasing pressure and the velocity of the steam as it enters the cavity, circulating the steam in the compartment without a fan or any moving parts.

A Matter Of Scale

While steam is the most effective way to transfer heat into food products, hot water is no friend to equipment. A big issue with boiler-based steamers is their need for regular de-liming to prevent scale build-up. Boilerless units virtually eliminate that problem by producing steam right in the cooking compartment, meaning all you have to do is wipe out the interior daily. But even boilerless units can succumb to scale if you don’t maintain them properly.

Several manufacturers have made little design changes to improve reliability when it comes to water and scale issues. One area in which scale (and food soil) accumulates is the drain, and a few makers have addressed the problem in different ways.

One took the approach of sloping the cavity floor on its units toward the drain. It also redesigned the drain itself to create a Venturi effect as the water leaves the compartment, essentially sucking the water out. The design makes it easier to flush the unit after cleaning at the end of a shift.

A couple of other steamer makers attacked the problem at the drain valve. Typically, steamer valve drains operate with a solenoid switch. But if scale or sediment sticks in the drain, the valve can stick or fail to close tightly and may ultimately cause the switch to fail. New models have a mechanical ball valve operated by a micro switch. The heavy ball can easily crunch any sediment or scale, preventing the valve from sticking.

Another way manufacturers are improving reliability is by addressing the water/scale issue before it becomes a problem. One new steamer series features a built-in water filtration system, taking the guesswork out of where to place the filters and what kind to use.

At least one manufacturer wants you to avoid problems of scale altogether. Most water filters designed to control scale use some form of polyphosphate to “coat” calcium and magnesium particles and prevent them from sticking to surfaces. But a citric acid product called Citryne lowers water pH and prevents scale from forming. It even dissolves existing scale and puts it back into suspension.

Water savings, energy savings, power and greater reliability—what more could you want from a piece of equipment? Today’s new crop of steamers can give you pretty much everything you’re looking for, even in the right combination if you look carefully.

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