Advantages of Dry Hot Wells
If you're drilling for oil or water, the last thing you want is a dry well. Until recently, the same was true for foodservice operators; a dry well on your steam table meant the possibility of food held at improper temperatures, excessive lime and scale buildup, scorched equipment or even a burned-out heating element from getting to hot.
Steam tables can have other challenges too. While heat transfer from steam surrounding a food pan is even and efficient, the cost of both water and energy to heat it is high. The hot water and steam can burn employees as they change out food pans, posing a safety risk. As the water boils, it evaporates and has to be replaced, requiring additional labor. And some steam tables can be messy and difficult to clean out at the end of the night.
Manufacturers have made improvements to steam tables over the years with features such as autofill and drains. But auto-fill requires plumbing connections, which are expensive to install. And in many jurisdictions, if you use models with drains, you’re required to have floor drains beneath the equipment.
Certain steam well models can operate wet or dry, but they’re designed primarily to be used with water. However, many manufacturers now offer hot food wells specifically designed to operate without water. Many such wells are drop-in models while at least one manufacturer builds countertop wells and wells that fit over equipment that cooks, holds or retherms.
Why Go Waterless?
Dry wells offer plenty of benefits when compared with steam wells. Here are a few:
Installation. Dry wells require no plumbing or drains, making them ideal for remodels where those utilities aren’t available, and saving installation costs on new construction, too. One manufacturer estimates typical savings on installation of between $1,500 and $2,500.
Food safety. Dry wells maintain constant, even heat. When steam tables are refilled with water, recovery time to bring the water temperature up to near boiling can put food in danger.
Flexibility. Most makers offer line-ups of modular drop-in units ranging in size and shape to offer flexibility in both design and capacity. Because many dry heated wells are insulated, drop-ins can be used with a variety of countertop materials. And because there’s no risk of water leakage, those counters and cabinets are less likely to be damaged. Waterless wells can even be used on mobile buffet/food stations as long as electrical service is available, giving you the option of changing a service area layout for different dayparts or meals.
Labor savings and safety. Eliminating water means employees don’t have to refill wells during their shifts or drain wet wells every day. And the absence of steam makes it far less likely that employees can get burned when refreshing food pans or cleaning the unit at the end of the day or shift.
Less maintenance. Dry heated wells don’t need to be delimed, and endure less wear and tear than steam tables do from poor water quality and/or scorching from unintentionally letting them run dry.
What's Your Heat Type?
Manufacturers use several different ways to transfer heat from a dry hot well to a food pan. All do the job about as well as steam. They all have minor pros and cons, however, which you should weigh carefully to decide which fits your operation best.
Radiant. Waterless wells with radiant heat designs have heating elements either in the base of the unit under the warming pan, exposed under the food pan, or wrapped in the walls and base of the warming pan itself. Disadvantages of a heating element located only below the food pan is that it can get very hot, so food can get scorched on the bottom or dried out when operated without water. The heating elements in the wrap-around design surround food pans with radiant heat (much the way steam does) so it operates at less extreme temperatures than the bottom-mount design. Regardless, these units should be insulated to retain heat.
Convection. These units have a heating element and a fan in the bottom of the warming pan that circulates hot air around the food pan. They provide even heat, but must be insulated, and do add a small amount of noise to the ambient environment. While specifically designed for waterless operation only, one maker added drains to its units in the event an employee accidentally spills or pours something into the well.
Induction. Electromagnetic coils in the base react with the special metal in certain food pans, heating them and in turn the food they contain. A big plus is that the only heat comes from the food pan itself, so these units don’t need to be insulated and can be mounted in virtually any countertop material. Heat also can be precisely controlled, and units typically require less wattage than designs with heating elements. They may be more expensive up front, but energy savings will likely add up in the long run. They require special pans, however.
Conduction. One maker’s design circulates heated polypropylene glycol through the walls and bottom of the warming pan, which comes into direct contact with the food pan, conducting heat into the food.
What to Look For
When ready to specify waterless hot wells, take note of the following features:
Construction. Wells should be constructed of deepdrawn, heavy-gauge stainless. Look for coved corners and clean welds. You can buy individual wells, open wells or ganged/modular wells in a variety of sizes and configurations. Temperature control is more precise on individual and modular wells. Most units will accommodate both 2 1/2-in.D and 4-in.D hotel pans, and many will even accept 6-in.D pans.
Controls. Temperature controls may be electromechanical or digital, and they can be infinite or thermostatic. Infinite controls let you adjust the temperature for different foods (usually on a dial from one to 10) but you may have to experiment to find the right setting. Thermostatic controls maintain a specific temperature in degrees that you set. Having controls for each individual well, whether single or modular, will give you the most flexibility.
Electrical service. Match the specifications of the model you purchase with the electrical service you have available. Most makers offer models in 208V and/or 240V service, but you’ll need the right amperage circuits to operate these wells. Also, some are plug-and-play, but many models must be hard-wired so will cost more to install. Finally, pay attention to wattage, as models that use fewer watts per well typically save you money, but perform as well as higher energy users.
Clearance. Make sure you have the recommended amount of clearance around drop-in hot wells, not only to protect components such as controls from heat the wells produce, but also whatever countertop materials you use. Some hot wells may require more clearance than others, depending on countertop materials and heating method. Induction units typically need very little clearance.
Certification. Be sure the units are third-party certified. If NSF, they should meet NSF4 for food safety holding temperatures as well as NSF7 for cleanability. If UL, units also should meet UL Sanitary certification.