Commercial Refrigeration Control Options

Dial knobs and rocker switches have long been the norm in refrigeration controls, but as technology advances, it's finding its way into commercial refrigeration equipment. With many manufacturers offering more than one control type, it is beneficial for operators to know which would work best in their kitchen. Below, we'll take a look at each control type's benefits and drawbacks to help you make the best decision on your next commercial refrigeration purchase.

Thermostat Differences

Before we get into the actual knobs and buttons you'll use, you need to know that the external controls impact which parts are used inside the refrigeration unit, as well. A model with mechanical controls, also called electromechanical controls, uses a constant cut-in thermostat, which is placed on the evaporator coils and extrapolates the internal cabinet temperature from the coil temperature. These thermostats have upper and lower limits. The lower limit is the temperature you set, while the upper limit is high enough to allow the coils to defrost during each cycle. For example, you might set your refrigerator to 35 degrees Fahrenheit, which would be the unit's lower limit. The compressor would run until the cabinet's internal temperature reaches 35 degrees, then shut off the cooling system until the evaporator hit its upper limit, which might be around 42 degrees Fahrenheit. The upper limit is warm enough to allow any frost or ice to melt off the evaporator coils, without letting the temperature in the cabinet dip into unsafe territory.

An electronic control can use a thermostat placed in the evaporator coils or the cabinet, and some have one in both. These thermostats hold the internal temperature within 2 to 3 degrees of the set mark. Since the evaporator doesn't defrost with each cycle of the compressor, defrost cycles must be handled separately and can either be time-initiated and -terminated or temperature based. The latter of those necessitates a separate thermostat solely for the defrost cycle. Some units with electronic controls also use adaptive defrost, which monitors the system and runs a defrost cycle only when it is actually needed, cutting power demand.

Mechanical Refrigeration Controls

Mechanical refrigeration controls consist of knobs, buttons, and switches, all of which must be physically manipulated to change or activate settings. Buttons and switches either complete or interrupt a circuit to turn on an interior light or start a defrost cycle, while knobs generally use pressure or voltage to alter the target interior temperature or defrost time intervals. These controls have been used in commercial refrigeration for decades, and that familiarity leads many operators to prefer them.

Pros:

  • Because they cost less to manufacture and are simpler to install, units with mechanical controls are usually the more economical option.
  • Many operators find this control type easy to use thanks to long familiarity.

Cons:

  • Knobs, switches, and some types of buttons protrude from the surface of the refrigerator, making them more likely to be damaged from impacts than flat electronic controls and offering more places for grime to get caked in and bacteria to multiply.
  • Mechanical controls cannot be locked, so customer-facing refrigeration equipment often have difficult-to-reach controls, either on the back of the unit or behind a panel.
  • Units with mechanical controls often use dial-type thermostat readouts that are more difficult to read than digital displays.

Electronic Refrigeration Controls

The simplest electronic refrigeration controls will use buttons to adjust the temperature and set defrost cycles. The buttons may be rubber and extend out a bit from the control pad, or be in a flat membrane pad, which is easier to clean. Higher-end refrigeration often features touchscreens, which require less pressure and offer more graphics-driven controls. With increased flexibility in the display, these units often offer more customization and record-keeping options.

Pros:

  • Most electronic controls allow you to select a precise target temperature.
  • Electronic controls open up more options, such as wireless monitoring, alarms, password protection, and diagnostics.
  • Digital temperature displays offer easier readability.
  • Precise temperature monitoring and reduced defrost cycles result in energy savings.

Cons:

  • Controls that aren't properly sealed by the manufacturer can be damaged by food or water.
  • Typically more costly than models with mechanical controls.