The vending/OCS industry represents a relatively untapped opportunity for energy conservation through efficient practices. However, recent government standards have resulted in more energy efficient machines that vending operators can present to customers as environment enhancing benefits.
In January, I reviewed the scope of actions that vending operators can consider to introduce a “green” initiative. This month, we will look specifically at how government standards have impacted energy efficiency in beverage vending machines.
HOW THE GOVERNMENT CLASSIFIES BEVERAGE VENDERS
The Department of Energy (DOE) classifies beverage vending machines into two distinct classifications: class A machine (fully-cooled machine) and class B machine (any beverage vending machine not considered class A). The DOE recognizes that fully-cooled beverage vending machines generally have glass fronts, therefore designates these machines ‘‘Class A.’’ By doing so, ‘‘Class B’’ machines, by default, are any beverage vending machine not considered class A.
Class A — fully-cooled machines — is comprised of machines that cool the entire internal volume in a refrigerated unit. Class A machines generally use ‘‘shelf-style’’ vending mechanisms and tend to utilize a transparent (glass or transparent polymer) front.
Since the next-to-be-vended product is visible to the consumer and any product can be selected off the shelf, all bottled or canned beverage containers are enclosed within the refrigerated space.
Class B — zone-cooled machines — is generally composed of machines that have an opaque front (which provides better insulation from ambient conditions) and utilize a ‘‘stack-style’’ vending mechanism. These machines are installed either indoors or outdoors. The energy consumption of an outdoor machine may vary given changes in ambient conditions. The average energy consumption of these machines is very similar to that of machines installed indoors.
Typically, unlike the class A machines, only a fraction, or a zone of the volumes of a class B machine (usually the bottom third of the machine) is cooled. Hence, the use of the term “zone-cooled.”
COMPONENTS OF ENERGY EFFICIENCY IN DRINK VENDERS
Technological components within a beverage vending machine that may impact its energy efficiency include the sealed cooling unit, evaporator/circulating fan, lighting, insulation, thermostatic and electronic expansion valves, and door-sealing systems. In addition, T8 lamps with electronic ballasts, T5 fluorescent lamps, dimmable light emitting diodes (LED), electronically-commutated fan motors with engineered impeller and venturi rings, and capillary tube systems with liquid-suction heat exchangers often are considered.
Some manufacturers are researching other technologies such as Stirling refrigeration, which uses temperature differential to provide electrical power. Also, the inclusion of an energy-management device that restricts energy use based on motion detection can also be important.
In developing industry energy standards, DOE considers the following nine technologies as viable design options for improving energy efficiency of beverage vending machines:
- More-efficient lighting;
- More-efficient evaporator fan motors;
- Evaporator fan motor controllers;
- Improved evaporator design;
- Insulation increases or improvements;
- Improved glass pack (for Class A machines);
- Higher efficiency condenser fan motors;
- Improved condenser design;
- More-efficient compressors.
GOVERNMENT DEVELOPS PERFORMANCE STANDARDS
While the DOE classifications help differentiate green vending potential, the Environmental Protection Agency (EPA) has developed energy performance criteria for beverage vending machines as part of its Energy Star certification program.
Energy Star is basically a 2-tiered set of specifications for refrigerated beverage machines. Tier 1 has been in effect for new machines since 2004, and for refurbished machines since 2006 while Tier 2 criteria went into effect in 2007 for new machines.
Originally, the top 25 percent of beverage vending machines qualified as Energy Star Tier 1. As manufacturers produced more-efficient machines, a majority of the machines being built meet or exceed Tier 1 levels.
More than 90 percent of indoor/outdoor beverage vending machines meet the Energy Star Tier 1 specification, and a large volume of indoor-only machines meet this specification as well.
ENERGY STAR RATING: WHAT IT MEANS
Earning an Energy Star rating means products meet strict energy efficiency guidelines set by the EPA and the DOE. This designation indicates:
- Energy Star qualified vending machines are estimated to be 50 percent more energy efficient than standard machine models.
- Energy Star qualified vending machines incorporate more efficient compressors, fan motors, and lighting systems to keep beverages just as cold and the machine visible while using less energy.
- Energy Star qualified vending machines come with a low power mode option that allows the machine to be placed in a low-energy lighting and/or low-energy refrigeration state during times of inactivity.
Operators are encouraged to visit the Energy Star website (energystar.gov) for product specifications and listing of qualifying products.
In order to receive the Energy Star label, a vending machine must meet the energy consumption criteria set forth by the most current version of the specification and must incorporate software that can operate the vending machine in a low-power light state, low-power refrigeration state, or a whole-machine, low-power state.
KEY VENDING ENERGY CONSERVATION FACTORS
The major areas of concern relative to energy conservation by vending machines are temperature, surroundings, and lighting. Vending machine consumption will be a function of:
- machine dimensions (vendible capacity);
- machine environment (indoor/outdoor);
- machine throughput (product movement);
- machine availability (continuous/intermittent);
- machine type (non-refrigerated/cold/frozen/combo);
- machine lighting (fluorescent/incandescent/LED)
Industry studies have revealed that approximately one-third of the energy consumed by a vender results from lighting use (e.g. T8 fluorescent, T12 fluorescent, ballasts, LED, slim-line output) while an even larger proportion is attributed to temperature (e.g., refrigeration compressor, motor, and system optimization).
CLASSIFICATIONS BASED ON VENDIBLE CAPACITY
DOE beverage vending machine classifications are not defined by size, but instead are based on design configurations regardless of whether rated for indoor or outdoor use. As a result, DOE classifications include equipment of varying sizes.
In nearly all other refrigerated units, energy use tends to be a function of size; hence, it is argued that for beverage vending machines, the standard for each class should incorporate dimensions prescribing a maximum amount of energy use that relates to size of equipment within the class.
In other refrigeration units, this factor is referred to as the normalization metric, which accounts for variation in size (e.g., refrigerated volume) and allows the maximum allowed energy use to vary by the size of the equipment. DOE embedded a similar factor into its classifications for beverage vending machines by including a refrigerated volume metric.
Using refrigerated volume as the normalization metric for measuring daily energy consumption for all equipment classes of beverage vending machines enables an effective means for data collection in an attempt to define vendible capacity to refrigerated volume.
AUTOMATIC LOWER POWER MODE CAPABILITY
In addition to meeting the 24-hour energy consumption requirements of the DOE, qualifying machines should be equipped with hard-wired controls and/or software capable of automatically placing the machine into a low power mode during periods of extended inactivity. This will further facilitate energy savings.
The machine should be capable of operating in the following low-power modes for extended periods of time:
1) Lighting low-power state — lights turned to “off”;
2) Refrigeration low-power state — average temperature allowed above 40 degrees Fahrenheit;
3) Whole-machine low-power state — lights off and refrigeration in a low-power state.
Additionally, the machine must be capable of automatically returning back to normal operating conditions at the conclusion of a period of inactivity. Low power mode-related controls and/or software should be controlled on-site by the vending/OCS operator or machine owner.
The EPA’s goal in including low-power mode requirements is to ensure that existing machine software capabilities are available and may be used to its full potential based on individual requirements of the site client. However, machines that dispense temperature sensitive items, such as dairy products, must be more carefully calibrated so that the low-power state does not contribute to product spoilage.
POWER FACTOR VARIABLE
The Energy Star rating system also includes a variable referred to as “Power Factor.” This is a measure of the efficient use of power consumption by a specific device. Most vending machines prior to the recent focus on energy conservation may have operated with a power factor in the 60 percent range.
A vending machine with a Power Factor of 60 is likely to draw 200 watts of power but only 120 watts would be effectively used. While the unused portion of the electricity (40 percent) recycles back toward the power grid, minus associated transmission losses, the vending equipment would be labeled an inefficient user.
Current Energy Star standards require machines to have a Power Factor of at least 90 percent.
STANDARDS REQUIRE AUTOMATED BENCHMARKING
The Energy Star rating process requires manufacturers to input energy performance metrics into an automated benchmarking system that determines changes in energy conservation.
It is important to note that many LED lamps have been designed to be very energy efficient, some resulting in significant savings compared to a fluorescent bulb and lasting several years longer.
Care must be exercised when selecting LED lamps, as not all products result in energy conservation. In fact, some LEDs designed to make a vending machine brighter may consume as much or more power than the fluorescent bulbs they replace. It is for this reason that a review of lab results of various LED lights may be wise.
Next month, we will explore how the energy efficiency can improve relations with clients.