In the beginning, there was ice – the original refrigeration. Some of us may remember our grandparents referring to the big appliance in their kitchen as “the icebox” (even though it was a modern refrigerator-freezer) in tribute to the actual icebox they remembered from their childhood. We’ve come a long way in terms of refrigeration technology since the “Ice Man” delivered huge blocks of frozen water door-to-door. But given the enormous amount of electricity that refrigeration can consume, one of the most important decisions a business owner can make is how to create utility savings solutions by upgrading their refrigeration systems.
A wide array of businesses involved in the sale or storage of food require some form of commercial refrigeration. These include food retailers ranging in size from small convenience stores to large supermarkets, restaurants, schools, hotels, hospitals and nursing homes (which also need refrigeration to store certain types of medicine). And since refrigeration runs ‘round the clock and can account for up to half of all the energy used by some of these businesses, investing in energy efficient refrigeration equipment can produce quick paybacks and impressive long-term savings.
How important is energy efficiency for commercial refrigeration? Consider that over the life of a typical piece of commercial refrigeration equipment, the cost of the electricity needed to run it can be up to six times as much as the price of the equipment itself.
Selecting the type and size of a refrigeration system that’s right for your business’ needs can have a big impact on your energy costs. Most businesses with large refrigeration needs, like supermarkets, have what’s known as a Centralized Direct Expansion, or DX, system. In a DX system, the compressors are located together in a single space, often behind the building or on the roof, with lines running from that unit to the store’s display cases and refrigerated storage areas. Supermarkets may have one DX system for display cases with foods needing low-temperature refrigeration, like ice cream and frozen dinners, and another for foods needing medium-temperature refrigeration, like meat, dairy products and juices. For businesses with smaller refrigeration needs, a distributed system may be preferable to a DX. Unlike a DX, a distributed system uses individual compressors located near the display cases they serve. The proximity of the compressors and cases results in less piping through the store and a smaller refrigerant charge – which can also result in a decrease of refrigerant emissions. Proper sizing is also a key consideration in commercial refrigeration, since a system that’s oversized in terms of cooling capacity or cubic footage will not only cost more initially, but will be more expensive to operate because it will use more electricity.
If you’re replacing your commercial refrigeration or freezer equipment, it’s wise to look for the ENERGY STAR label. Equipment that’s earned the ENERGY STAR label is, on average, 20% more efficient than standard equipment because they’re designed with high-efficiency compressors and variable speed motors for condensers and evaporators. ENERGY STAR-certified equipment may be eligible for energy efficiency rebates under utility or government-sponsored incentive programs. An Ecology Action energy efficiency expert can provide you with details. While most commercial refrigeration and freezer equipment is eligible for ENEGY STAR certification, certain types of equipment – including ice cream freezers and prep tables – are ineligible.
Although a complete replacement of your business’ refrigeration system is going to produce the greatest amount of energy savings, there are also several low-cost measures you can put into place that will help cut your energy bill without incurring the capital expense of a full overhaul. One of the energy saving measures that has gained popularity in recent years is de-humidification filters. Each time the door of a refrigerator unit is opened, warm air comes in and mixes with the cold air to create moisture. This moisture causes the unit’s internal temperature to rise and triggers the compressors to start up to bring the temperature back down. De-humidification filters use a desiccant to draw moisture from the air inside the unit, allowing the compressors to run less often and reducing electric use. These filters, which are easily installed, can also help eliminate odors and bacteria that grow in moist environments.
Energy savings can also be achieved inexpensively by making sure the doors on refrigerators, freezers and display cases are tightly sealed to prevent warm, moist air from leaking in to the units, increasing their energy use and possibly leading to the spoilage of food. Door gaskets and automatic door closers should be checked regularly, and repaired or replaced if they’re damaged or worn. The presence of frost on shelves or food products is a tell-tale sign of worn gaskets or automatic closers that aren’t working properly.
Speaking of doors, selecting the right type of doors for refrigeration and freezer units can also have an impact on energy savings. Solid doors offer better insulation than glass doors, but glass doors allow users to find what they’re looking for faster, so doors can be closed sooner. Glass doors also allow employees or customers to see the contents of the unit, which can reduce the number of unnecessary door openings.
Low-cost plastic curtain strips can be an inexpensive energy efficiency measure for walk-in refrigerators. Installing them behind the walk-in’s door lowers the amount of cooled air lost when employees walk in and out. Shorter versions of plastic curtain strips perform the same function on grocery store display cases, reducing the cool air loss from the case while still providing customers with a clear view of the products for sale and keeping them in easy reach. Additional energy savings can be realized in refrigerated display cases by placing a continuous cover, or “night curtain” over the cases during overnight hours, limiting the loss of cool air when the store is closed.
A “two birds with one stone” approach to energy savings for food stores with refrigerated display cases is the replacement of fluorescent lighting with LEDs. Not only do LEDs use much less electricity than fluorescents (and last much longer), but the fact that they generate very little heat means that the lighting in the display case isn’t making the refrigeration work harder.
Making sure your refrigeration equipment receives proper maintenance is another way to achieve energy savings at little or no cost. For example, the simple step of cleaning your system’s cooling coils several times a year can go a long way toward making your equipment run more efficiently. The coils – which are either underneath or behind many commercial refrigeration units – can get coated with dust, dirt or cooking grease, especially in restaurants or kitchens. Dirty coils have to work harder, using more electricity and raising your utility bill. In addition, you should make sure that there is enough room around the coils to ensure good air flow. Maintenance measures also extend to having your refrigeration equipment serviced regularly to clean condensers and evaporators and to check the operation of fans and defrost systems.
Energy efficient refrigeration not only saves money on electric costs, but can generate other savings for businesses as well. For example, high-efficiency motors and controls run refrigeration systems only when they call for cooling. This can be especially important for the produce sections of grocery stores, since fruits and vegetables dry out when they’re exposed to too much airflow, resulting in costly inventory losses.
Refrigeration has come a long way since we relied on blocks of ice to keep our food fresh. Between advances in energy efficiency technology and proper maintenance, businesses that rely on refrigeration now have a number of options to control their electric use and produce significant energy savings.