Restaurants tend to contain a great deal of energy-intensive equipment, such as deep fryers, walk-in or reach-in coolers, and often multiple stoves and ovens. Because of all the heat-producing equipment and odour-producing cooking, restaurants often need to have air conditioning and significant venting in order to keep their customers comfortable and to successfully circulate air and prevent the suffocation of the kitchen staff. In most larger or newer restaurants, the teenage dishwasher in the back is assisted by an industrial dishwasher that can wash, sterilize and dry racks of dishes and cutlery in just a few minutes.
All of this equipment takes up energy. All of this energy costs restaurant owners money. All of that money would probably be much more enjoyable if it were in the profit column instead. In some cases, replacing highly inefficient equipment with newer, better models may be the only option. In other cases, equipment may simply need to receive more regular maintenance in order to keep it functioning at its most energy efficient. The third option is retrofitting.
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As you can see from the graph above (courtesy of Energy Star), food preparation leads the pack in energy use, followed by HVAC systems. Since ovens and deep fryers do not tend to have many retrofit options available, I am going to focus on retrofitting HVAC and refrigeration systems. Together these two groups of equipment account for 34% of energy used by a typical restaurant, and there are many possible courses of action available to become more efficient.
With refrigeration, there are a few simple actions that can make an immediate dent in the amount of energy that gets wasted while attempting to keep food cool. Simply maintaining the existing equipment is a good starting point, followed by installing defrost timers and more energy efficient lighting. In many walk-in coolers, incandescent lighting is used which can generate a significant amount of heat over the course of a day and put an added and unnecessary load on the refrigeration system. Switching to CFLs can cut the heat output by 75% and saves energy twice over: less energy is used to light the walk-in cooler, and less energy is used to maintain the temperature. In terms of cutting the 13% energy used by lighting in general, switching to CFLs is a great step for the entire restaurant.
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Another simple solution for cutting refrigeration energy use is to minimize the entry of warm air and the escape of cooled air from the walk-in. Strip curtains and auto door closers ensure that every time cooks are dashing in and out of the walk-in cooler, the extra load on the refrigeration system is minimal. An auto door closer is particularly valuable, since a cooler door left open overnight can cost the restaurant hundreds of dollars in spoiled food as well as increased energy bills.
As for the HVAC system, the easiest way to save energy is to adjust the set points of the thermostat. For example, if you are attempting to keep your customers comfortably cool during the summer, you can save 12% to 15% of your air conditioning costs by raising the set point just 3 degrees Fahrenheit (2 degrees Celsius). Of course, raising the temperature in the restaurant may not always be a viable option since customers may not be as comfortable. In this case, there are retrofits that can cut energy use while maintaining temperature requirements.
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If a restaurant has already implemented simple fixes and wants to slash their refrigeration or air conditioning energy use more aggressively, Smartcool offers a more elegant solution with its ECO3. Wired between the thermostat and the existing equipment, the ECO3 improves the performance of the compressors within these systems and saves an average of 15% kilowatt hours while maintaining temperature requirements.
For more information on restaurant energy use, read Energy Star's guide here.
This is the second in a series of posts on the benefits of retrofitting systems in a variety of different building types.
