Scientists define cold as the absence of heat. But the F&B executive knows there is no such thing as the “absence of heat” in a hotel kitchen. So we need refrigeration equipment, and lots of it, to store food and beverages at safe or desired temperatures. Let’s explore this scientific definition a bit further as it applies to the theory of refrigeration.

Refrigeration is not about putting cold into a walk-in box. It’s about removing heat from the refrigerated space (and from the food put into the cooler or freezer). But heat (a form of energy) wants to flow from a higher temperature space to a colder temperature space. The purpose of the insulation, door gaskets, and strip curtains is to keep the heat out of the refrigerated box, not to keep the cold inside. Every time the door is opened, warm, moist air sneaks into the box, and more compressor energy [money] is required to remove this infiltrated heat and maintain the temperature setpoint.

So where do you recoup the savings? Start by walking through the kitchen and evaluating the condition of each piece of refrigeration equipment. Remember, a refrigeration package includes ice machines, under- counter drawer coolers, refrigerated prep tables, reach-in freezers and coolers, blast chillers, milk coolers, soft-serve machines, and drink machines—all running 24/7—extracting heat and dumping it back into the kitchen. In turn, this places additional load on the kitchen air conditioning, which is just another refrigeration system working hard to pump heat out of the kitchen.

Employ best practice.
Don’t let staff prop open walkin doors for the convenience of loading. While you’re at it, keep the lid down on those ice bins. Check thermostats to ensure that refrigerators or freezers are not set at a lower temperature than needed. Inspect door gaskets and strip curtains, and check out the auto door closers.

Proper airflow is an important part of refrigeration. When the coils are clogged and dirty, the compressor works harder and fails sooner. Clean evaporator coils (inside the refrigerated space) and condenser coils (outside the refrigerator or on the roof) at least quarterly. Make sure evaporator coils are not blocked by product or plastic bags that can get sucked up onto the face of the fan-coil package.

Let’s be honest. The lights in your walk-in are always on. It’s not convenient to turn them off. So, replace the light bulbs in the walk-in refrigerator with Energy Star rated compact fluorescent lamps (CFL). A regular CFL works fine in the refrigerator, but for the freezer get a CFL rated for low temperature. Not only do you save energy on lighting, you reduce the heat load in the refrigerator and compressor run time. Look around the kitchen. Are there glass door units with display lighting inside or outside that can be turned off or removed?

Equipment tune-up.
Solicit the hotel engineering department to tune up the “cold side” of your operation with low-cost retrofits, including strip curtains, door gaskets, and more efficient evaporator fan motors (i.e., electronically commutated motors [ECM] or permanent split capacitor [PSC] motors) in the walk-in cooler and freezer. Ensure that walk-in doors shut all the way; repair or replace broken auto-closers, lubricate door hinges, and realign sagging doors.

Find the time clocks that control the freezer defrost, and set them properly. Time clocks might be located on top of or underneath freezers or on the wall. There is a clock for each freezer. In less humid areas of the country (e.g., California), the number of daily defrost cycles can be reduced from four to three and sometimes two. Each cycle should be about 15 minutes long. Never defrost between noon and 6 P.M. That’s when you pay the most for electricity.

Try turning off door heaters on reach-in freezers. If sweating and dripping occurs, turn them back on. If not, you just saved 50 watts per door for the life of the unit.

Specify efficiency.
Although you aren’t going to tear out the walk-in cooler, there comes a time when an individual piece of refrigeration equipment has reached the end of its effective life. It’s simply time to replace it with a more efficient model. Specify Energy Star for reach-in refrigerators and freezers. Many electric utilities offer rebates for refrigeration equipment that meets or exceeds the Energy Star level. Check out the energy- saving calculators and rebate finder on EPA’s Energy Star website [www.energystar.gov].

Ice machines are often candidates for replacement as they are used and abused in the commercial kitchen. They also are among the few pieces of equipment where oversizing does not have an energy penalty. Not only does this offer extra ice-making capacity, it permits the unit to be operated off-peak—consuming energy at a lower cost and reducing the heat load on the space (assuming it is a packaged unit with the condenser coil on top). To operate off-peak, control the unit with the building’s energy management system or install a time clock. Talk to engineering. Note that the “fuel economy” of one machine may be better than its competition. Check out the list of qualified ice machines on PG&E’s Food Service Technology Center website [www.fishnick.com/saveenergy/rebates/ice/].

Even if you don’t get the California rebate, you do get the energy savings by specifying a model on this list.

Don Fisher, president/CEO of Fisher-Nickel, Inc., manages the Food Service Technology Center in San Ramon, California. This center collaborates with the Commercial Kitchen Ventilation Laboratory in Wood Dale, Illinois, to develop and apply standard test methods for evaluating the performance of food service equipment. The program is funded by California utility customers and administered by the Pacific Gas and Electric Company under the auspices of the California Public Utilities Commission.