Harsh Environments Are Tough on Refrigeration Equipment
Units in c-stores, restaurants need regular maintenance in order to keep running smoothly
Operational conditions in restaurants and convenience stores (c-stores) are notoriously hard on refrigeration equipment. High temperature fluctuations, foot traffic, dirt and debris, grease, and general abuse from employees and/or customers can wreak havoc on units, particularly if they are not well maintained.
Scheduling maintenance in these facilities can be difficult because they are usually open many hours of the day — if not all day — and there is never a convenient time to interrupt operations. However, if units are not regularly serviced and maintained, they may break down more frequently, which is usually even more inconvenient — and expensive — for the end user.
Restaurants often contain a variety of refrigeration equipment: everything from reach-in refrigerators and freezers to ice machines, salad and sandwich prep stations, beverage dispensers, walk-in coolers, and freezers. The restaurant environment is very hard on refrigeration equipment, and regular maintenance is often overlooked, said Adam Armistead, field service supervisor for Electric Motor Repair in Rosedale, Maryland.
“Problems for poorly maintained equipment are vast,” he said. “They can be something as small as a few degrees off temperature to as large as a total equipment replacement. Failed compressors and fan motors, leaking or restricted refrigerant systems, and damaged evaporator plates in ice machines are some of the more common problems in equipment that has not been maintained.”
Justin Cockle, director of service operations at The Arcticom Group in Murrieta, California, notes that many restaurant customers struggle with maintenance because there is often no good time to interrupt their operation for equipment work.
“The lack of upkeep causes the equipment to fail at a higher rate, consume more energy, and shortens the life of the equipment, all of which affects the facility’s bottom line,” he said. “Spending money upfront reduces overall costs and downtime of equipment.”
To that end, one of the most important aspects of regular maintenance is making sure the condensers are consistently cleaned — monthly, quarterly, or yearly, depending on the type of condenser and environment in which the refrigeration unit is operating, said Travis Scola, innovation manager at Minus Forty Technologies, Georgetown, Ontario. Failure to perform regular cleaning of the condenser can result in overheating of the compressor, leading to its failure.
“Most units sold today are self-defrosting, but if the restaurant has manual defrost units, defrosts should be scheduled regularly to prevent serious damage to compressors,” he said. “Fin-style condensers will require more frequent cleaning. Make sure to use separate cleaning materials for the outside and inside of units, to prevent any transfer of bacteria that could contaminate the food. And keep cleaning equipment for refrigeration units separate from those used for floors or other equipment in the restaurant. In all matters, be sure to follow the manufacturer’s cleaning instructions.”
The cleaner used on the condensers of air-cooled equipment will vary depending on the type of contaminants in the coil, whether it’s grease or just dirt and debris, said Denny Martin, technical support engineer at Embraco, Duluth, Georgia. Some cleaners come in aerosol cans and are rinse free, while more aggressive chemicals may be needed to dissolve grease on coils, and these usually require a water rinse.
“Performance checks with temperature drops, amp draws, and general cleaning should be performed as part of a regular maintenance routine as well,” he said. “Larger walk-ins with additional controls may require more maintenance checks, and superheat or subcooling calculations may be needed to verify correct refrigerant charge. Compressor and condenser motors should be checked with a megohmmeter as well.”
Evaporator fans should also be checked, said Scola, as these require proper air circulation in order to operate correctly. Employees and suppliers should know how to pack the units so that airflow is not impeded.
“When cleaning the glass and the doors, conduct a visual inspection of the gaskets all the way around the seal to make sure there are no gaps or tears,” he added. “Changing a gasket is relatively easy and costs very little when compared to the energy costs that are incurred if the unit must work overtime.”
Regular maintenance should also include cleaning out the drain lines, checking thermostat differentials on all equipment, and ensuring the defrost circuits on freezers are functioning properly, said Armistead. In addition, the door frame heat of walk-in coolers and freezers should be checked to ensure that it is operating, and door closers should be checked for proper function.
“Ice machines and bins also need to be cleaned, sanitized, and water filters changed, and glycol chillers should be checked for proper mix and for algae buildup in the reservoir,” he said. “I suggest this maintenance be performed every six months, but after the first good cleaning, we will look at how dirty the equipment gets and then make a determination with the owners about whether the frequency needs to be increased or decreased.”
C-stores often have the same types of refrigeration equipment as restaurants, so maintenance procedures are usually the same as those described for restaurants. The difference is that c-stores typically have more self-contained cases, frozen beverage machines, and ice machines, as well as walls of built-in coolers and freezers. In addition, grease is less of an issue in c-stores, but they often have more dirt, dust, and debris due to large amounts of foot traffic.
“Independent c-store customers can be hard on their equipment in ways they may not understand,” said Cockle. “It’s not necessarily related to abuse, but to the overall conditions of their locations. Most struggle with the needed electrical requirements for plugging in multiple cases, which puts an electrical strain on their panel, causing refrigerated cases to fail along with other equipment.”
The other factor that often affects self-contained refrigerated cases is the location’s space temperature, he said. That’s because most cases are designed to operate within a certain ambient temperature, but in many c-stores, the air conditioning system was not designed for the added heat load, and it may be in poor shape. These conditions can result in case failures, as well as causing air conditioning units to work harder, which costs more money for the store owner.
In addition, c-store owners often try to cut costs by not running their air conditioning systems on hot days, which is tremendously hard on compressors and fan motors, said Armistead.
Another problem with c-stores is that the equipment may not have been installed correctly in the first place. As Scola noted, the key to installing any stand-alone refrigeration unit is to ensure that the unit has a dedicated power line and space around the cabinet for proper ventilation. Due to space limitations, owners will often try to squeeze equipment into confined spaces, and this can result in the breakdown of equipment due to poor ventilation.
As far as maintenance is concerned, Armistead has found that once equipment is installed in a c-store, it is usually never touched again until there is a problem.
“Equipment is usually installed and then forgotten about — left to live out its service life with little to no preventive care,” he said. “This translates into big trouble for the owners in the form of costly parts failing and loss of revenue, because let’s face it, nobody wants to drink a hot beer at the end of a long work day.”
Lack of maintenance can also lead to larger energy bills for owners, said Martin. That’s because c-stores usually have more commercial refrigeration equipment than restaurants, and poorly maintained machines have the potential to use excessive amounts of electricity.
“With restaurants, sometimes a piece of equipment that is down can be worked around, but with convenience stores, every refrigerated unit is part of their merchandising space and has significant impact on the store’s sales and, consequently, their potential to make money,” he said. “It is easy to see how poorly maintained refrigeration equipment can affect a convenience store’s bottom line.”
C-store and restaurant owners who invest in regular maintenance may also be interested in retrofits that can improve system performance while saving energy. These can include variable-speed technologies, electronically commutated motors (ECMs), and new controls.
“Reach-ins and other unitary equipment with variable-capacity compressors can adjust to heat loads very precisely to consume less energy,” said Martin. “Equipment that uses natural refrigerants like R-290 (propane) can also have a huge effect on energy usage. Embraco has supported the switch to hydrocarbon refrigerants in the U.S., and it’s been exciting to see the efficiency improvements with this technology.”
Energy management systems (EMS) can also be retrofitted into virtually any application, noted Cockle, and there are a host of new technologies, including standalone controls and WiFi-compatible controls, that can be managed through smartphones.
“The challenge is that the return on investment (ROI) lengthens the deeper we get into controlling equipment,” he said. “The long-term savings is there; however, the upfront investment can be difficult for independents to afford. Larger franchises and chains have the capital to carry longer ROI, and they typically better understand the savings and benefits between the old mechanical controls versus the newer controls.”
For c-store and restaurant owners who are truly interested in improving the performance of their equipment, Cockle contends that the best way to do it is to invest in quarterly maintenance. Simply doing that will reduce service calls, downtime, energy consumption, and capital expenses over time.
As Armistead noted, “Poorly maintained equipment will bring plenty of headaches for the owner of any restaurant or c-store, which will ultimately take a chunk out of the bottom line. I will always recommend that a customer pay my team to maintain their equipment instead of paying us to replace their equipment.”
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