temperature@lert blog

  • Roll Up Your Sleeves - Time to Tackle that Walk-In

    Wrapping up our Walk-In and Commercial refrigerator preventive maintenance series.

    We’ve looked at walk-in and commercial refrigerator operation, theory, major components, preventive maintenance options, and a host of other issues including the dreaded home refrigerator cleaning. So what’s a manager to do? Time to make a plan.

    What’s needed in commercial and walk-in refrigerator and freezer preventive maintenance?

    The third piece of this series titled Walk-In Refrigerator Preventive Maintenance Components & Checklist offered the following list.

    1. Clean condenser coils

    2. Clean evaporator coils, defrost if needed

    3. Clean fan blades and fan grills

    4. Check thermostat vs actual thermometer

    5. Clean interior and door gaskets with mild detergent

    6. Inspect and clean drain lines

    7. Relocate items that block airflow inside or outside of unit

    8. Check door latch and gaskets are intact and working properly

    9. If needed, thaw ice from coils

    10. Listen to note any wobbles, rattles or other unusual noises during operation

    The items above can be performed by most organizations if proper, trained resources are allocated. For businesses that operate every or most days, maintenance listed above is recommended at least quarterly but more frequently for installations where high heat and humidity are present (kitchens or summer months), or where high dust and dirt levels clog up condenser coils, outdoors or in kitchens for example. Operations with significantly less use such as public school cafeterias that serve only lunches can perform quarterly or biannual service for most installations.


    Figure 1. Images from a website that provides very helpful commercial and walk-in refrigerator maintenance. Frost bound evaporator coil (Left Image) and well cleaned and maintained evaporator cooling fans from the site (Right Image).

    Additional items not included above and more suitable for professional service companies are as follows.

    1. Inspect all drain lines and pans for blockage due to dirt or ice accumulation

    2. Inspect electrical wiring connections for tightness and corrosion, especially in outdoor installations

    3. Lubricate moving parts (hinges, motors) as specified in the owner’s handbook

    4. Inspect all pressure connections for tightness and corrosion

    5. Perform manufacturer specified electrical and mechanical checks on compressor, automatic defrost components, thermostat and other controls and components

    6. Check operation of all filters and driers

    7. Check refrigerant level and pressure

    Figures 3 & 4: Professional refrigerator maintenance requires specialized equipment and knowledge. Some examples:  Left Image  Right Image

    Many of these items listed above require specialized skills, training and in some cases instruments, so such maintenance generally left to professionals. This maintenance is recommended quarterly or at least semiannually for high use installations such as restaurants and food stores. Those with challenging installations (hot, humid, outdoor, high dust level environments) will want to perform quarterly service at a minimum.

    Additional items to consider for optimum operation that generally are able to be handled by managers or designated staff are as follows.

    1. Maintain temperature controls to keep food at the recommended range during all seasons. This may require seasonal setting changes depending on how constant the environment (temperature and humidity) around the door and compressor coils is during the year.

    2. Insure glass door refrigerated display cases use their door defogger in high humidity environments to avoid unnecessary opening’ but turned down or off in winter or low humidity environments.

    3. Check your electric bill. Dirty equipment can add significantly to operating costs and are a good indicator service is needed.

    4. Verify cooler temperature with a good quality thermometer to determine thermostat accuracy or whether an offset is needed.

    One source notes commercial refrigerators that do not receive proper preventive maintenance can result in an additional $600 or more in electrical utility cost per year. (Link to Source)

    Figure 3 (Left) Regular preventive maintenance can also prevent costly service calls as is demonstrated in the graphic on the left. (Link to Image) In this case, one failure would be equal to eight (8) years of annual maintenance. Not only can such maintenance prevent equipment failures, but also lower electric bills and product loss.

    Figure 5. Link to Commercial Refrigerator and Freezer Troubleshooting Guide

    For those who want to perform most preventive maintenance themselves, the DIY-ers, it is helpful to know where to start when your units are misbehaving. The table above provides a quick guide to many common problems, some possible causes and solutions. Although no list can be fully comprehensive, this table will help diagnose many issues and help determine when and if professional service is needed.

    Commercial refrigerators and freezers and home refrigerators both operate on the same principle in most cases. The biggest difference is the amount of use commercial units receive. High volume grocery and convenience stores as well as restaurants, cafes and diners depend on their refrigerators and freezers for their business health. When these establishment suffer outages it can cost businesses a day’s or more income, loss foodstuff, and loss of goodwill. Regular customers will potentially go elsewhere and may find a new “favorite” place, meaning permanently lost revenue.

    Whether businesses opt for DIY programs augmented by emergency service calls or annual professional service contracts, regular preventive maintenance as well as attention to operation of the units can help prevent many if not most outages. Regardless of the choice, understand how the units work, the preventive maintenance schedule involved, and potential costs and savings is critical to making an informed decision. And if you’re lost, go home and clean your household refrigerator to remind yourself why regular cleaning and maintenance is important.

    Website showing typical home refrigerator maintenance. Link to Image

    Temperature@ert provides cost-effective, fault-tolerant wireless temperature monitoring solution for organizations of all sizes. Our products and services can help bring a food processor, distributor, wholesale or retail outlet into compliance with minimal training or effort. For information about Temperature@lert’s Cellular and SensorCloud offerings, visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.

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  • Cats, Dogs and Animals in Shelters

    animal shelter pets, animal shelter, dog, dogs, pets, temperature monitoring

    It's the look of love in eyes of those looking to adopt a new pet that makes your of job of constant care-taking worth it. But it's not just the giggle of the little boy who found his companion in a playful puppy or the fluorescent smile spread across the face of the little girl when she picks out a new kitten that's going to be her new best friend that warms your heart, but also, that you did good work in finding a home for an animal that deserves all the love, care and attention in the world.

    But, as an animal caretaker in a busy shelter, with animals in an out all the time, you know that there's a lot of work that goes into raising a playful puppy and a cuddly kitty cat. It's so much more than showering them with hugs and kisses, throwing the tennis ball and spooning with them at bedtime. It requires taking time out of your busy schedule everyday to walk them, feed them, clean them, take them to the vet for shots and check-ups and regular grooming them, just to list a few obligations for pet owners. Our pets might be our best friends, but they're costly and time consuming ones at that!

    Of course they need our unconditional love, but beyond the everyday chores that our pets rely on us for to stay happy and healthy, especially when they're in the shelter waiting to be taken home with a good family, as their temporary caretaker, you need to make sure that you are running a shelter that follows some pretty specific guidelines. It's of vital importance, not only to the health of the animals in your shelter, but also to the health or the human caretakers, that regulations, in terms of sanitation, feeding practices, medical attention, and of course, temperate environments.

    corgi, pet monitoring, pets, cats, dogs 

    You may not even realize it, but maintaining proper temperatures in your animal shelter is a critical practice that can greatly affect the health of the animals that are in your care. They not only expect you to feed them daily and shower them with affection, but they're banking on you to make sure that they are kept in units that are not too cold and not too hot. Just like us humans, animals are extremely sensitive to fluctuations in temperature and humidity, and unless careful the upkeep of proper ambient temperatures is observed, you'll have bigger problems than puppies who just want to be adopted.

    As the responsible and loving caretaker that you are, you want to be able to ensure that proper temperature and humidity levels are maintained, even in the middle of the night, long after your workday is over. Imagine coming to work on a hot summer morning to find that your air conditioner had failed at some point during the night. Without an automatic temperature monitoring system that offers text, e-mail or phone alerts, how could you even know that there is a problem that needs addressing? The truth is that you couldn't know until, unfortunately, it's probably too late. If you're lucky, you might just walk in and find that many of the animals in your shelter are simply dehydrated. If you're unlucky, however, you might walk in to work and find that the animals in your shelter have suffered severe heat stroke, which can actually be fatal. It's a morning at work that we promise; no one wants to walk into.

    The fear of losing a pet is one that exists in the mind of every loving pet owner and caretaker. The good news is, that you could never have to spend the day nursing animals back to health because there are preventative solutions that can ensure that the animals in your care are comfortable, safe and healthy round the clock, even when you aren't there to monitor temperature and humidity levels manually.


    Throughout this series, we'll take a closer look at why it's so important for animal shelters to monitor temperature and humidity levels, no matter the type of animals that are in your care. There are numerous problems that can arise if ambient temperatures aren't carefully observed and if you could save yourself the head and heartache of dealing with animals that are suffering because of their poorly monitored environments, why wouldn't you? 

    monitor temperature, temperature monitoring, pet shelter monitoring, animal shelter monitoring, RV temperature monitoring, dog monitoring

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  • Tackling Walk-In Refrigerator and Freezer PMs - Part 2

    Evaporator maintenance is only half the task, on to condenser loop maintenance.

    The previous piece in this series looked at walk-in and commercial refrigerator evaporator coil and associated hardware preventive maintenance. The evaporator coil’s name refers to the refrigerant, Freon or newer types like HFC-132a, being evaporated, that is turn from a liquid to a gas. Evaporation is a process that absorbs heat, just as liquid water needs to absorb heat to boil. The amount of “heat” absorbed when the liquid refrigerant turns into a gas is small, but that small amount of heat absorbed from the refrigerator or freezer compartment is enough to keep it cool. To help visualize this, think of a CO2 cartridge in a seltzer maker or BB gun after it is used: it feels cold. The liquid CO2 inside the cartridge is evaporating and absorbing heat from the surrounding air.

    The opposite takes place in the condenser loop. Here the gas is squeezed together by the compressor and turned into a liquid. And in doing so, the “heat” captured in the evaporator coil loop is released, heating up the compressor and condenser coils. Something like this happens when you are using a bicycle pump: the outlet of the piston tube gets very hot as many have found out when they inadvertently touched it. The air is not turned into a liquid, but compressing the air (gas) makes it hot and that heat can be more easily transferred to the air.

    This heat generated during compression is expelled when the condenser coils heated by the compressed gas or liquid inside release their heat into the air surrounding the compressor coils. The process allows the refrigerant to be reused to pick up more heat. It’s amazing to think that this process, turning a refrigerant liquid into a gas to cool the refrigerator, then compressing the gas back into a liquid to expel the heat, happens continuously in our home refrigerators year after year with little maintenance and few failures. This is a tribute to the power of technology, good engineering and quality manufacturing.

    Figures 1 & 2: Home refrigerator compressor and fan cooled compressor coils (Left Image) compared to commercial unit (Right Image) demonstrates similarities and differences, mostly in the larger size of the commercial unit.

    Like home units walk-in compressor loops require maintenance. In fact, maintenance in commercial units is in most cases required more often than in home refrigerators and is more important than evaporator maintenance. Evaporator components operate in a relatively controlled, clean environment. Compressor components operate in the ambient air: from hot summers and warm kitchens to cold winters where they can be covered with snow or ice. Dust, dirt, greases and oils in this environment are serious concerns because dust and greases can adhere and accumulate on compressor coils or fins blocking airflow and reducing cooling efficiency. To accommodate for accumulated dust and dirt the compressor runs harder, longer and gets hotter, meaning it will be more prone to heat related damage or failure. Additionally dirty compressor coils lead to higher energy usage and cost.

    Dust on the compressor coils is a significant issue in most sites. Unlike home units, commercial compressor coils often have fins attached to increase the ability to dissipate heat. Fans blow air across the fins and coils to help remove heat faster, and in doing so they draw in dirt, dust, greases and oils. The oils and grease stick to the coils and fins and coat them with a thin film, reducing heat transfer (cooling) efficiency. Additionally, these sticky films collect dust which then collects more dust, a process that ends up accumulating a significant amount of dust if not cleaned regularly.

    Figures 3 & 4: Dust covered condenser coils (Left Image, Right Image) prevent proper heat transfer into the air, reducing efficiency, leading to higher energy costs, reduced compressor life and in some cases, spoiled food, especially seafood and dairy.

    In the cases above, removing accumulated dust can be done by hand, vacuum cleaner with brush attachment or with a soft brush, being careful not to damage cooling fins, especially if they are very thin like those in a home window air conditioner. Additional cleaning with a spray cleaner like that used for the evaporator coils will help removed accumulated films. Care need be taken to avoid spraying cleaners into electrical components like fan motors; unplugging the unit or tripping the breaker during cleaning can help avoid problems.

    The compressor itself as well as metal tubing connected to the compressor and cooling coils should also be cleaned. Here a soft cloth possibly dampened with appropriate cleaners can be used. Be careful if you clean the compressor and attached tubing right after powering down the unit because they may be very hot, enough to cause nasty burns in some cases.

    Figures 5 & 6 Professional maintenance companies can provide both preventive and repair services when the job is too big or complicated or staff is not available. In the Left Image a service technician prepares a replacement compressor in a roof mounted unit. In the Right Image a commercial refrigerator is shown after professional cleaning and service.

    The DIY vs Professional preventive maintenance is a decision managers must make. If you’re wondering if your or your staff is capable of proper cleaning and preventive maintenance, check out this YouTube video: Cleaning Your Condenser: Condenser Cleaning Video

    There are many things a professional service regularly do that most managers or staff would find difficult when it comes to commercial and walk-in refrigerator maintenance, such as checking refrigerant pressure and electrical performance. Regardless of whether or not DIY or professional services are used for routine cleaning, annual or even biannual professional service is recommended, the latter for those units that run hard and whose compressor and compressor coils are in hot areas or those prone to accumulating dust and dirt.

    Our next and final piece in the series will review the discussion, add some items to think about, and provide some thoughts on how to keep ahead of the maintenance requirements of commercial refrigerators and freezers.

    Temperature@ert provides cost-effective, fault-tolerant wireless temperature monitoring solution for organizations of all sizes. Our products and services can help bring a food processor, distributor, wholesale or retail outlet into compliance with minimal training or effort. For information about Temperature@lert’s Cellular and SensorCloud offerings, visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.

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  • Tackling Walk-In Refrigerator and Freezer PMs - Part 1

    Now that you know what to look for and where, it’s time to get started.

    I recall my mom cleaning below and behind our home refrigerator cooling coils. She’d have a bottle brush, some rags, spray cleaner and the vacuum cleaner. It was a thankless and tiring job, especially since it needed to be done regularly. The first sign of the need for cleaning was soft ice cream, ice cream that normally would have been hard. The next was milk that spoiled more quickly than usual. Once I left home this task was left to me or my wife, a chore neither of us relish.

    Interestingly, cleaning was needed more in the winter than in the summer despite the fact the refrigerator was in a house without air conditioning and summer days were in the 80s and 90s. I believe this was because the house was more closed up in winter, we had more and bulkier clothing such as sweaters that shed fibers that make up dust, and the forced hot air system promoted the aggregation of fibers into dust bunnies. The need to change the furnace filter more in the winter as I’ve gotten older confirms my suspicion. Photos of home refrigerator cooling mechanicals covered with dust were shown in the second piece in this series; check there if you need a reminder.

    Before tackling the mechanical system maintenance a regular, thorough cleaning of the interior of the unit is recommended. This needs to be part of regular maintenance to insure the interior is not harboring germs that could spoil food or make people sick. Often a detergent and a sponge are all that is needed. The key is to move or remove all food items from the area to be cleaned so that walls and shelves are accessible and protect any food that will remain from cleaning products. Additionally this is the time to look over the food products to make sure they have not spoiled or exceeded the expiration date. And very importantly, food or packaging that is blocking fans needs to be moved to insure that all products inside the unit are receiving the chilled air.

    Another relatively easy DIY task is checking the door gasket integrity: looking for rips, tears or missing pieces. These gaps can let warm air in and cold air escape, endangering products stored near the gap while using more energy to overcome the leak.

    Figure 1. (Left) In the photo on the left a rip in the gasket can be seen. Replacing the gasket can be done by staff or a professional service, new gaskets obtained from the manufacturer. Link to Image

    In the previous piece we identified where to look for the two major components that require regular maintenance, the evaporator and condenser coils.  Evaporator coils bring the refrigerant to the inside of the unit to pick up heat.  The evaporator coils will be inside the cooled enclosure. They may be easy to access or difficult depending on their location, ease of access and whether tools are needed to remove covers.  Once they are located one can assess whether or not the job looks manageable or if professional services are needed.

    Evaporator Coil Maintenance

    The first thing to notice with evaporator coils is whether or not they are iced over. Many of us have seen this in older home freezers that don’t have automatic defrost cycles. Modern commercial units have defrost cycles but despite this frost can build up on the fan or on the coils due to frequent door opening, especially during warm, humid days. Again, a sign of evaporator coil icing is frozen items like ice cream do not freeze hard, or the unit is running continuously or nearly continuously to maintain temperature, and even then food products don’t seem as cold at they should be. Checking the internal temperature with a thermometer can help determine if the unit is not cool enough.

    Often icing is visible as in the image below where frost covers the fan guard or the coils themselves. In this case the unit will need to be defrosted. This means raising the temperature to melt the frost and may mean emptying the unit of food and storing it in another refrigerator or freezer while the defrost process is performed.

    Figure 2. (Left Image) Frost covering evaporator fan guard, and Figure 3. (Right Image) frost covering evaporator coils and fins.  These conditions reduce the cooling efficiency significantly and can lead to warmer than required temperatures, spoiled food, greater energy usage and even damage to the compressor from overheating to overcome the problem.

    Once frost is removed, or if no defrosting is needed, cleaning the coils and fan blades is performed. The coils will likely be covered with dust, dirt and grease, more or less depending on what is in the units and how much kitchen air containing cooking oils and greases comes into the cooler when the door is opened. Greases and oils from cooking can find their way onto every surface and the cooler the surface the more likely they are to condense onto it. This means the coils will need to be cleaned with a grease removing process. However, as in cleaning an air conditioning unit, it may be easy to damage the cooling fins, so caution needs to be taken in the process. Commercial products made for this purpose or even general kitchen cleaning products can work well. Since there are a lot of small gaps to clean, a spray or foaming spray can be very useful in making sure all surfaces are cleaned well. Commercial refrigerator maintenance services may use pressure cleaners or steam cleaning to do the job. In walk-in units a ladder may be needed to access the evaporator and remove the cover for cleaning.  A small, soft bristled brush like a paint brush may be useful to work cleaning products into tight areas; caution is required to prevent damage to delicate fins. Washing the cleaning product off the cooling coils can be done with water; caution needs to be taken to avoid water in the electrical components like fan motors, etc.

    Figure 4. Commercial refrigerator maintenance employing pressure cleaning to evaporator coils in a large commercial refrigerator. (Link to Image)

    The web is very useful to help understand the ins and outs of evaporator coil cleaning and maintenance.  Two video series may be useful. The first series is a short overview of before, during and after cleaning. There are few details about the process and the video quality is low but this YouTube series provides a good idea of what to look for in the process:

    Link to Before 

    Link to During 

    Link to After

    The second is much longer and more detailed, addressing total evaporator maintenance.

    Figure 5. Image from Video Series

    While long, this series gets into the details of unit disassembly, testing and reassembly.

    Link to Part 1

    Link to Part 2

    Link to Part 3

    Link to Part 4

    DIY evaporator coil preventive maintenance is within the capability of most operations. Special care and materials may be needed. The most important factor is time, whether or not the operation can set aside the time needed to perform thorough cleaning of the refrigerator box, perform gasket inspection and clean the evaporator coils thoroughly. Each organization will need to assess their skill level, staff time allotment and budget to determine if it is possible to perform this maintenance or use an outside service.  And this is only half of the task: In the next piece of this series we will address condenser coil maintenance. Once these two pieces are assessed a decision about DIY or professional services can be compared and a decision made.

    Temperature@lert provides cost-effective, fault-tolerant wireless temperature monitoring solution for organizations of all sizes. Our products and services can help bring a food processor, distributor, wholesale or retail outlet into compliance with minimal training or effort. For information about Temperature@lert’s Cellular and Sensor Cloud offerings, visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.

    Free Food Service Monitoring Guide

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  • Walk-In Refrigerator Preventive Maintenance Components & Checklist

    Commercial refrigerator maintenance begins with understanding your unit.

    The previous piece in this series looked at home refrigerator maintenance, something many if not all readers are familiar with and in fact may have done themselves. Now they own or are responsible for commercial units in their restaurants, cafés, sandwich shops, food trucks, or bistros. That unit comes with the blessings of cold air and fresh food and the curse of cleaning and maintenance. The message from the first piece in this series is that cleaning and preventive maintenance are needed and the consequences of not doing preventive maintenance can be demonstrated as seen in the first piece in this series. The cleaning and maintenance can be contracted out to commercial services as is done in many national chains, but small business owners may not have the budget for such services. So what can they do themselves?

    All refrigerators and freezers, commercial and home units, rely on fans, coils, and a compressor.  And they’re all charged with a refrigerant such as fluorinated hydrocarbons such as the family of Freons or newer mixtures of fluorinated hydrocarbons designed to address ozone depletion like R407A. 





    Figure 1. Refrigerator cooling system components showing evaporator and condenser assemblies as well as refrigerant flow. The Condenser Assembly including the Compressor is located outside the refrigerator, the Evaporator Assembly is located inside. Link to Image

    The refrigerant is a fluid that can convert from a liquid to a gas and back to a liquid as it is heated up and cooled during the refrigerator’s operating cycle and at temperatures inside the refrigerator (Evaporator Assembly) and inside the restaurant or outside the building (Condenser Assembly). Finding and identifying these systems is demonstrated below.

    Figure 2 (Left). Home refrigerator shows evaporator coils inside the unit. Liquid refrigerant “evaporates”, turns from a liquid to a gas and picks up heat from inside the cooled area. On the rear are condenser coils where the compressed gas, now a hot liquid can pass that heat into the ambient (kitchen air) and cool off. This cycle is repeated over and over to maintain the temperature at the set point inside the refrigerator and freezer compartments. (Link to Image)

    Figure 3 (Left). Evaporator coils are located inside the fan unit seen above walk-in door. The fan draws air over the evaporator coils so the refrigerant in the coils can pick up as much heat as possible during the cycle. (Link to Image)

    Figure 4 (Left). Commercial and walk-in condenser units can be located below the door as in a home unit, or somewhere in the vicinity of the refrigerator or freezer. Sometimes they sit on the roof of the walk-in, sometimes in an adjacent space or room.  The one shown here is removed to demonstrate the components which will be behind a cover. (Link to Image)

    Figure 5 (Left). This condenser unit sits along side the walk-in freezer in this outdoor installation. The fan is visible on the right of the unit. Air from the ambient is pushed into the enclosure to pick up and remove heat from the refrigerant inside the condenser coils, preparing it for the next pass into the freezer evaporator unit. (Link to Image)

    Back to the question, “What preventive maintenance and cleaning can commercial refrigerator and freezer owners do themselves?” The answer is quite a bit, but not everything. So let’s take a look at the tasks which are assembled from several websites listed below.

    1. Clean condenser coils

    2. Clean evaporator coils

    3. Clean fans and fan grills

    4. Check thermostat vs. actual thermometer

    5. Clean interior and door gaskets with mild detergent

    6. Clean drain lines

    7. Relocate items that block airflow inside or outside of unit

    8. Check door latch and gaskets are intact and working properly

    9. If needed, thaw ice from coils

    10. Listen to note any wobbles, rattles or other unusual noises during operation

    Below are links to commercial refrigerator maintenance lists in no particular order. Disclaimer: Temperature@lert is not endorsing these or any other companies or websites regarding commercial refrigerator or freezer preventive maintenance; links are provided as examples of what the industry offers.






    The next piece in this series will look at commercial units and the areas that require regular attention. Tips on what to tackle yourself and what requires professionals will also be offered.

    Temperature@ert provides cost-effective, fault-tolerant wireless temperature monitoring solution for organizations of all sizes. Our products and services can help bring a food processor, distributor, wholesale or retail outlet into compliance with minimal training or effort. For information about Temperature@lert’s Cellular and SensorCloud offerings, visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.

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  • New Sensor Cloud Feature: List View Filter & Search Tool

    Temperature@lert Sensor Cloud

    Here at Temperature@lert, we strive to improve your experience and exceed your needs. So we're excited to announce our latest feature: search & filter on Lists View. This tool allows you to search names and ID's of devices and sensors. It also will automatically save that filtered List View for future logins or until you change it. 

    Try a free online demo of Sensor Cloud now »

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  • Walk-In Refrigerator Preventive Maintenance: Where Do I Start?

    Good housekeeping is the key to proper maintenance.

    Some of us are old enough to remember a world before IT connected refrigerators and freezers. Heck, some of us remember ice boxes like the one in my grandparent’s lake house cottage when I was a tot. The iceman would come and deliver a huge block of ice that would melt, yielding it’s cold to the contents of the ice box. Milkmen made home deliveries then to, and just to set the record straight we’re talking trucks, not horse drawn wagons.

    Ice man delivering (Left Image) a large block of ice for ice box cooling compartment (Center Image) to keep perishable food cold (Right Image).

    I certainly remember home refrigerators before automatic defrost, nevermind sealed cooling coils. Every month or two, more in the summer, less in the winter, our parents would “defrost” the refrigerator.  This meant putting all the perishables in a cooler with ice and turning off the refrigerator and leaving the door open to thaw out the frost that not only covered the freezer surfaces but generally reduced the capacity by half or more, making its ability to keep ice cream hard and make ice cubes in less than 24 hours. Some images come to mind of the icebound freezer compartment that remind me of the four feet of snow outside our home after this year’s latest blizzard.


    1950s era freezer compartment (Left Image) and 1970s era freezer (Right Image) both required manual defrosting. Bowls of hot water sped up the process.

    And these old refrigerators required additional maintenance in the mechanical compartment at the bottom of the refrigerator and on the back side. Before today’s sealed units the compressor and cooling coils were exposed and often became wonderful collectors of dust, usually very quickly because the fan that draws air into the compartment and across the coils also sucked in any dust near the grills at the bottom of the unit. That dust can be a real problem when it coats the coils and compressor housing, insulating them from working optimally and making the compressor work much harder and increasing the chance it will overheat and fail, or at least not be able to keep the milk inside the unit within safe temperatures. Often the combination of iced up freezers and dust covered coils led to almost liquid ice cream on hot summer days.

    Dust covered heat exchanger coils and electronics at the bottom of a home refrigerator will significantly reduce efficiency and lead to higher electric bills as well as shorter compressor life.  Link to Images

    Compressor and associated plumbing covered with dust (left) and being cleaned (Right) during quarterly or half-yearly maintenance. Link to Images

    Many of us remember our mothers and fathers on the floor with the vacuum cleaner and possibly a long handled bottle brush cleaning the coils. And when we were old enough we were enlisted to take on this thankless task. The message here is that commercial and walk-in  frigerators and freezers require the same thankless tasks.  In fact because they are used harder, doors opening and closing many times per hour, and because the traffic in the area of the compressor and cooling coils may be higher than a household tracking in more dirt and dust, these commercial units are more likely to need regular attention than our home units.

    The good news is walk-in unit owners and managers can do a lot of the preventive maintenance themselves, certainly the type of tasks associated with home units.  And service companies can fill the gap if staff is busy. The real message is regardless of who does it, regular preventive maintenance is necessary and often pays for itself in reduced electric usage, lower food spoilage rates and reduced repair bills.

    The next piece in this series will look at commercial units and the areas that require regular attention. Tips on what to tackle yourself and what requires professionals will also be offered.

    Temperature@ert provides cost-effective, fault-tolerant wireless temperature monitoring solution for organizations of all sizes. Our products and services can help bring a food processor, distributor, wholesale or retail outlet into compliance with minimal training or effort. For information about Temperature@lert’s Cellular and SensorCloud offerings, visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.

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  • Have You Looked Behind Your Walk-In Refrigerator Lately?

    Commercial refrigerators and freezers are very reliable, but need love and caring too.

    You’re the proud owner of a restaurant, sandwich shop, pub, pizza parlor, you name it. Everything is running great. Then one day you find your walk-in refrigerator or freezer is not working. Maybe the power is out, maybe it became unplugged or tripped a breaker or fuse, or maybe something has malfunctioned and all of the food, beverages, etc. inside are warm and need to be thrown out. Beside the cost of the lost food, etc., there’s also the cost of the lost business as you scramble to replace the spoiled items and get running again, at least a day’s proceeds. And such events always happen at the worst times: Saturday or Sunday when crowds are expected for the big game or that special event or just to relax from a hard week.

    Those new to the business may not have experienced such occurrences. Those who have been around a while may have. Power outages occur, especially during bad weather. Breakers trip and plugs become dislodged. Doors are inadvertently left open. Fortunately many businesses have automatic temperature monitoring alarms for such occasions and except for power outages they are generally easily fixed: Reset the breaker, put the plug back in the outlet, or close the door. And because the alarm was sent before things got bad, nothing is lost.

    Figure 1: Wireless Z-Point temperature monitor inside walk-in refrigerator provides customers with email, phone and text alerts when things get too hot or cold. (Temperature@lert Photo)

    Like a power outage, a refrigerator malfunction is not so easily recoverable. If there is a temperature monitoring alarm device there may be time to save the contents. The malfunction may be due to failure of a minor part or loss of a major system, the compressor for example. For such events many restaurant owners need to call a professional. The challenge is to get one to make a call quickly before food becomes spoiled or inedible.

    The interesting thing is there are things to do to prevent or at least minimize refrigerator failures. Routine Preventative Maintenance is one. A commercial refrigeration maintenance company compared two Chicago area customers with a similar number of units, one with and one without scheduled maintenance and found an interesting result: Emergency and Non Emergency Service Calls and Compressor Failures were doubled for the customer without quarterly scheduled maintenance calls compared to one with quarterly scheduled maintenance calls over the course of one year (7/1/2012 to 6/30/2013).


    Total No. of Coolers & Freezers

    Scheduled Maintenance

    Non Emergency Service Calls

    Overtime Service Calls

    Compressor Failures

    Bar #1


    Every 3 Months




    Bar #2






    Table 1: Data from two similar customers from 7/1/2012 to 6/30/2013, one with and one without quarterly preventive maintenance service calls demonstrating a doubling in emergency and non emergency service calls as well as compressor failures when no scheduled maintenance is performed. ( Link to Source)

    Whether or not Bar #1 or Bar #2 paid more for the total service during this period is not disclosed, but one can imagine compressor failures and overtime calls cannot be cheap. My bet is Bar #1 did have a lower total cost especially since the cost of electricity when running poorly maintained compressors is higher.

    In this series we will explore the importance of regular scheduled maintenance for commercial walk-in refrigerators and freezers. Do it yourself as well as professional maintenance will be discussed and checklists provided to assist those new to the business as well as the long timers.

    Temperature@lert provides cost-effective, fault-tolerant wireless temperature monitoring solution for organizations of all sizes. Our products and services can help bring a food processor, distributor, wholesale or retail outlet into compliance with minimal training or effort. For information about Temperature@lert’s Cellular and Sensor Cloud offerings, visit our website at http://www.temperaturealert.com/ or call us at +1-866-524-3540.

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  • ALERT [Free White Paper]: Best Practices for Vaccine Temperature Sensor Placement

    With the US Center for Disease Control’s (CDC) Vaccine for Children (VFC) temperature monitoring requirements making their way into many pharmaceutical regulatory body requirements, many pharmacies and medical practices are contemplating purchasing automatic temperature monitoring devices such as data loggers and devices that provides real time data logging and alert messages or alarms when temperatures exceed specified ranges. And these devices can automatically generate digital temperature logs, graphs and reports compliant with regulatory requirements, replacing manual logs in some cases.

    So what happens if you don’t follow best practices? Sometimes not much, other times confusing data, and still other times potential problems. Take the case of a before and after installation. Initially a glycol vial buffered digital sensor was placed on the top shelf of a refrigerator near the cold air outlet (below). Temperature readings from Sensor Cloud show an average between 35°F and 36°F with lows approaching 30°F and highs near 42°F. The CDC’s VFC guidelines call for a range of 35°F to 46°F (2°C to 8°C). This installation is below the CDC minimum approximately 40% of the time. If the temperatures were any colder freezing of the vaccine is very likely.

    To continue reading the white paper, please download here:


    Best Practices for Temperature Sensor Placement in Vaccine Refrigerators & Freezers [Free White Paper]

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  • 2015 Temperature Sensors Forecast

    The sensor market is expected to grow to $6.05 Billion by 2020. With the demand of temperature sensors growing, it is important for the customer and manufacturer to choose their sensors wisely. From applications in the medical and healthcare sector to aerospace and defense, there is a rising need for more accurate temperature monitoring; thus creating an increased need to use proper sensors for industry specific applications.

    View the following guide to get a greater insight into the temperature sensor industry in 2015 and beyond:

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