• Maintaining Your Walk-in Cooler or Freezer

    March 8th, 2013

    Whether you run a restaurant, convenience store or a supermarket, your walk-in is an important investment. It should be taken care of to ensure many years of efficient usage. Here are tips from walk-in manufacturer U.S. Cooler for maintaining your walk-in cooler or freezer.

    How to keep your walk-in operating efficiently:

    • torn gasket

      Torn gaskets can let warm air infiltrate the box.

      Close the door when not in use. Do not block or prop the door open for extended periods of time. Make sure it is closed at all times except when entering and exiting the walk-in.

    • Periodically (minimum of twice a year) clean the evaporator and condensing coil. If located outside, the coils should be cleaned more often.
    • Make sure fan motors are running at optimum speed.
    • Clean fan blades to reduce drag.
    • On outside condensing units, maintain clear and adequate airflow. For example, do not allow trash or weeds to accumulate around the walk-in.
    • Make sure there is nothing stacked around the coil to restrict airflow.
    • Occasionally have service technician check all electrical connections to make sure they are good and tight. Loose wires could cause high amperage, which will cause your unit to use more energy.
    • Check for damage or decay in the insulation on suction lines between condensing unit and evaporator coil. Replace as needed.
    • Hinges should be lubricated once a year to ensure the closes properly. (Some hinges utilize self-lubricating nylon cams, so this will not be necessary if that is the case.)
    • Make sure the lights are off when exiting the walk-in. Lights produce heat, which will cause your unit to run more to hold its optimal temperature. Make sure your walk-in has a switch with a pilot light so you can tell if the light is on without opening the door.
    • Do not pile anything on top of the walk-in. This could cause damage to the ceiling panels.
    • Check the door sweep for tears and make sure it is sealing properly against the threshold.
    • Periodically, check gaskets between panels to make sure they are not cracked or weathered. If so, check with your local health codes for the correct procedure to follow as far as repair and replacement. Read the rest of this entry »
  • Reduce Energy Costs in Your Walk-in

    November 26th, 2012

    Whether you own a restaurant, bar or convenience store, your walk-in cooler or freezer is likely one of the largest line items in your energy usage. If you’re looking to reduce your overhead it is imperative you do all you can to optimize your walk-in for maximum energy efficiency. In this article we’ll cover everything from maintaining your refrigeration system to energy saving accessories.

    Maintain your Walk-in

    door with icing

    Investigate icing around your door immediately

    Check your door sweep, door and panel gaskets for any rips, cracks or icing and replace if necessary.  Icing around the door could indicate a failure of the gasket, heater wire, or the door closer. Lubricate hinges twice a year to keep them closing smoothly. Make sure your walk-in is organized and covered items are clearly labeled to reduce the amount of time spent searching for ingredients.

    Maintain your Refrigeration

    Every six months, visually inspect your unit for corrosion, electrical issues, leaks or improper fan operation. Clean the evaporator coil and blades. Make sure the drainage system is clear of any debris. Ensure airflow to the unit is unobstructed.

    There are many more steps to take to make sure your refrigeration unit is running efficiently. Visit this page for more refrigeration maintenance tips.

    Upgrade Your Refrigeration System

    New Department of Energy standards went into effect in 2009. If your walk-in was manufactured before 2009, your refrigeration unit is likely less efficient than newer energy act compliant units. Read the rest of this entry »

  • Thermometers: Trust but Verify

    October 5th, 2012

    If the temperature in your walk-in cooler or freezer is not optimal for the type of products you are storing, it can lead to spoilage or the spreading of food borne illnesses. Thermometers are a very important indicator to tell if your walk-in is maintaining your desired holding temperature properly. However, thermometers don’t always give accurate readings, so it’s a good idea to verify that they are working correctly from time to time.

    When the thermometer for your walk-in cooler or freezer left the factory, it was calibrated to be accurate within one degree of the actual temperature. However, the thermometer may have been mishandled in transportation, or it may have lost its bearings over time; so it’s always a good precaution to test the reading against a known standard such as melting ice water. If the reading is incorrect, you will need to calibrate it.

    thermometer calibrationDial Thermometer Calibration

    1. Remove the lens to expose the pointer by un-threading counterclockwise (threaded lens) or by carefully prying (press-in lens) the lens away from the case using the molded slots.

    2. Fill a glass or insulated mug with crushed ice and add water. Stir the glass and let it sit for 5 minutes, until all the ice is melting into the water.

    3. Check the accuracy by inserting the temperature sensitive probe into the center of the cup of melting ice and water (32°F, 0°C). Keep it there for at least 30 seconds and take it out when the pointer has stopped moving. If your thermometer does not read 32°F, ± 2°F, continue onto step 4.

    4a. If the temperature reads high: Stabilize the pointer by placing a finger next to the left side of the wide end. Insert a screwdriver into the slot in the pointer hub and carefully turn the hub clockwise until the desired setting is reached.

    4b. If the temperature reads low: Stabilize the pointer by placing a finger next to the right side of the wide end. Insert a screwdriver into the slot in the pointer hub and carefully turn the hub counter-clockwise until the desired setting is reached.1

    Digital Thermometer Calibration

    digital thermometerYour digital thermometer should have a reset button or a recalibration screw. Read the rest of this entry »

  • Walk-In Cooler & Freezer Installation Tips

    September 25th, 2012

    All U.S. Cooler walk-ins are test assembled in our plant prior to shipment. This ensures problem free on-site installation. If you have had problems setting up your walk-ins, we have some tips that may be helpful.

    1. Receiving your walk-in: When your walk-in cooler or freezer is delivered by the freight company, it is critically important that you inventory the items delivered.

    packaged for shipping

    Most walk-ins are shipped “knocked down” or in stacks of panels.

    a. You must be sure when you sign the delivery receipt, you have received the freight in good condition and not damaged in anyway. The person signing the delivery receipt is responsible for inspecting the freight.
    b. If you see any damage to the container or boxes, this is a good sign that you may have hidden damage. If you have a camera, take pictures of any damage to your freight, even before it is taken off the truck. Call U.S. Cooler and ask for Customer Service if you see a problem with your shipment. When you call, have your order number available. The order number allows us to pull up all details needed to answer your questions.
    c. Insist that the driver does not leave until your satisfied all freight damage has been noted on the delivery receipt before the driver signs the delivery receipt.

    2. Take time to read the instruction manual and review drawing: Before you get started take out the installation instructions and drawing package. Inventory your parts against the drawing to be sure you understand the layout. If you have any questions on how to assemble the walk-in call U.S. Cooler or the manufacturer of your walk-in and ask for Customer Service.

    3. Make sure your area where the walk-in will be installed is flat: Level is critical when installing a walk-in cooler or freezer. Before installation you should get an exact tolerance of the entire space you are planning to install the walk-in. The longer the box, the more important it is to have a level area. Floorless boxes should be shimmed inside the vinyl screed to prevent gaps and air infiltration. A liquid leveling compound is very useful for floors that are not completely level. Read the rest of this entry »

  • Operating Costs for Walk-In Coolers and Freezers

    September 6th, 2012

    Before purchasing your walk-in, you may be wondering how much it will cost to operate your walk-in.

    Estimates for Standard Sized Walk-ins

    To give you a rough estimate of how much it cost to operate a walk-in cooler or freezer, using the national average of $0.1022 per kilowatt, look at the chart below.

    Cooler Average Cost per month Freezer Average Cost per month
    6×6 $67.50 6×6 $232.96
    6×8 $67.50 6×8 $232.96
    8×8 $120.70 8×8 $232.96
    8×10 $113.84 8×10 $355.24
    8×12 $113.84 8×12 $355.24
    10×10 $144.15 10×10 $355.24
    10×12 $144.15 10×12 $415.73
    Note: The above figures are estimates in a controlled environment; your exact numbers will vary.

    *These numbers were figured using the 12-month rolling average of $0.1022 kilowatt hour cost. According to the Energy Information Administration this is the average cost in the United States for commercial electricity.

    This chart was created using several assumptions that can affect your actual operating cost.

    1. The type of insulation in the walk-in.
    2. Efficiency of the refrigeration system.
    3. Inside and outside temperature of walk-in.
    4. Where the walk-in is located.
    5. The temperature and the weight of the product entering the walk-in.
    6. How often the door is opened.
    7. The age of the walk-in.
    8. Cost of electricity.

    This is just to name a few. If you would like to be more accurate using your electric rate, follow the instructions below. Read the rest of this entry »

  • EC Motor Start-up

    July 18th, 2012
    Interesting information about EC motors that could lead to an incorrect diagnosis.

    Electronically Commutated Motor AO SmitAs of January 1, 2009, all walk-in manufacturing companies must sell their refrigeration units with Electronically Commutated (EC) motors. EC motors lower energy costs and significantly improve the walk-in cooler or freezer performance. These energy efficient motors are offered as a complete unit or as a drop-in replacement. Whichever your use is, if you are not familiar with the EC motor it may seem odd when you initially start it up.
    When starting an EC motor, the motor must know where the rotor is located in order to start and continue to run. When power is first applied to the motor, the controller will apply a gradually increasing amount of current to all three windings in the motor over a period of 2 seconds. This will cause the rotor to move to a known location. This move will range from no movement at all if the rotor has stopped in the location needed for the next start or may be a much larger movement if it was a longer distance  from where it needed to be. With a fan blade attached, it may even overshoot and move backwards to get to the right location. After that 2 second “positioning” period the controller will start applying power to different phases in a slow rotating pattern that increases in speed over the next 2 seconds until the rotor is moving fast enough for the controller to be able to detect its location. This second phase of the start cycle usually happens so quickly that you cannot really see what is happening. Within 3 to 5 seconds of applying power, the motor should appear to be running normally, but during those first 2 seconds the movements may seem as though the unit is having troubles starting or is broken.

  • Replacement Dart Gasket Installation Instructions

    January 24th, 2012
    walkin freezer dart gasket

    Magnetic dart style gasket

    There are various mounting styles of gaskets used in manufacturing walk-in coolers and freezers. Some are secured with screws, stapled onto a flat surface, or cemented into a channel. U.S. Cooler chooses to use magnetic dart style gaskets that push into a groove.
    The causes of gasket failure are numerous, from loss of vinyl elasticity over many years to an employee ripping the gasket by running into it with a cart. If your gasket is building up ice or condensation, that’s a sign that your seal is not tight and you need a replacement gasket.

    Installing replacement gaskets correctly is important to ensure a tight seal with no air infiltration or icing along the door frame.

    Dart Style Gasket Installation Instructions

    1. door gasket drawing

      Soak the gasket in warm water for several minutes in increase pliability.

      Remove door from walk-in cooler/freezer (some hinges have lift-off capability when the door is open) and place on a pair of saw horses or table with gasket side up. Using a screw driver, remove the 7 screws from the inside edge of the old gasket if they were installed. (NOTE: some types of gaskets are not screwed in).

    2.  After old gasket has been removed place new door gasket around door, laying it out across the top and down the sides of the door. With door gasket in position around the door starting at the top corner, firmly seat the spur of the door gasket into the groove of the extrusion along the edge of the door using a hammer. It’s important that the spur be positioned over the groove correctly as it needs to be seated on the first impact of the hammer. Continue along the top of the door seating the gasket and then down the sides until you get to the bottom of the door.
    3. Trim the bottom of the door gasket so it just covers the metal strip of the door sweep. It should not extend onto the rubber part of the door sweep. If the gasket is trimmed, remove the rubber plug from the trimmed piece and insert it into the bottom of the gasket to keep the magnets in place. Use NSF approved silicone caulk to keep the rubber plug in place.
    4. Using a screw driver, install 7 screws into the locations shown on this drawing.
    5. Re-install door onto the hinge blocks on the walk-in frame and check door for proper operation.

    You can buy name-brand walk-in parts such as gaskets, handles, and door closers from walkincoolerparts.com. Walk-in Cooler & Freezer Parts has the lowest prices on the net and will ship most orders the same or next business day.

  • Refrigeration Guidelines for Specific Applications

    December 27th, 2011

    This article is courtesy of Austin Industrial Refrigeration.

    floral storage refrigerator

    Flowers do best with High Humidity and Low Velocity refrigeration

    Aside from the box temperature, other considerations that are particular to medium temperature applications (walk-in coolers & refrigerators) are the air velocity and humidity of the refrigerated space. Below freezing, humidity is inherent (the moisture is mostly frozen out of the air), so low temp applications are easier to spec than medium temp.

    The following are common design parameters and examples of their application:

    • 35 degrees F / 90%+ relative humidity (low velocity coils) – high humidity – Used for: sensitive materials, floral – roses
    • 35 degrees F / 85% – 90% relative humidity – general purpose – Used for: foodservice, fresh meats, packaged goods not sensitive to humidity, short-term mixed produce, thawing, and dry goods unaffected by humidity
    • 35 degrees F / 60% – 75% humidity – low humidity – Used for: retail, beer and beverage coolers, packaged items, materials sensitive to humidity
    •  45 degrees F / 55% – 70% humidity – low humidity – Used for: aging red wine
    • 45 degrees F / 90%+ humidity (low velocity coils) -high humidity – Used for: sensitive materials, floral – general
    • 55 degrees F / 55% – 70% humidity – low humidity – Used for: processing rooms occupied by personnel
    • 55 degrees F / 60% – 75% humidity (low velocity coils) – low humidity – Used for: produce Read the rest of this entry »