Replacement Dart Gasket Installation Instructions

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.

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

Dart Style Gasket Installation Instructions

1. 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.

Troubleshooting Defrost Problems

When troubleshooting walk-in freezers, technicians often find a frozen evaporator coil. Although there are several possible causes, one common cause involves the defrost system. For some reason, the system is not properly defrosting the evaporator’s coil on a regular basis. In order to effectively troubleshoot this problem, a technician must understand the design and operation of the defrost systems typically used.

One popular method of defrosting walk-in freezers is the electric defrost system. This is comprised of several components, including a defrost timer, resistive heater(s), defrost termination switch, fan cycling control, and drain line heater. An electric resistance heater is placed on the outer surface of the evaporator’s coils. The energized heater supplies enough heat to completely defrost the coils.

The resistive heaters used on a typical electric defrost system are sized to provide sufficient heat to effectively defrost the coil’s surface. Their capacity is normally rated in watts per foot. They are shaped to fit snugly onto the coil surface, creating efficient heat transfer during defrosts.

Most heaters are manufactured for a specific coil, and when replacing these heaters it is best to obtain the OEM replacement. Universal defrost heaters are available, but matching their wattage and shape may be difficult.

A defrost timer controls the entire defrost operation. It initiates the defrost cycle, controls the operation of the compressor and defrost heaters, and is part of the defrost termination. Defrost timers can be adjusted to initiate defrost from just once a day to several times a day.

The actual number of defrosts per day depends upon the location of the walk-in. Walk-in freezers are usually designed to defrost once or twice a day. The more humid and warm a location, the more defrosts will be needed. If a system needs to be defrosted more frequently, add only one additional defrost period at a time and monitor the results. Adding too many defrost periods will not be beneficial to the system or the customer.

In a common wiring diagram for a time-initiated, temperature-terminated electric defrost system the time motor (TM) is energized continuously. Normally closed contacts 2-4 of the defrost timer are wired in series with the compressor and the evaporator fan motor (EFM). Normally open contacts 1-3 are wired in series with the electric defrost heaters and the timer release solenoid (TRS).

The timer motor controls the operation of contacts 2-4 and 1-3. They work opposite each other. When contacts 2-4 are closed, 1-3 are opened. When contacts 2-4 are opened, 1-3 are closed. When the timer motor initiates a defrost, contacts 2-4 will open and 1-3 will close. This stops the compressor and the evaporator fan motor, and energizes the defrost heaters. Read the rest of this entry »

Refrigeration Guidelines for Specific Applications

This article is courtesy of Austin Industrial Refrigeration.

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 »

Anthony Transparent LCD Glass Doors with Video & Animation

Anthony, a manufacturer of commercial glass refrigerator and freezer doors, announced it will debut first-ever Transparent LCD Refrigerated Glass Doors at the 2011 NACS (National Association of Convenience Stores) tradeshow at McCormick Place in Chicago, IL.

Anthony debuted this innovative new product  with a 5 door display of Transparent LCD Refrigerated Glass Doors.

Read the rest of this entry »

Patton Named Regional Sales Manager

Mike Patton was named Regional Sales Manager for U.S. Cooler’s South Central Territory including the states of Texas, Oklahoma and New Mexico.

Mike comes to U.S. Cooler with over 17 years of experience in the industry. He has an extensive commercial foodservice equipment background as well as design work in the convenience and grocery store industry. U.S. Cooler is confident that his abundance of experience, knowledge of the industry, and work ethic will lend itself well toward serving their customer base.

Refrigeration History: Then and Now

–Philip J Reed, on behalf of Redstone College

Chances are you’ve recently pulled a soda or cold drink of water out of the fridge without giving it much thought. Maybe you dodged summer heat by heading to your air conditioned home. These refrigeration luxuries have done a great deal to change modern living, but avoiding a sweltering day or keeping food cool for consumption later hasn’t always been so easy.

Early Days

Jacob Perkins Refrigerator Photo: Xtimeline

Jacob Perkins created the “first practical refrigerating machine” in 1834, according to the Environmental Protection Agency, and the unit used ether in a vapor-compression cycle. A refrigeration machine in 1850 relied on water and sulfuric acid as a refrigerant, while still others in later years used ammonia, methyl chloride, sulfur dioxide, and other highly toxic, flammable substances. Needless to say, accidents with these machines were common.

And the refrigerators weren’t widely used. Even in the early 20th century, people usually had to get produce fresh daily and consume it almost as quickly. They made frequent trips to the butcher’s shop, and the milkman completed daily rounds. Fortunate people who had the money to spare for weekly ice deliveries were able to keep food for two or three days in an icebox.

Improvements

Fred W. Wolf created the first commercially successful electric home refrigerator, which was produced in the United States and went on sale in 1913. Wolf’s creation, dubbed the Domelre, was an air-cooled unit made for mounting on top of an ice box. In 1915, Alfred Mellowes worked in a backyard wash house to design another electric refrigeration unit, but this one differed in that a compressor sat in the bottom of the cabinet. Read the rest of this entry »

Hunt Named Regional Sales Manager

Darrell Hunt was named Regional Sales Manager for U.S. Cooler’s Mid-Central Territory including the states of Tennessee and Kentucky. Darrell comes to U.S. Cooler with over 35 years of experience in the industry. He has worked in manufacturing, walk-in installation, and sales developing himself as an expert in the industry. U.S. Cooler is confident that his abundance of experience, knowledge of the industry, and work ethic will lend itself well toward serving their customer base.

Give Your Walk-in a Walkthrough

Walk-in coolers and freezers: When is the last time you went into your property’s walk-in cooler unannounced? If you haven’t done it in a while, you might be surprised. I recently had the experience where an excellent GM asked me to identify opportunity areas in the kitchen operation. I went through the walk-in coolers and freezers and found the following issues within the first 10-minute visual inspection:

• 

  Make sure you have an inventory management process in place.

  Walk-in freezer that was very poorly lit (read: hard to find items), with boxes of frozen foods that had not been dated. Clearly without a date, it is hard to employ the First-in, First-out (FIFO) method of inventory management. How do we know when that box of chicken wings on the bottom of the stack came in? It is possible the box on the bottom is living there in perpetuity while new inventory is stacked on top every week?

• Food items stored unwrapped, with no date, in non-translucent storage pans and hotel pans. In one instance, two different products were in the same tray: one was uncooked raw chicken breast stored at an angle so the blood was running into unwrapped Canadian bacon. In a cruel moment of irony, just that morning I had been in the hotel’s restaurant outlet and sat next to four female business travelers who all ordered the eggs benedict for breakfast. When I eventually asked the sous chef (the executive chef was off at the time) what was going on, there was a general lack of awareness and training about the dangers of such poor food handling and the improper storage methods. The acts and non-acts were not malicious; rather it was a training and education issue. Oh, and he thought buying Lexans for storage purposes was too expensive for the GM to approve.
• Soup stored unwrapped in a large container sitting on the floor directly under the cooler’s condenser unit that was dripping water condensation into the soup. Read the rest of this entry »

Refrigeration and Freezing for Food Preservation

Because food is so important to survival, food preservation is one of the oldest technologies used by human beings. There are many different preservation techniques commonly used today, including:

• Refrigeration and freezing : Canning : Irradiation : Dehydration : Freeze-drying : Salting : Pickling : Pasteurizing : Fermentation : Carbonation : Cheese-making : Chemical preservation

The basic idea behind all forms of food preservation is either:

• To slow down or completely stop the activity of disease-causing bacteria
• To kill the bacteria altogether Read the rest of this entry »

New Jersey Steak House Goes Above and Beyond on Food Safety

When David Walzog got the go-ahead to design the kitchen for Strip House at The Westminster Hotel in Livingston, N.J., the executive chef’s wish list drew on his experiences working at the Monkey Bar and Michael Jordan’s The Steak House N.Y.C., both in New York City.

Walzog insisted on 14 sets of refrigerated drawers—where food is held below 40F—for mise en place. Several drawers were installed on the line, providing more space for plate assembly and enabling 14 cooks to keep surfaces clean and orderly.

Drawers and gaskets are cleaned daily, and twice a week they’re disassembled for bleaching. The quarry tile floor in the kitchen is graded and easy to hose down and power wash, he says.

Strip House’s five walk-in coolers are extra-spacious. The lowest shelf is 10 inches off the floor, two inches higher than health codes mandate, Walzog says, to facilitate mopping and cleaning. Rubber-coated shelving resists rust and cleans and moves easily to accommodate a variety of bin sizes. Safety glass and wire grating enclose two pairs of fluorescent bulbs for ceiling light. Read the rest of this entry »