Articles from Cathy Goodwin CFSP at Linked in.

Choosing the right cold display is essential to the first impression of the consumer, but more importantly, the safety of your food. Just because a display has refrigeration, does not mean it will hold the food at the correct temperatures required to maintain food quality and safety. There are many types of refrigeration options, all with pro’s and con’s. And each stakeholder in the business has a requirement to meet.

The RDM wants “the look”. Sleek design, frameless, low profile, no vents in the joinery visible to the customers and so on.

The inspector wants “the food to be held within safe temperature zones”

The operator wants the “best price”

The consumer “buys with their eyes”

I want to use this article to try to explain, in layman terms, why it is so important to get expert advice on your display cabinet. What I have to say may be obvious to some people, useful to others and not as scientific as some may expect, but here goes!!

I visit the many shopping centres in Australia and abroad, I cannot help but look at all the refrigerated displays that are simply not fit for purpose or not stocked correctly, inadvertently causing unnecessary risk. Often the display is supplied by the shopfitter, as specified by the designer, who has followed a brief by the client. The display is built to suit the plans. The cabinet is a “one off” and built within a month or two. In essence, not a tried and tested system. The pro’s: it looks good and supplied within budget and the timeline required. The con’s: potentially higher than necessary energy consumption; spare parts may be difficult to source; limited access to do daily and periodical maintenance and service major or minor components; potentially condensation on glass, or most importantly, it simply is not an effective system to maintain the temperatures and satisfy the food standards legislation. Within a few years (or months or even sooner), the failings become obvious.

Understanding basic refrigeration principles will hopefully help to make the right decision for your specific needs and provide you with the necessary information to put forward to the RDM for flexibility with “the look” requirements.

Here is an example of a display that looks good, but not refrigerated.

Fundamentally, there is no such thing as cold, only the absence of heat. The working principle of refrigeration is very simple: it involves the removal of heat from an area and depositing it to another. All fridges have an evaporator, condenser, condenser fan, compressor, drain and some have an evaporator fan.

The evaporator removes the heat and the moisture forms ice on the fins or coils. If the fridge is static = no evaporator fan, if it is blown or ventilated = evaporator fan. All evaporators need to be defrosted, some manually and some have an automatic timer. While the fridge is in defrost, the internal temperature will probably rise because the fridge is in essence, off, no cause for alarm as the defrost period is usually only around 10 minutes. While in defrost the ice is melting off the fins and coils and water will drip into the drain hose. Some fridges have a drain hose that falls directly into the building drain, others have a tray that the water goes to, some trays have baffles to absorb the water, others need to be removed and manually emptied regularly and others have a heated element to boil off the water or the heat off the motor is utilised. If you are not familiar with refrigeration, this can all sound very complicated. Just remember, there will be water and whatever the water goes through (drain pipe or hose) and wherever the water goes to (pan or tray), will need to be kept clean and free from blockages.

Cold air does not rise and the energy from hot air will be absorbed by cold air. When you open the fridge door, you let the hot air into the fridge, when you open the door in your home on a cold night and the heater is on, the warm air escapes and so on.

To meet the criteria of the RDM or to create an unobstructed view of the food to the customer, custom built refrigerated displays are the ‘go to’ and cold plates are typically used with a single pane glass gantry or canopy. Here is an example of a cold plate display, you can see the product is elevated using plastic containers. this product is definitely not refrigerated correctly. But it looks good!!

In my opinion, a cold plate is a waste of your hard earned money unless you have a cross fin coil over the top. If you have a cross fin coil, you no longer have an unobstructed view. This type of refrigeration is common in butchers and seafood stores. Static cooling will not dry products out as quickly as blown or ventilated refrigerated displays. A cold plate is just like an ice skating rink. an evaporator runs under the base plate and removes the heat forming a layer of ice. The meat or seafood is displayed on trays on the freezing surface and the cross fin coil (another evaporator) above gently drops cold air onto the product maintaining the ideal temperature to display the food safely. Below is an example of a cold plate display with cross fin coil, hidden by advertising banners along the top of the glass. This display would be the best chance of holding the correct temperatures if the system has been serviced and maintained regularly.

This is an example of a serve over blown air display, these types of cabinets have a load line limit, the product to the left is clearly above the load line, effectively, not refrigerated when above the load line.

Here are two examples of a fully refrigerated and ventilated display. This type of display will definitely maintain a fairly consistent internal temperature, however, there are several factors to contribute to this success. The installation should have adequate ventilation for the heat off the motor and for the condenser to get cool air in. The internal air vents need to be kept clear, the doors must be kept closed (unless loading or unloading) and the product must be loaded at the temperature you want to hold it at – display cabinets are not designed to pull product down to temperature within the time frames required to meet the food safety standards. And finally, regular and ongoing service and maintenance.

Please feel free to comment or get in touch to discuss your specific display requirements any time. I can work with you to select the best display for your specific requirements and put you in touch with the right supplier for your needs.