Every cold store manager knows that, somewhat paradoxically, ice is the last thing you need in a freezer room. It clogs up the evaporators, makes the floor dangerous, and stops the mobiles from moving. But now there is another reason to ban ice from the freezer, it covers the racking, preventing proper rack inspections. It also can cause pallets to slip off the beams. Freezer store ice normally consists of moisture which is sucked into the room. At minus 25 ⁰C freezer rooms create a vacuum as the air volume decreases. Air flaps are supposed to prevent this pressure difference but are commonly frozen shut. Ice formation happens when the doors are left open and moist air enters the cold store. When the moist air encounters the steel and the floor, the water vapor in the air condenses to form water and then freezes to form ice. When the cold store door is opened, the warm moist air in the airlock is sucked into the store, depositing its moisture content as ice on the coldest immediate surfaces, normally the floor, insulated panels, and racking. Eventually, this ice will move(sublimation) to the coldest surface, being the evaporator fins, insulating them, making the refrigeration system work harder and driving up electricity costs. Moisture can also be introduced via leaking panel joints, malfunctioning drip trays, and, increasingly, accidental sprinkler discharges. Barri Malherbe, Barpro’s accredited rack inspector, isn’t happy with the amount of ice in South African freezer stores as it can make rack inspections extremely difficult. Please see the attached pictures. Slippery floors and ice-covered racking will lead to more rack damage, increasing the risk of collapses. The problem of cold store ice will never be completely solved while access doors exist. However, it can be minimized by installing well-planned airlocks. Pressure equalization flaps should be serviced regularly so that they work. This will prevent partial vacuums over weekends which can suck air through panel joints. As a minimum, freezer doors must be kept closed providing the door heater tapes are working and the rubber seals are intact. There are many door designs, fast-moving and otherwise, to assist in keeping moisture out of freezers, but these only work if properly maintained. For remaining floor ice and malfunctioning drip trays, Barpro has I-smelt, a non-corrosive white powder that does what its name says. Removing ice with gualas/crow bars isn’t recommended as they create floor cracks allowing moisture ingress which then widens cracks further. See the gallery of pictures of ice build-up discovered on his travels through South Africa. For more information contact: Barri-Leon Malherbe Accredited Rack Inspector & trainer– Reg: 0344 Mobile: 082 565 3970 Office: 021 5529190 training@barpro.co.za
