Implication of installing mobiles on the size of the refrigeration plant

I was speaking to a potential customer yesterday who was adamant that installing mobiles in a freezer store instead of fixed selective racking and raising the storage capacity by at least 80% would necessarily increase the capital  cost  of the  refrigeration plant by a similar percentage.

I argued that while installing mobiles in a fruit store would influence the design of the refrigeration plant, the effect of mobiles on a freezer store system with unchanged room size should be minimal if the following applied.

  1. The freezer store continued to have one door.
  2. The frozen product arrived at minus 18 degrees Celsius and pallets did not sit for long periods in a warm airlock.

If mobiles were installed there would additional aisles and therefore more lights.

This additional heat load could be controlled by using LED fittings and automatic aisle light control on the Storax mobiles, turning the lights on only in the open access aisles. It is also true that an additional reach truck might be required. This would increase the number of movements into and out of the freezer and be an additional source of heat.

This conversation made me wonder how commercial refrigeration systems are designed for South African freezer stores. Is it on the basis of the doors being left open all day and with products being received at relatively warm temperatures? If freezer stores were designed on the basis of having airlock dehumidifiers and high speed doors, could the capital cost of the refrigeration system and the monthly energy costs be reduced? Would there be a further reduction if the docking bay design was upgraded to what was seen at Montague Cold Store’s new DC in Melbourne last year? What difference, if any, would there be to energy costs if freezer stores used pallet conveyors rather than moving stock into and out of freezer rooms via full sized doors?

Have refrigeration companies in South Africa investigated the savings that could be achieved if freezer stores were designed to incorporate these fairly standard features?

Montague Cold Store is currently using 1.3KWhrs per M3 of freezer volume per month. What are South African freezer stores designed to achieve given the ever increasing cost of electricity?

Read more about The Reduction of Energy Costs by the Dehumidification of Airlocks 2008  here

James Cunningham