One can have only admiration for 3PLs who run cold stores because of all storage facilities a chilled or cold store is most likely to need the biggest investment and be more affected by standards and legislation, especially if a wide variety of food is stored which requires careful maintenance of different temperatures.
Moreover, such stores imply more safety problems and other risks, like the time when one 3PL had to write off £3m of melted frozen peas. It is, therefore, crucial to get the design right first time because the design and construction can affect profitability for many years to come.
Poorly designed buildings may suffer from problems such as roof space condensation if adequate openings and ventilation have not been provided. The building fabric and design should ensure that energy consumed in cooling the air is prevented from leaking through poor insulation and inappropriate doors. Good advice on cold store design and management can be had from organizations like UKWA.
Uppermost in cold store operators’ minds will be energy costs, which typically absorb 20-25% of total running costs so it is incumbent on operators to keep the store footprint as small as possible, and for this various forms of racking have been developed, including drive in/drive through, mobile and the latest forms of AS/RS systems. The racking types chosen will depend on each operators’ particular stored products’ dynamics. But one trend is obvious. As energy, land, labour and other operating costs rise management are increasingly looking to automation to control costs. Sometimes automation can cut space needs by up to 50% (crucial in the light of high cold store construction costs) , reduce energy consumption by 80% and labour by as much as 70%. It can also minimise accidents and the need for long-term staff exposure to sub-zero temperatures.
On the energy front, it is obvious that the more cold store doors are left open the more energy costs are compromised, not to mention dangerous build up of ice on floors and ceilings. An automated approach will solve that, especially when an air lock principle is used, because entry and exit of pallets involve small openings which are immediately sealed once each pallet passes through.
Palletisation in cold stores is another area ripe for automation, thanks to advances in robotics. Previously, robot limitations meant that products had to come out of the freezer area to be palletised and then return to the freezer. This meant the introduction of ambient air had to be cooled. The new robot developments are specifically designed for work in harsh environments so that palletising can be done inside the freezer without protective heating shrouds. This minimises ice build up on conveyors, etc, and cuts the time workers are exposed to sub zero temperatures.
If using electric forklifts inside the freezer areas it is important to remember that the cold significantly affects their efficiency. The average lift truck battery life cycle and rate of charge can decline by 25-50%, so a battery rated for 8 hr cycles in ambient temperatures may only last 4-6 hours in the cold. One solution is to use a higher voltage battery to improve run times.
Another challenge facing 3PLs, in particular, is that different products require different temperatures. In a cold store reconfiguring space is not so simple as it is in a conventional, ambient warehouse because to meet stringent food safety laws one has to take temperature into account. Where operators are running multiple temperature zones owing, for example, to a mix of products that change with the seasons, a modular curtain wall system is a flexible low risk option.
Other energy savings and safety tips include lighting. LEDs give off no heat like the more traditional lamps and so less cooling is needed and are far more cost effective owing partly to their greater longevity. When combined with motion-activated lighting they can cut energy demand by over 50%. For food hygiene reasons, timber pallets should be avoided inside cold stores but the point to watch if using plastic pallets is that they are more prone to slippage from racking beams so anti slip measures should be considered.