There is no method of defining cold store capacity that satisfies the requirements of everyone concerned with cold storage. Storage capacity based on the weight of produce that can be stored will depend on the storage density of the products and the method of storage.
Therefore, unless only one product is stored under closely defined conditions, this definition is obviously unsuitable. It is generally agreed that it is more appropriate to define storage capacity in terms of the store volume but there are a number of ways in expressing this value.
Gross volume is the volume of the refrigerated space.
Net volume is the volume that can potentially be used for storage and is the gross volume less the volume required for coolers, structural requirements, doorways and other permanent features of the store.
Effective volume is the store space that can actually be utilised for storage and it takes into account the requirements for passageways, stacking equipment etc.
Gross volume and net volume can easily be defined by devising a simple set of rules for making these calculations. These store volumes, however, can only give a rough estimate of storage capacity and their main use may before statistical purposes. The effective volume can only be calculated for each particular case and to achieve any degree of accuracy, a drawing of the store layout would be required together with full details of the storage conditions. Store operators should therefore use general statements of store capacity with care and when placing an order they would give full details of the products and the storage operation to enable the supplier to provide a store to suit the operating requirements with the maximum utilisation of the gross storage volume.