15 Specifying, designing and optimising refrigeration systems In specifying refrigeration equipment the function of the equipment must be absolutely clear. Refrigeration equipment is always used to control tem- perature. Either the meat passing through the process is to be maintained it its initial temperature, for example as in a refrigerated store or a packing operation, or the temperature of the meat is to be reduced, for example in a blast freezer. These two functions require very different equipment. If a room is to serve several functions then each function must be clearly iden- ified. The optimum conditions needed for that function must be evaluated and a clear compromise between the conflicting uses made. The result will inevitably be a room that does not perform any function completely effectively. There are three stages in obtaining a refrigeration plant. The first stage is determining the process specification, the second stage is drawing up the engineering specification, i.e. turning processing conditions into terms which a refrigeration engineer can understand, independent of the food process, and the third and final stage is the procurement of the plant 15.1 Process specification Poor design in existing chillers/freezers is due to a mismatch between what the room was originally designed to do and how it is actually used. The first task in designing such a plant is therefore the preparation of a clear speci- fication by the user of how the room will be used In preparing this speci fication the user should consult all parties concerned. These may be officials enforcing legislation, customers, other departments within the company and15 Specifying, designing and optimising refrigeration systems In specifying refrigeration equipment the function of the equipment must be absolutely clear. Refrigeration equipment is always used to control tem￾perature. Either the meat passing through the process is to be maintained at its initial temperature, for example as in a refrigerated store or a packing operation, or the temperature of the meat is to be reduced, for example in a blast freezer. These two functions require very different equipment. If a room is to serve several functions then each function must be clearly iden￾tified. The optimum conditions needed for that function must be evaluated and a clear compromise between the conflicting uses made. The result will inevitably be a room that does not perform any function completely effectively. There are three stages in obtaining a refrigeration plant. The first stage is determining the process specification, the second stage is drawing up the engineering specification, i.e. turning processing conditions into terms which a refrigeration engineer can understand, independent of the food process, and the third and final stage is the procurement of the plant. 15.1 Process specification Poor design in existing chillers/freezers is due to a mismatch between what the room was originally designed to do and how it is actually used. The first task in designing such a plant is therefore the preparation of a clear speci- fication by the user of how the room will be used. In preparing this speci- fication the user should consult all parties concerned.These may be officials enforcing legislation, customers, other departments within the company and