Energy efficient technologies and energy saving potential for cold rooms

Food processing demands a considerable and continuous energy supply and the rise in the price of electricity in South Africa has put much pressure on the industry. This has forced a re-think and development of alternative energy efficiency technology. In South Africa's cold storage chain the entire refrigeration system is among the most energy-intensive areas, but also offers opportunity for short and long term saving. It also provides an opportunity for enhancement of sustainable development and cold chain management. This paper presents a combination of three efficient technologies in those areas: (1) Airflow pattern optimisation through a computer assisted simulation model in which overall energy efficiency of cooling facilities is dependent not only on the energy generation efficiency of the refrigeration system, but also utilisation efficiency of all cooling facilities. Optimal airflow pattern of a cold room would move heat effectively to a refrigeration system, hence increasing both energy efficiency and refrigeration distribution. (2) Variable speed drive (VSDs) technology on evaporator fans motors: VSDs reduce motor electricity consumption by 30-60%; other benefits include prolonging equipment life through motor speed adjustments according to load. (3) Minimising heat transmission load by heat conduction transfer - coloured and shaded external walls being a major factor. Such technologies saved energy, thus reducing cold chain facilities' demand. The system was also cost-efficient and, inter-alia, research detailed in this paper contributed towards alleviating South Africa's energy problems.