How to maintain refrigeration system efficiency

Simple maintenance tips that help keep your dairy refrigeration system running efficiently.

Once the system is in operation, looking after it will ensure that efficiency is maintained. Simple maintenance is often the best means of maintaining efficiency, and the following five top tips should help in keeping your system efficient:

1. Ensure that regular refrigerant level checks are carried out to ensure the volume of refrigerant is appropriate. Low levels of refrigerant will reduce the cooling effectiveness and require longer compressor on-times, leading to energy wastage.
2. Keep condenser coils clear, unobstructed, and free from dust and dirt. The condenser coils rely on fins to reject heat to the atmosphere: impeded airflow through the fins will reduce heat rejection and increase compressor running time until, at worst, continuous operation fails to cool adequately.
3. When system components require replacement, select an improved design. This specifically relates to compressors and valves. Older piston compressors should be replaced with more efficient scroll designs; fixed or thermostatic expansion valves should be replaced with variable pressure-controlled types.
4. Consider fitting Variable Speed Drives to condenser fans. Fixed speed fans will cycle on and off to maintain condenser temperature, causing step changes and stresses to the system. By operating fans constantly at lower speed matched to cooling demand, cycling is eliminated and fan power consumption and wear are reduced significantly.
5. Consider recovering the heat removed by the system and using it to pre-heat water for circulation cleaning. Whilst the main benefit is reduced water heating costs, this can also improve milk cooling efficiency to a small degree.