How to benefit from heat recovery

A look at the cost savings you can make by recovering and using the heat rejected during the milk cooling process.

All stages of milk cooling result in the rejection of heat in some form. Overall efficiency may be improved by recovering this heat and putting it to use, usually in an adjacent system which would otherwise consume electricity. Typically in a dairy parlour, this is for heating wash water.

As we have seen, heat is rejected at different temperatures. Pre-cooling water circuits are warmed from 12°C to about 23°C (based on the water flow rate being twice that of the milk, which is cooled by 22°C). That could represent a saving of 14% on the electricity used to heat wash water to 90°C. Refrigeration circuits can reject heat at 45-60°C, and this can be used to heat a stored volume of water to the same level, reducing the electrical input required to achieve final temperature by around 50%.

Any new facility should incorporate heat recovery as standard. It also makes sense to add heat recovery when a new compressor is installed, presenting the opportunity for the necessary hardware to be added to the condenser stage.