Vacuum Cooling explained.
With high demand on farmers to yield higher quality produce that will keep on supermarket shelves for longer periods, growers and distribution centres are looking for the best solutions to reduce wastage and lower operating costs. Vacuum cooling (VC) is a unique way of cooling. Instead of using (forced) cold air or cold water to cool down your produce, with vacuum you use “evaporative energy” for cooling. By reducing the pressure inside the vacuum room, you force (a fraction of) the product’s own moisture to evaporate. This evaporation costs energy, which is taken from the produce in the form of a temperature reduction.
What sort of fruit and vegetable is suitable for Vacuum Cooling?
VC is a pre-cooling method where the harvest removed field heat by reducing pressure inside a sealed container which evaporates moisture internally from the product. This process takes away energy which warrants rapid cooling, generally within 15 – 30 minutes for most products. VC works best for produce with a “high surface to weight” and that lose water easily such as lettuce and herbs:
Steps to vacuum Cooling:
- The product is placed in the vacuum cooler and the chamber is sealed
- The Vacuum pump starts working and decreases the air pressure in the chamber. The boiling point is consequently lowered.
- The boiling process requires heat, withdrawn from the product, allowing it to cool down.
- The Vacuum pump drain water-vapor through the condenser
- The cycle is finished, the produce is cooled and the pressure returns to 1000 millibar
- The condensed water is discharged and the cooling system is ready for the next load
Is it Expensive?
The fast and uniform cooling (the surface and core of the product reach exact the same temperature after VC) results in a substantially longer shelf life of produce and at the same time, saves on energy costs. The VC process is much more cost effective than other traditional cooling technologies as the output capacity, quick turnaround and energy cost reduction reduce overall operational spending. Many companies also offer rental solutions to appeal to seasonal growers.
Where can I get one?
Heuch Fresh offer a range of premium quality solutions for VC and cold chain management, using state-of-the art refrigeration technology and the latest environmentally friendly refrigerants. Together with a world-wide supplier network, they are leading in vacuum cooling technology and are able to supply full cold-chain solutions for cold and hot applications.