MISTING VIS-A-VIS HUMIDIFICATION

Misting has been around for a while and has had valuable uses in areas where moisture residue is a specific requirement, e.g. flowers on display is a fine example where moisture appearing on the petals certainly makes the purchase more tempting. Even some types of moisture ladened vegetables on display in a supermarket on an open stand would look far more attractive on the eye and hence customers will delve in and buy the fresh looking produce.

There are however occasions where high humidity levels are required but moisture unwelcome. Fresh produce, hanging meat & fruit (as an example) stored in an industrial or commercial cold chain, for one or more days, require constant high humidity levels to retain qualitative shelf life and prime condition but do not welcome any presence of dampness or wetness. Excess moisture in a cold chain would also be an ideal growing medium for moulds, bacteria, yeasts and spores to flourish.

Virtually all edible perishable produce is made up of 90% water and to maintain same in bulk storage (dry or cold), in prime condition, one needs to maintain a relative humidity level of between 90 and 95% without any presence of excess moisture. The only technology that can potentially provide that assurance is a dry fog or humidification system.

A dry fog system capable of maintaining humidity at 90 to 95% – 24/7 – without wetting the air or produce – is what would be required to keep perishable fresh produce in prime condition.

The only dry fog system that will guarantee the foregoing will have to be one that utilises atomisers that dispense water droplets at below 10 microns, coupled with an air pressure of not less than 6 bars. Also bear in mind that clogging could be an issue where pin-prick nozzles are being used in the atomiser, and together, with these continuous moving parts, high maintenance costs could become the order of the day.