SAFETY AND HYGIENE IN THE EVAPORATIVE COOLING SYSTEMS:
In order to prevent the growth of mould, fungus or legionella it is recommended to avoid:
- STAGNANT WATER
Upon the EKONAIR Evaporative Cooler being turned off the water tank is emptied via the purging valve. Whilst the unit is being inactive the water tank remains empty till the next start up. The water tank is constructed in such a way that it prevents the water from being stagnant (constant flow).
- HIGH WATER WORKING TEMPERATURE
The circulating water temperature in the Evaporative Cooler is near the air wet bulb temperature at the wetted pads. Its practical meaning is that in the temperate climate the circulating water temperature very rarely exceeds 23 °C even if the ambient air is as hot as 30 °C (which is reflected on the graph below). On infrequent occasions it can be of higher temperatures just for few hours a day. It is commonly believed that the Legionella start to reproduce in water of temperature exceeding 25OC, with optimal temperature of 30-38 °C. There is no such a threat in the Evaporative Coolers provided their proper installation and maintenance.
- CORROSION AND SCALING
In order to prevent corrosion all of the water contact elements in the Evaporative Cooler are made of plastic or non ferrous metals. The EKONAIR industrial Evaporative Coolers (models Breeze, Nortes, Ponente) are equipped with the programmable water tank purging function based on 4, 8, 12, 24 or 48 hour working period. The water tank is emptied completely in order to prevent scaling, remove the impurities (stopped on the cellulose pads and washed down to the tank) and prevent the water from exceeding the safe working temperature (heat pick up from ambient). The cellulose pads are impregnated by special salts as to resist their biodegradation (rotting). In other Evaporative Cooler models the water from the tank should be removed manually in adherence to maintenance rules.
The critical water carry over air velocity is assessed to be around 3 m/s. In the EKONAIR Evaporative Coolers the air velocity is kept at maximum 2 m/s. After passing through the cellulose pads the air contains only clean water vapour which excludes the danger of Legionella being present. It is assessed that there is about 20 millions of evaporative cooling systems in Western Europe. So far there is no hard evidence that any of the Legionellosis outbreaks was caused by the evaporative cooling systems.