Last June in Edinburgh, legionella contaminated many industrial cooling towers, used for several years to provide chilled water to service manufacturing processes. The potentially fatal disease infected more than 100 people. Adiabatic coolers provided by ICS Cool Energy Ltd are a safer alternative that eliminates the risk of legionella and save on costs and energy.
Adiabatic coolers consume 0.25% of the water in comparison to cooling towers, as well as having a third of the running costs. The coolers are designed to pulse as often as is necessary, greatly reducing water consumption and running costs. A UV system is supplied as standard which ensures the main water feed supplied to adiabatic coolers is clean, killing 99.99+% of legionella bacteria.
Adiabatic coolers rely on mechanical cooling which is supported by ‘free cooling’ for the majority of the year (97%), this means the adiabatic spray system is potentially only utilised for 3% of the year. A typical adiabatic cooler, cooling process water from 35°C down to 30°C in standard ambient conditions would expect to see an annual evaporative water consumption of around 56m3 per year with an additional 14m3 for regular purges.
An open circuit cooling tower relies solely on latent heat removal during the evaporation of water for its heat dissipation. The latent heat of evaporation of water is 2,260kj/kg, meaning for every kW of heat removed from the circulating water, 1.6kg of the spray water must be evaporated.
In addition, there is a necessity to bleed off a similar amount of water in order to avoid residual solids left in the cooling tower base tank clogging up the tower. Using the same example, this equates to an annual water usage of 27,955m3 which is a staggering 40,000% of the equivalent adiabatic cooler.
The difference in water consumption between adiabatic coolers and open circuit cooling towers is directly proportional to costs. A typical water cost is £2.30/m3 (water supply costs and a standard 95% sewage volume rate). The annual water cost for the adiabatic cooler would be £161.00 compared to £64,269.50 for the open circuit cooling tower.
As well as water costs there are the chemical dosing treatment fees, which would typically total £8,000.00, plus additional installation and commissioning, and on-going maintenance costs.  The capital cost of an adiabatic cooler and its first 25 years’ worth of water is still considerably less than just the first year of water consumption on the cooling tower.
The adiabatic coolers include inverter control and AC and EC fans which offer improved control, efficiency and noise reduction, and do not need to be registered with local authorities.
ICS offers financial packages to spread the costs of the adiabatic coolers and payback is usually within two years.
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