Frequently asked questions about cooling technologies
What is the difference between evaporative and adiabatic cooling? In which cases should you choose an open- or closed-loop cooling tower? What is subcooling? A continuously updated section to answer frequently asked questions in the industrial and civil fields.
È possibile ottenere la massima efficienza energetica attraverso una serie di accorgimenti: ad esempio, dimensionando un sistema di raffreddamento in base alle esatte necessità di raffreddamento, o poco sovra-dimensionato.
Read all FaqPerformance depends primarily on air temperature, relative humidity, and wet-bulb temperature, which represents the theoretical cooling limit that can be achieved. Altitude, thermal variations throughout the year, and surrounding obstructions also affect efficiency.
Read all FaqChoosing the best industrial cooling system depends on several factors. Among them: the required cooling capacity.
Read all FaqThe required cooling capacity, and the consequent sizing of the cooling system, can be calculated by an engineer experienced in industrial cooling.
Read all FaqThe approach to the wet-bulb temperature is the difference between the leaving water temperature (or water–glycol mixture) and the air’s wet-bulb temperature. The smaller this difference, the higher the cooling tower’s efficiency.
Read all FaqThis is not something to worry about: the cooling consultant knows the right questions to ask for the selection of the best cooler, supported also by advanced software for calculation, selection, and resource optimization.
Read all FaqYes, there are calculation and sizing software: some manufacturers and cooling consultants use them in recent years to make a selection that is as tailored as possible to the needs of the individual project.
Read all FaqSelection software makes it possible to simulate thermal loads, climatic conditions, and design variables in order to determine the optimal configuration of cooling towers, dry coolers, or chillers. They provide comparative analyses of capacity, energy consumption, noise levels, and operating costs. The goal is to ensure the right balance between performance, energy efficiency, and operating expenses.
Read all FaqPre-order consultation with an industrial cooling expert is often free of charge: consultant and customer can then jointly evaluate the selection of a cooler, based on specific project needs.
Read all FaqEach type of industrial chiller has its own distinctive characteristics. In general, air cooling has lower efficiencies than other systems, especially in warmer seasons. In contrast, evaporative systems (wet cooling towers and evaporative gas condensers) have higher efficiencies.
Read all FaqThere are several types of industrial cooling systems. These include: cooling towers and adiabatic coolers.
Read all FaqAll evaporative cooling systems use the evaporation of a small amount of water to lower the temperature of the larger mass of water. There are three main types of evaporative cooling systems: open circuit cooling towers, closed circuit cooling towers, and evaporative condensers.
Read all FaqUn sistema di raffreddamento adiabatico (dry cooler adiabatico per liquidi, condensatore adiabatico per gas) è un sistema che combina il principio di un dry cooler (raffreddatore a secco) con il pre-raffreddamento adiabatico dell’aria esterna.
Read all FaqAmbient air is the heat-transfer medium that enables water evaporation and thermal exchange. Its temperature and relative humidity determine the efficiency of the process: under dry-air conditions, the evaporative effect is at its maximum.
Read all FaqEvaporative and adiabatic cooling both take advantage of air to lower the temperature of a process fluid (water, water and glycol, gas).
Read all FaqBoth systems use water, but in different amounts, in different ways, and with different levels of efficiency. The direct evaporative
Read all FaqThe structure and components of the two systems are, of course, a consequence of the two different operating principles.
Read all FaqAdiabatic cooling systems (adiabatic dry coolers for liquids, adiabatic condensers for gases) are the optimal solution where the goal is to save water, either due to the absence of that resource or to risks associated with its management.
Read all FaqIn summary: high cooling efficiency, low operating costs, and others related to the operation of the technology.
Read all FaqModern evaporative coolers use automatic blowdown systems controlled by conductivity sensors, partial recovery of discharge water, and optimized make-up strategies. Adiabatic systems, on the other hand—with the proper use of sensors and PLC-based parameter settings—use water only during periods of maximum thermal load, reducing overall consumption compared to traditional cooling towers (though with some loss of efficiency). The adoption of recovery circuits also allows part of the water to be reused in any cooling system that relies on this resource.
Read all FaqChoosing the system best suited to your needs depends on several factors, mainly related to the specifics of the individual plant project to be developed: an exchange of information with a cooling consultant is often helpful.
Read all FaqWherever there is a process fluid to be cooled, up to a temperature of a few degrees above the wet bulb temperature of air, an evaporative cooling system can be used.
Read all FaqIn an evaporative system, approximately 2% of the mass to be cooled evaporates and is released back into the environment.
Read all FaqSome main advantages can be enumerated, related to reduced water use and optimized operation during different seasons and times of the day.
Read all FaqThe difference between the two systems lies in the different type of circuit exploited for cooling the process fluid.
Read all FaqIn direct evaporative cooling (open-circuit evaporative tower), the process water to be cooled is introduced into the tower and comes into direct contact with the outside air. The water evaporates directly into the air, removing heat and lowering its temperature — leveraging a simple natural principle: the forced evaporation of a small amount of water causes a temperature drop in the main water mass.
Read all FaqBoth open-circuit and closed-circuit towers exploit a very efficient operating principle: forced evaporation of a minimum amount of water causes a lowering of the temperature of the main water mass.
Read all FaqIn summary: Low installation and maintenance costs and very high cooling efficiency.
Read all FaqAmong in main advantages: no contamination of the primary circuit and reduced risk of freezing by being able to insert ethylene glycol into the circuit, for example.
Read all FaqYes, it is possible in the case of closed-circuit evaporative cooling towers.
Read all FaqThey vary according to type, capacity, and specific characteristics: from a few thousand euros to hundreds of thousands.
Read all FaqLes condenseurs évaporatifs fonctionnent de la même manière que les tours de refroidissement en circuit fermé. La seule différence réside dans le fluide de traitement, qui est un gaz réfrigérant.
Read all FaqSafety is based on proper design, periodic maintenance, and effective water control. It is essential to prevent stagnation, ensure proper drainage, and maintain easy access to components for regular inspections.
Read all FaqCooling water tends to concentrate salts and impurities, which can lead to scaling and corrosion. Prevention involves properly calibrated chemical treatments and automatic blowdown systems managed by conductivity sensors.
Read all FaqManaging the risk of Legionella in cooling towers requires an integrated approach based on system assessment, proper positioning, water treatment, prevention, and continuous monitoring.
Read all FaqBiological growth—such as algae and bacteria—is promoted by warm, stagnant water. Prevention relies on proper chemical treatment, controlled blowdown, and constant recirculation.
Read all FaqBased on the partially different operating principle, there are some common and some peculiar components of the two types of evaporative cooling systems.
Read all FaqVariable-speed fans, controlled by inverters, adjust the airflow according to the thermal load.
Read all FaqThe longevity of a cooling tower—or any other heat-rejection system—depends on the materials used and the operating conditions. Fiberglass (FRP) structures are now the standard for corrosion resistance and lightness in cooling systems, especially evaporative towers.
Read all FaqFiberglass cooling towers offer an efficient and highly durable solution for managing industrial heat, thanks to the unique properties of the material.
Read all FaqIn sensitive locations, acoustic barriers and modular silencers are commonly adopted. Noise reduction in a cooling system involves three main areas: aerodynamics, components, and layout.
Read all FaqAn evaporative condenser condenses the refrigerant gas inside coils that are wetted by sprayed water and cooled by an airflow. According to the evaporative cooling principle, when a small portion of water evaporates, heat is dissipated and the refrigerant condenses.
Read all FaqFree cooling uses outside air to cool the process fluid without relying on the refrigeration compressor.
Read all FaqSubcooling is the reduction of the temperature of the refrigerant leaving the condenser.
Read all FaqSubcooling results in an increase in the cooling capacity of the system, hence electrical savings and a higher COP (coefficient of performance).
Read all FaqAlchemist is a patented solution from MITA Cooling Technologies that combines the useful effect of subcooling with the natural and efficient operating principle of an adiabatic cooler in a single device.
Read all FaqA fan draws in a portion of air from the outside environment and then runs it through a finned coil inside which circulates the refrigerant to be subcooled.
Read all FaqAlchemist can be used with any type of refrigerant.
Read all FaqThe thermophysical characteristics of R744 make this refrigerant perfect for subcooling.
Read all FaqAn adiabatic gas cooler must adiabatically cool the entire air flow rate of the gas cooler itself, Alchemist works only on the subcooling air flow rate.
Read all FaqDownstream of a gas cooler in R744 systems, we have several references in commercial refrigeration, or combined with a refrigeration unit.
Read all FaqAlchemist is designed to bring efficiency to the system, which is why it does not require frequent or special maintenance operations.
Read all FaqAvailability of mains water and a discharge point, an electrical connection, and a junction between the Alchemist coil and the refrigerant line.
Read all FaqCertainly. The subcooler is an environmentally sustainable solution because it provides an efficiency "boost" with each installation (COP increase).
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