Evaporative cooling is a heat exchange between air and water, which causes a partial evaporation of the water and a consequent cooling of the air. Since the phenomenon occurs on the contact surface between these two elements, the efficiency of thermal exchange is greater the more the contact surface between them is.

A concrete example of the effects of this phenomenon is the cool breeze that we can feel along the banks of a stretch of water, where there is a continuous thermal exchange that lowers the air temperature.

With an evaporative cooling system, it is possible to recreate the conditions to maximize the natural thermal exchange between air and water and produce a significant fresh air flow to be introduced into the rooms to be cooled. Through a tailored designed duct system, it is possible to guarantee the conditions of maximum mixing of fluids and a targeted distribution of the air in the hot environments.

As regards to performance, the two systems are not comparable. A chiller makes thermal energy available in the form of water or refrigerant fluid at low temperature; the conditions of the external environment only partially affect the “quantity of cold which is produced”. However, to warranty a constant performance throughout the working range, as the outside temperature increases, the consumption of electricity increases exponentially.

On the contrary, the performance of an evaporative cooling system is directly related to the thermohygrometric conditions of the outside air. In this case, the energy consumption used remains constant and extremely low throughout the working range, while the “quantity of cold produced” can vary according to the climatic conditions.

An adiabatic cooling system is the ideal solution to reduce the sensible thermal load of medium-large sized environments. Even if, in certain situations it is not possible to achieve performance comparable to that of an air conditioning system with chiller, the benefit in terms of comfort is in any case significant and energy costs are definitely lower.

Since the energy requirement is very low, this system is the ideal compromise to allow maintaining conditions of thermohygrometric comfort in line with the needs of a production environment, throughout the summer season.

As written before, the system works thanks to the thermal exchange which happens between air and water. The air movement is achieved by using one or two fans that draw outside air, which in this way passes through the evaporative pads full of water and is convoyed to a ducted distribution system. The electrical requirement of the fans represents then the main consumption of the system. In fact, the fans mounted in EUCOLD coolers have specific fluid-dynamic properties and a multi-speed control system, further reducing the electrical absorption. The other elements such as pump, valves and ozone generator, result in a small consumption, that can be fewer in “free-cooling” mode (inactive suction pump).

Since the adiabatic process requires a partial evaporation of the water necessary to wet the EUCOLD pads, it is necessary to re-integrate it during the system operation. The quantity of water which evaporates is directly proportional to the elaborated air flow e to the temperature and humidity conditions of the sucked air; especially for this reason it is unrealistic to provide precise data.

Assuming a medium-heavy situation in which the incoming air has a temperature of 38 ° C and a relative humidity of 50%, it is estimated that about 30 liters / hour will be used for 10,000 m³ / h of processed air.

The system includes the installation of one or more cooling units outside the buildings, placed on the roof, on the wall or at ground level and a special air distribution system.

The system is completed by any extractors, gravity shutters or windows with controlled opening, useful for helping the expulsion of hot air.

For greater efficiency of the adiabatic cooling systems, it is necessary to create the conditions to facilitate the entry of fresh air and the simultaneous expulsion of the hot one. For this purpose, it is possible to use openings such as windows, doors and gates to improve the overall efficiency and also favor the cooling of the roof with consequent reduction of the radiated heat.

Sometimes it is necessary to use the system even during the night, when it is difficult, even impossible, to keep the doors open. In these cases it is advisable to install passive overpressure systems or special devices for forced air extraction.

This is not recommended! Reversing the rotation direction of the fans means to make them work in improper fluid dynamic conditions, a real pity! The blade profiles of EUCOLD fans, in fact, are the result of in-depth studies. Thanks to a high ratio between processed flow rate and absorbed electrical power, they ensure the highest performances among the market of coolers.

Moreover, dust and any polluting elements suspended in the internal air would come into contact with the cellulose of the evaporative packs, making them become the site of accumulation of dirt and drastically reducing their heat exchange capacity.

EUCOLD coolers are basically designed to be able to operate in a very simple way. Starting from a basic system using ON / OFF switches, it is possible to remotely manage the entire system through a centralized interface and the related wired network.

When the system is equipped with a centralized control system, the customer has the only task to configure the user interface with set-points and time slots of the weekly programming. However, through its network of Technical Assistance Centers, Carlieuklima is able to offer further customization for the management of the cleaning cycles of the evaporative panels, the timing of the tank water change and other parameters that modulate the use of water and optimize consumption, in reply to the needs of customers residing in areas where the water resource has significant costs.

The client can meet an agreement for the costs for the settings customization directly with the local Technical Assistance Center, trained and authorized by CARLIEUKLIMA for the commissioning of the systems and the carrying out of periodic maintenance operations.

Of course. When defining the most suitable system solution according to the needs of the client, the characteristics of the centralized management are an argument of the discussion as well. An integration of the EUCOLD coolers to an existing and / or higher hierarchy general management system is possible through the use of a gateway for MODBUS field protocol.

Absolutely yes. The performance of adiabatic cooling systems mostly depends on the thermohygrometric conditions of the outside air and in particular on the relative humidity of the air. A high level of humidity, in fact, limits the “quantity of heat” that can be removed through the air-water exchange. However, although the general opinion is that the relative humidity of the air during the daytime hours in summer is high, this is not always true: an increase in air temperature values always corresponds to a decrease in the relative humidity rate. You can have proof by observing the data provided by authoritative sources (i.e. CTI, that is the Italian Thermotechnical Committee) relating to the hourly weather conditions of our cities, which show that, on hot summer days, the relative humidity values are more than acceptable. The system therefore works in proper conditions.

On the rare days when the external humidity values remain high even during the day, it is clear how the performance of the system is limited and the temperature difference of “treated” air is only a few degrees respect to the ambient temperature. However, the contribution provided by the system in terms of perceived heat remains significant. In such extreme conditions, in fact, the lowering of the room temperature by a few degrees still brings obvious benefits in terms of comfort.

The situation is different during evenings and nights, when the humidity rate tends to increase. In such conditions, the system takes advantage on the mild temperatures of the external air, introducing it into the environment without the cooling it and therefore without the use of water (free-cooling mode).

In typical conditions of a building intended for industrial use, the adiabatic cooling system can supply into the environment big volumes of cooled air (10 ÷ 15 changes / hour). Taking into consideration the tolerances related to the diffusion of air in the environment, it is plausible to expect temperatures very close to those of inlet (see the performance table of the EUCOLD 530 units) in areas where there is a direct flow of treated air and slightly higher temperatures with lower relative humidity in the surrounding areas (also due to thermal load from machinery, lighting, etc.).

While sizing the cooling system, you must consider the hourly climatic data of the installation area, identifying plausible average working conditions and the consequent expected performances for the cooling units. At the same time, it is necessary to identify the thermal load that characterizes the rooms to be cooled, the determination of which is mainly due to solar radiation (through roofing, walls and transparent elements) and the endogenous component connected to the electrical power dissipated by the operating machines. At this point it is possible to evaluate the number of cooling units to be installed and the sizing of the air distribution system, also based on considerations relating to specific micro-localized conditions with the relative tolerances.

In winter season, when the internal temperature is higher than the external one, the distribution channels could convey the ambient air to the cooling units, causing a dispersion of heat. To avoid the creation of this flow, it is possible to use a special cover which, in addition to preclude the passage of air (in fact by sealing the passage), helps to protect the unit from atmospheric agents.

If it is necessary to use the system in winter as well (to ensure the minimum flow of fresh air), EUCOLD will continue to operate in ventilation only mode, with empty hydraulic circuit to prevent freezing of the water contained in it.

For a proper and complete maintenance, the cooling units must be cleaned at least once a year. In case of high hardness of the supply water, it is advisable to check the conditions of the evaporative panels more frequently to prevent the formation of limescale and therefore to maintain the effectiveness of air-water exchange.

In general, it is a good practice to plan the check to the units at least twice a year, on the occasion of the first seasonal start-up to remove the protective sheet and to put it out of service in winter and reposition the cover.

The system does not require the use of refrigerant and consequently no special license or certification is required by the maintenance technician.