One of the best ways to cool beer on a day out is to have a good time on the river, where the moisture makes the air cooler. The result is a rapid transfer of heat, and so the liquid in the bottle quickly matches the outside temperature.
Likewise, in industrial settings, air-water exchangers are a very good solution. This is especially true for situations complicated by an aggressive external environment or by the need to control clean air in facilities. Examples include chemical industries, cement plants, mines, foodstuffs, pharmaceutical, and so on.
When deciding to use an air-water exchanger, it is usually because the air temperature is too high, more than 40o C. Also, it could be that the quality of the air outside makes it impossible to work with ventilation, air conditioner or other solutions that need outside air for cooling. For instance, in the case of cement plants, filters are quickly blocked due to airborne particulates.
Paper mills, printing facilities or chemical plants are other examples of environmentally challenging, high-heat environments. Such facilities often do have an available temperature-controlled and stable supply of water. In such situations, an air-water exchanger is a good option that is low maintenance, since they require no filter.
The only prerequisite for installing one or more air-water exchangers is a source of cold water that can be filtered. It may come from a chiller or a well. But, in any case you must make sure that no sediment is present in the water which can reduce the effectiveness of the internal coils of the exchanger.
The main advantages of air-water exchangers are that they:
1) Are optimal for very aggressive and dusty environments.
2) Provide high water tightness of the thermal solution box.
3) Efficiently extract large amounts of heat.
4) Do not leave extracted heat in the cabinet or room. Instead, the heat is extracted outside the factory or installation, with the result being great energy savings for the end user against other thermal solutions.
To correctly select the air-water exchangers, it is essential to perform a thermal calculation involving how many calories must dissipate inside the cabinet. You also must know the working temperature of the water – in other words, temperature that the chiller will generate.
Also, it is recommended to use glycolated water of hydraulic properties similar to the one indicated in Table 1.
ProClima can help you select the most appropriate model according to the characteristics of the cabinet or installation. It contains the performance curves of the heat exchangers, and you can find the working point of the installation.