Let us have a closer look at differences across types of air-cooled and water-cooled units. There are:
Outdoor air-cooled chiller with axial-flow fans
This type of refrigerating machine requires indoor installation. The cooling process of the condenser is carried out by means of axial-flow fans. There are two definite advantages of this type of cooling machines. They are the relatively low cost and the ability of using any free space for the installation such as roof area, free esplanade and etc. However some limitation is in the maintenance work on such units. They need seasonal water drain; the water or other liquid in has to run out of the evaporator, leaving it empty. The alternative to this procedure is the use of non-freezing solutions for example such as ethylene glycol or propylene glycol. Some brands can possibly offer cooling devices that are less noisy. Such changes as propeller speed reduction and propeller blade configuration can essentially decrease the sound-power level of the whole unit. These features can make this type of refrigerating machine more costly in comparison with another “noisy” unit of the same cooling power.
Indoors air- cooled chiller with axial-flow fans
This type of refrigerating machine requires indoor installation. Air intake for cooling the condenser is implemented by air ducts. Centrifugal fans are used to move the air. The first main advantage of this type is its “hidden” installation (no outdoor units) and the second one is that this type can operate year-round at any outside temperature. Disadvantages: However this cooling unit has drawbacks as well. It requires sizeable area to be placed in and supplementary ventilator costs.
This type of refrigerating machine requires indoor installation. Here intermediate heat-transfer material is used for cooling the device`s condenser, the heat-transfer agent is cooled in its turn in water-cooling towers or natural running water resources can also be used for this purpose. The latter feature makes this type of chillers ideal for industrial use in case the factory or whatever it is has a nearby body of running water. Water-cooled refrigerating machine can operate the whole year round due to its “free cooling”. In spite of the high cost, power-intensity and operation complexity this type of chillers can be the only possible solution for some industries.
Double-acting chillers (cooler/ heat pump)
Some models of air-cooled devices can be designed to operate in cooling mode as well as air-heating mode by means of the heat pump. This let use the system not only for cooling air in the buildings during summer period but also heat the air transition period.
Chillers with detachable condenser
This type of refrigerating machines as a rule is designed on the basis of chillers with water-cooled condenser. The unit itself is placed inside and is connected with the outdoor condenser where freon is used in the system. Moreover unlike water-cooled refrigerating devices this type of cooling units does not require the use of intermediate heat-transfer agent in the condenser, thus, there is no need to use power circulating pumps. However the distance between compressor-evaporating unit and condensing unit is limited. off line cooling system