What’s the difference between a water cooled chiller and air cooled chiller?


An air-cooled chiller has a condenser that is cooled by the environment air. The air-cooled chillers are preferred for small or medium installations but lately the quality improvement in their structure, allows the usage, in modular type, for large installations also. An air-cooled chiller is preferred especially in cases that there is not enough water or the water is very expensive. The water-cooled chillers have water cooled condenser connected with cooling tower and are usually preferred for medium and large installations where there is sufficiency of water. In addition, they are also preferred in cases that is demanded constant performance of the system, independently of the ambient temperature (industrial air conditioning, air conditioning of digital systems etc), because the capacity of the water-cooled chillers are not affected by the ambient temperature fluctuations.

A commonly asked question is what chiller is the best, air cooled or water cooled. The answer to that question is that there is no one perfect chiller for all applications. There are many aspects that come into effect when choosing what chiller would be best for a building and its cooling system.

Space is one of these issues. Air cooled chillers can utilize open space, such as a parking lot, roof or ground level area. Water cooled chillers are smaller in size, but require a mechanical room and cooling towers. On the flip side, air cooled chillers can have serious issues with recirculation if there are walls higher than the unit or too many units to close together. If there is a situation where outside walls are required for building code and the unit will not be receiving enough fresh air, then a water cooled application may be the best option.

Sound is another issue than may come into the equation. With any chiller sound is inevitable, air cooled chillers generally have a different decibel because of their fans. There are things that can be done to reduce the sound on chillers, but the best way to negate the sound is to purchase a quieter unit upon decision.

When it comes time to install a new chiller, these points should help in that field. There are many advantages and disadvantages to both kinds of chillers and some of those are listed below:

Air Cooled Advantages                                 

  • Install cost is generally lower
  • Less Maintenance depending on application
  • No need for a mechanical room
  • Cooling Tower not needed
  • Condenser pumps not required


Water Cooled Advantages

  • Usually have a longer life
  • Higher efficiency
  • Indoor placement
  • Larger tonnage capabilities
  • Refrigeration containment


Air Cooled Disadvantages

  • Generally less efficient
  • Life span is not as long
  • Usually have more operating noise


Water Cooled Disadvantages

  • Additional maintenance costs
  • Water treatment costs
  • Mechanical room needed