A dry cooler is similar to an air cooled condensing unit, but utilizes a liquid solution, such as water, Ethylene Glycol/Water, or Propylene Glycol/Water, to transfer heat in lieu of refrigerant and compressors. These systems are often seen in Data Centers where excess heat needs to be removed, but certain low levels of humidity are not required. The water or solution absorbs heat from the space and transfers it outside to the dry cooler, which uses a series of condensing fans to perform its cooling.
A significant benefit of this type of system is that no liquid evaporation takes place, which eliminates the need for make-up water. Dry coolers can often reject larger amounts of heat in a much smaller footprint than traditional direct expansion air cooled condensing units, which can be a benefit for projects with limited ground or roof space.
Dry coolers are used in multiple buildings types and applications throughout the refrigeration industry, including the following:
- Data centers
- Office buildings
- Hospitals/medical office buildings
- Industrial/process systems
- Heat transfer/recuperation
- Power generation
- Induction cooling
Dry coolers can play a significant role in helping a building operate more efficiently. Though this equipment is not known for conserving energy, it can be utilized as a condensing unit for a heat recovery chiller. The primary function of a heat recovery chiller is to provide heating or chilled water from energy that is normally wasted, but it can also provide chilled water to supplement a building’s primary chilled water system in the event of a shut down or failure. When a heat recovery chiller supplements a chilled water system, there must be a system to remove excess heat. This is the perfect application for a dry cooler, which serves as a condensing unit or cooling tower. In certain applications, this type of design can eliminate the need for water or air cooled chillers to be connected to the building’s back up power supply, which can potentially reduce the size of an emergency generator.