January 27, 2023

What’s the Difference Between CRAC and CRAH Units?

CRAC and CRAH units

If you work in construction, data centers, or HVAC systems, chances are you’ve heard of CRAC and CRAH units. But what exactly is the difference between them? Both types of cooling units are used to keep server rooms and other sensitive equipment operating at optimal temperatures and humidity. However, each type has unique features that make it better suited for specific applications than others. Let’s take a closer look at the differences between CRAC and CRAH units.


How CRAC Units Work 

CRAC units are self-contained air conditioners that use refrigerants and compressors to cool air. They are typically stand-alone systems that don’t require any additional ducts in order to function. The refrigerant within the unit is compressed using a compressor, which allows it to absorb heat from the ambient air within the space. This cooled air is then distributed to the source of the heat load. Another benefit of CRAC units is that they can be used in all applications due to their varied configurations. This unit is typically positioned opposite the hot aisle to cool data centers.

Advantages of CRAC Units:

  • Works well in small data centers that will not be scaling quickly 
  • Individual systems can provide backup cooling when needed 
  • Can operate in all outdoor weather temperature conditions

Disadvantages of CRAC Units:

  • Requires a large amount of power in bigger applications 
  • Not easily scaled for large expansion needs

How CRAH Units Work 

CRAH units use chilled water instead of refrigerants and compressors to regulate temperatures. These systems require piping—usually a network of chilled water pipes—in order to operate properly. The chilled water flows through coils located inside the unit which transfers heat from the interior space into the chilled water as it circulates through the system. This cooled air is then distributed to the heat load similar to CRAC units. Additionally, CRAH units can also be used with variable speed drives or control valves in order to provide more precise temperature regulation.  

Advantages of CRAH Units:

  • Easier to scale for large data centers and server farms 
  • Variable controls allow it to adjust to changing temperatures 
  • More cost efficient

Disadvantages of CRAH Units:

  • Requires a large amount of space 
  • More costly upfront

Contact Us Today!

Paramount Mechanical services Manassas, VA., Washington D.C., and surrounding areas with HVAC solutions tailored specifically to their customers’ needs; installing both CRAC and CRAH units when appropriate depending on application requirements. 

Whether your business needs an efficient chillers installation or multi-room cooling solutions – Paramount Mechanical has got you covered! With years of experience providing HVAC solutions across northern Virginia, our team can help you find exactly what you need for any project big or small! Reach out today for more information about how we can help your business!