GK water gas coolers are designed for CO₂ applications and can be used as:

• gas coolers in transcritical systems; 
• heat recovery heat exchangers; or 
• condensers in subcritical CO₂ systems. 

CO₂ flows on the tube side, while water or antifreeze mixtures flow on the shell side. The counterflow concept allows for small temperature margins between the two liquids and high performance in both transcritical and subcritical operation.