CPV code 42511100 designates Heat-exchange units in the Common Procurement Vocabulary (CPV 2008), the EU classification used to describe the subject of public contracts.
42511100 sits under 42511000 (Heat-exchange units and machinery for liquefying air or other gases) and groups 1 more specific sub-codes. When classifying a tender, choose the narrowest code that still covers the full subject of the contract.