Initial Commercial HVAC installation cost almost always includes the pipes & ductwork. Pipes are installed in the walls and ceiling to distribute water or refrigerant depending on a type of cooling system that you have and a ductwork is needed for many systems to distribute cooled air throughout your space. So if you are replacing an existing HVAC system, and you don’t need to replace or redesign the existing piping and ducts, then your commercial HVAC installation cost will be much lower then initial installation.