The hot water cooling system forms the basis of the cooling zone at the tunnel kiln and ensures fast, efficient and gentle cooling of the stoneware pipes. This system therefore offers enormous advantages over air-cooled systems in terms of system size, reject rate and further use of waste heat. The installed system works completely self-sufficient and fully automatic, it is now equipped with the latest visualization technology. The hot water cooling system installed at the tunnel kiln thus forms the waste heat recovery system for the further use of the heat gained for the adjacent tunnel dryer plants - thus no further primary energy requirement is required for the entire drying plant.