Boilers, other than parts of machines, namely, hot water boilers; heat exchangers, other than parts of machines; steam boilers, other than parts of machines, namely, electrical boilers; steam generating installations; cooling installations for water; refrigerating apparatus and machines, namely, freezers; cooling installations for liquids, namely, liquid fuel media; water heaters; dampers, namely, control devices used in heating ducts to regulate the flow of air; heat accumulators; solar ther...