ESDU 85022 guides the engineer in the process industries to the choice of the most suitable type of condenser for a specified duty, and assists the plant engineer in investigating reasons for inadequate performance or in estimating performance under changed conditions. The main characteristics of the types are outlined, together with their advantages and limitations. Causes of failure in operation are discussed. Flowcharts are provided to guide selection in the following cases: condensing steam exhausted under vacuum from a turbine; condensing vapour from an evaporator; condensing single and mixed process vapours; cooling a process gas which contains a vapour that condenses as it is cooled; condensing a vapour from a distillation column or reaction vessel ( a "reflux" condenser) returning the condensate; condensing a heat transfer fluid, for example in a refrigeration plant, a heat pump or an air conditioning plant. ESDU 84023 deals with the thermal and hydraulic design of a tubular condenser with downward flow over horizontal cooling tubes.