ESDU 84023 considers tubular condensers in which the coolant flows in horizontal tubes across which a pure vapour flows. It gives methods, derived empirically, for estimating total pressure drop (in two contributions, local pressure gradient across the tube bank as a function of quality, that is ratio of vapour mass flow rate to total mass flow rate, and nozzle pressure drop) and overall heat transfer (from the local shellside coefficient as a function of quality together with contributions from coolant, tube, and fouling). A step-by-step calculation procedure based on those methods shows how they may be used to check the adequacy of a design to meet a performance requirement, to design a condenser to meet thermal requirements and pressure drop limitations, to estimate the outlet conditions from a given condenser, or to evaluate test results on a condenser to determine, for example, its fouling resistance.