This article, written as a result of theoretical and practical research, describes a survey of condensate nucleation in heat exchangers utilizing low-potential heat of humid air. The authors conducted a series of studies aimed at developing energy-independent technical solutions to protect heat exchangers from the freezing of the moisture condensing on their exchange surfaces in the course of humid air heat recovery. There was a negative dependence of the thickness of the layer of condensate formed on the heat exchange surface, the condensation rate, and the moisture content of warm air. The article presents the outcomes of the numerical study aimed at building a model of the condensation processes that occur due to a flow of moist air when the air is cooled and heat is utilized. The study provided experimental validation for the consistency of the processes related to water vapor condensation in the flow of cooled moist air. The outcomes presented in the article can apply to both the exchange systems using the low potential heat of the atmospheric air, e.g., for room heating or snow melting, and to the exhaust air energy recovery systems of the building ventilation plant. (C) 2015 Elsevier B.V. All rights reserved.