The paper deals with some of the results obtained during experimental research of the direct-contact condensation in cascade column. Downcommerless trays were used to obtain contact between water and steam in DN 300 column and experimental work included 198 runs at atmospheric pressure. Since no equation for the intensity of heat transfer was found in the open literature, original equation was established in the following form NTUL = f(F-LG) where NTUL is number of transfer units for liquid phase and F-LG is two phase kinetic energy parameter. (c) 2005 Elsevier Ltd. All rights reserved.