Steel and iron making industries have been driven by the requirements of maintaining or improving product quality and minimization of production costs. Within these requirements the overall energy management and energy efficiency play important role. Since the rotating-hearth furnace in the seamless pipe rolling mill has the nominal heating capacity of 27 t/h, and the real needs are of an average 13 t/h, the aim of the conducted study was to investigate whether it is possible by decreasing the height of rotating-hearth furnace workspace to reduce fuel consumption. In the article's introduction, a short description of the furnace with the measured values of heating regime, which served as the basis for calculations, is given. Namely, for the purposes of calculation is necessary along the furnace to know the temperatures of flue gases and the surfaces of linings and heated charge. The intensity of the charge heating depends on the radiation heat transfer from the flue gases and the linings onto the charge and the convection heat transfer from the flue gases onto the charge. It was established with the calculations to what extent the decrease in the furnace space height affects the coefficients of heat transfer by radiation and convection, and on the other hand, the heat loss through the furnace linings on the environment. In the end of the article, the suggested solutions are explained.Keywords: rotary hearth furnace, steel charge, heat transfer, furnace efficiency 1 Introduction During the last decades, global energy and market conditions have motivated energy users to improve energy utilization -this means reducing the fuel consumption -in order to remain competitive. For this reason, a research in the thermal processing industry has been directed toward one or more of the following: improving process productivity, improving thermal efficiency, increasing process temperature, improving process temperature uniformity, improving process quality and reducing the pollutant production [1][2][3][4][5][6][7][8]. The goal of a reheating furnace is to heat the steel charge to the minimum temperature consistent with achieving the correct temperature and metallurgical properties at the finishing stands of the mill. Uniformity of the temperature within the load, minimisation of local temperature gradients, avoidance of surface defects such as skid marks, overheating marks and oxidation scale represent the characteristics of the ideal product of the reheating operation [9][10][11][12][13][14]. The rotary-hearth furnace of the nominal heating capacity (throughput capacity) of 27 t/h is located before the rolling stand of type "pilger" in the line for seamless pipe production. Because of the lower production capacity of the seamless tube mill in the relation to the furnace heating capacity, the furnace works with the decreased furnace output of 13-15 t/h. For this reason, the preheated zone is not fired.