With respect to industrial buildings, this study aims to clarify what would be the most efficient way of heating, considering at the same time its economic viability. Therefore, the study presents an integrated approach to heating and ventilation system to identify the most adequate of them in the case of an existing workshop. The object of the study is a solar heating system, with three auxiliary power options: an oil fuel boiler combined with a flue gas condensing unit, an electric boiler and a condensing gas boiler. The heating system is designed so that the primary energy only comes in on line when the solar energy contribution is not sufficient. The results of the study, from the point of economic viability as well as of energy efficiency and impact on carbon footprint, show that the natural gas condensing boilers with solar thermal installation and climatic separation from the outdoor though air curtains systems is the less contaminating and more efficient option in industrial buildings of the described type. (C) 2011 Elsevier B.V. All rights reserved.