In previous studies, we have measured the efficiency of natural gas flue-balanced space values of effective thermal efficiencies heaters, the most commonly used in Argentina. between 40% and 60% were found, and particular design characteristics have been identified. in the present work, we propose a variety of low-cost improvements that led to thermal efficiencies between 70% and 75%, which comply with international standards. The prototype is based on a commercial model in which thermal radiation and convection to the room living area are enhanced. if the improvements would be implemented, the savings in gas consumption for Argentina are estimated to be 3Gm(3) per year, with the corresponding savings in greenhouse gas emissions of 6 million tons Of CO2. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.