In this article the authors present theoretical and experimental studies of gas-burning devices with the chordal feed of gas jets. The optimum diameter of the nozzles providing for the necessary range of gas jets for a high-quality mixing of fuel gas and air in the mixing chamber of minimum length is determined by calculation. The analysis of the parameters of the flame indirectly proves the reliability of the calculated data. The chordal flow of the gas jets and optimization of their range will significantly reduce the overall structural dimensions of the gas burner units. Short-flame gas-burning devices formed the basis for the creation of the Autonomous heat gun intended for repair and maintenance of engineering networks. Obtaining of a good heat gun is ensured by the motor fan capable of generating a high-pressure jet without connection to an external electrical network. Using of the autonomous heat gun in the housing and communal services is very promising in comparison with similar devices. (C) 2016 Published by Elsevier Ltd.