Experiments were performed to investigate the radiative heat emission of small scale hydrogen/airexplosions also impurified by minor amounts of inert particles and organic fuels. A volume of 1.5 dm3hydrogen was injected into ambient air as free-jet and ignited. In further experiments simultaneouslyinert Aerosil and combustible fuels were injected into the blasting hydrogen/air gas cloud. Fuels werea spray of a solvent (Dipropyleneglycol-methylether) and dispersed particles (milk powder). Thecombustion was observed with a DV camcorder, an IR camera and two different fast scanningspectrometers in NIR and IR range using a sampling rate of 100 spectra/s. The intensity calibratedspectra were analyzed using ICT-BaM code to evaluate emission temperature and intensity of H2O,CO2, CO, NO and soot emission. Using the same code combined with the experimental results totalheat emission of such explosions was estimated.