The traditional heating systems of commercial farms, usually composed of infrared light bulbs and furnaces, have shown to be inefficient for the satisfactory heating of broiler facilities (mainly in the south of Brazil), resulting in temperatures below the range of comfort of the birds. Thereby, this research aimed to eialuate the efficiency of heating systems more used in facilities located in the south of the Brazil, using the them1al comfort and air psychrometric conditions, as well as the influence of those factors in animal perfom1ance, fuel consumption and cost. The research was developed at nine commercial poultry facilities, where three derent heating systems (infrared light bulbs, furnace with indirect air heating, and radiant experimental system with supplemental heating of infrared light bulbs) were used. The more common indexes: weight gain, feed consumption, feed conversion, water consumption, and the factor production were used to evaluate animal performance. In the conditions of accomplishment of this experiment and for the obtained results, it was concluded that the three air heating systems studied behaved in different ways in relation to the amount of en ergy produced and consequent heating efficiency for the inside the facilities. The best results was found for the conjugated system with xperimemal radiant system + infrared light bulbs, followed by the furnace systems, and infrared light bulbs, in that order. None of the heating systems kept the birds in thermal comfort conditions during the whole period of the day.