The HDE PT150 is among the most efficient asphalt and thermoplastic heater in the world. At 87% efficiency you can expect a 40-50% reduction in propane use over other infrared systems. Our unique range of operating temperatures via adjusting gas pressure at the regulator, can better suit varying job and material conditions. The HDE PT150 is designed to be used as a 3' x 3' heater. The HDE PT150 has two separate heat zones 3' x 1.5' that can be independently operated and lit.