The Titan direct-fired (DF) propane heater system is designed for bed bugs and other pests. Each Titan DF treats from 750 to 1,800 sq. ft. with 500,000 BTU, offering many upgraded features not found in other models. The GTH-2500 package consists of two Titan DF heaters, four stackable axial fans, and four centrifugal high-temperature fans. It also includes a digital thermometer set, Mylar ducting, a fire suppression system, reflective insulating and a step-by-step comprehensive Heat Treatment Field Guide.