Indirect-fired heaters are typically installed outside a structure with ductwork drawing the heated air inside the facility. This heater type works similarly to a home furnace by forcing outside air through a heat exchanger and into the space while diverting products of combustion outside of the space through a chimney. The E5IDF series of indirect-fired heaters are recommended for cleanroom projects for pharmaceutical manufacturing, medical device manufacturing, and other construction/industrial applications where maintaining a controlled environment is crucial.