The VariMax IFRG is an ultra-high-efficiency, industrial, indirect-fired gas heater used to heat process air streams without contaminating the air with the products of combustion. The heater is useful for spray dryers and industrial processes with high temperature rises. The counterflow heat exchanger with hot side recirculation results in efficiencies of 90 percent+. Standard features include stainless steel heat exchanger, FM or IRI certified gas trains and complete heater controls. The heater is custom designed for each application with 1000°F max temperature rises and exit temperatures up to 1200°F.