The VariMax OTH line of standard indirect gas-fired heaters is over 80 percent thermally efficient and capable of a 150°F temperature rise with a 600°F maximum discharge temperature. The process flow can be once through or recirculated gas, and it comes with a complete set of standard options (including controls and FM or IRI gas trains). The VariMax OTH is provided as a stand-alone standard product, or it can be integrated into a fully packaged system with fans, dampers, filters and controls.munters_IN