SEP Series Commercial Unit HeatersProduct Features: Heating Capacities From 100,000 - 400,000 BTUH. Up To 80.5% Thermal Efficiency. Stainless Steel Heat Exchanger Is Available For Longer Product Life. Power Exhaust System with A Sealed Flue Collector Allows Conventional Vertical or Horizontal Venting To 35 Ft. Sidewall Venting Eliminates Roof Penetrations. Wiring Junction Box Is Located Outside Of Unit. Self-Diagnostic Board with Led Display Improves Troubleshooting Efficiency and Accuracy. Integrated Spot Nuts For Easy Installation Using Threaded Rod. Easy To Clean Tubular Heat Exchangers Made Of Aluminized Steel or Stainless Steel, Providing Resistance To Corrosion and Oxidation. Heat Exchangers Are Laboratory Life-Cycle Tested. Easy To Clean In-Shot Burners. Direct Drive Propeller Fans Are Dynamically Balanced For Quiet, Smooth Operation. Safe Direct Spark Ignition. No Standing Pilot Light.