Modine's indoor duct furnace line was designed for use with a building's heating, heating/cooling and make-up air systems. Available in 11 model sizes, in both gravity (DFG) and power vented (DFP) configurations, the units cover a wide variety of applications. They have input ranges from 75,000 to 400,000 Btu/Hr and can operate on either natural or propane gas. The airflow direction can be specified when ordering the unit. The duct furnace is certified for location either upstream or downstream from cooling coils and has a drain pan that allows connection to a condensate drain line.