Global Indirect Fired Heater Market Size, Share Demand Report By Product Type (Industrial, Commercial, Residential), By Fuel Type (Natural Gas, Diesel, LPG, Other Fuels), By Heat Output / Capacity (<500 kW, 500–2000 kW, >2000 kW), By End-Use Industry (Oil & Gas, Chemical & Petrochemical, Food & Beverage, Power Generation, Metals & Mining, Others), By Technology / Design (Direct-Fired Adapted, Modular & Skid-Mounted, Integrated Control Systems), By Region & Segment Forecasts, 2025–2030