Duct Air Heaters
Designed to Fit into the Processes’ Duct Work; Used Independently or as Part of a System
Our industrial direct gas-fired duct air heaters are completely packaged robust systems with air heat burners and controls.
Stelter & Brinck duct air heater models can be provided in horizontal or vertical orientation, and indoor or outdoor trim:
- Fresh Air Duct Section: for use on clean air streams, with or without preheat, and over 18% oxygen.
- Recirculating Duct Section: for use on dirty, hot or recirculated air streams.
- Selective Catalytic Reduction: low NOx systems, which can be a start-up or post-heater.
A low-emissions option is available for each of our industrial duct air heater models. These robust units are used independently or in conjunction with dryers, kilns, ovens, furnaces and other heat equipment. Applications include baking, curing, heat treating, printing and many more.
Industrial In-Duct Air Heater with Slate Controls
Duct Style Natural-Gas-Fired Air-Heater
Stainless Duct Air Heater
4 Duct Style Process Air Heaters, Tested-In-house
Duct Style Recirculating Process Heater
Duct Style Industrial Process Air Heater
Vertical Up-Fired Duct Air Heaters
FEATURES
Stelter & Brinck industrial duct air heaters are engineered for easy installation, user-friendly operation, and dependable performance. Each system is custom-built to your specifications and thoroughly tested to ensure reliable, efficient heat delivery.
Integrated Control Panel – Includes flame safety relay, first-out annunciator, relays and breakers, alarm horn, local start/stop push buttons, illuminated emergency stop button, indicator lights, FM-approved high-temperature limit, and a PID digital temperature controller (single or multi-loop). UL 508A certification available upon request.
Remote Control Interface – Fully compatible with PLC and DCS systems for seamless integration and process automation.
Custom Construction – Designed and built to meet FM, CE, GAP, NFPA, or CSA standards and your unique application requirements.
Certified Fabrication – All assemblies are welded by AWS D1.1, D1.3, and D1.6 certified welders for consistent, high-quality construction.
ADVANTAGES OF A STELTER & BRINCK DUCT AIR HEATER:
Backed by over 100 years of experience in industrial combustion systems, Stelter & Brinck duct air heaters deliver exceptional performance, efficiency, and reliability in direct fired air heating applications.
High turndown ratio- precise temperature control.
Fully proportional temperature control valve- smooth, responsive operation.
Multi-fuel capability – operates on natural gas, propane, or butane (other fuels available upon request).
Factory-tested and tuned- optimal performance prior to shipment.
Low-maintenance design- easy access to all major components.
Comprehensive service support– Stelter & Brinck’s expert combustion field service team provides start-up, tuning, and ongoing maintenance.
MODELS
FRESH AIR DUCT SECTION AIR HEATER (AHD)
Stelter & Brinck AHD Style Process Air Heaters are designed for direct insertion into process ductwork. Each unit’s burner utilizes the oxygen present in the process air stream, eliminating the need for a separate combustion air source.
Ideal for clean or fresh air applications, the AHD ensures reliable, efficient heat delivery.
Key Features:
Steel liner, fully insulated and enclosed with durable steel skinning
Flame observation sight port
Packaged fuel control and safety valve train
Single-point fuel connection for easy installation
Prewired to a numbered terminal strip for simplified setup
RECIRCULATING DUCT SECTION AIR HEATER (AHDR)
The AHDR Air Heater is built for recirculating industrial process air streams with low oxygen content. Designed for direct insertion into ductwork, this direct-fired, recirculating air heater includes a combustion blower for dependable performance in challenging air environments.
Capable of handling both high and low inlet and outlet temperatures, the AHDR offers flexibility and efficiency across a wide range of processes.
Key Features:
Dedicated combustion air inlet
Fully insulated, heavy-duty steel construction
High turndown burner for precise temperature control
Pre-piped and pre-wired fuel valve train
Packaged fuel control and safety system
Single-point fuel connection for easy integration
SELECTIVE CATALYTIC REDUCTION AIR HEATER (SCRAH)
The Stelter & Brinck Selective Catalytic Reduction (SCR) Air Heater is a low-NOx, direct-fired system designed to function as either a start-up air heater or a post-heater (reheater). SCR Air Heaters are commonly used with utility boilers, tail-end SCR configurations, and other systems where nitrogen oxides (NOx) are present but the flue gas temperature is below the level required for proper catalyst reaction.
SCR start-up heaters prevent low-temperature corrosion during boiler startup, while SCR reheaters (also known as Flue Gas Heaters or SCR Duct Burners) maintain catalyst efficiency during normal operation.
Key Features:
Operates using available oxygen in the flue gas or an external combustion air source
Provides consistent, reliable performance under demanding conditions
Fully packaged, pre-piped, and pre-wired for quick installation
Factory test-fired and tuned before shipment for guaranteed performance
