Rupp Air Modular Direct Gas Fired Make Up Air Unit, Heated, 6500 CFM with 24” Mixed Flow Direct Drive Fan and 12" Burner Supply Fan - Natural Gas

Direct Gas-Fired Heated Make-Up Air Unit with 24" Mixed-Flow Direct Drive Fan

The Rupp Air R3D.500-24D is a heavy-duty direct gas-fired heated make-up air unit engineered to deliver high-volume tempered outdoor air for commercial and industrial ventilation systems. Powered by a 7.5 HP motor and a 24" direct-drive mixed-flow fan, this unit delivers up to 6,500 CFM and 503,388 BTU/h of direct-fired natural gas heating. Constructed from heavy-gauge G90 galvanized steel on a Size 3 housing platform, it is designed for down-discharge roof or pad installations requiring continuous, high-capacity ventilation.

Equipped for complete climate and system management, the R3D.500-24D features a remote space HMI touchscreen, factory-installed i500 series VFD (7.5 HP) for variable-air-volume (VAV) speed control, and an integrated total CFM monitoring package with a ±15 pressure transducer. The unit includes a self-adjusting burner profile with a 12" burner, motorized low-leakage backdraft damper with NFBUP-S actuator, sloped intake with washable 2" metal mesh filters, freezestat protection, field-wired exhaust contactor relay, and an insulated flat roof curb for complete turn-key operation.

Rupp Air Features & Benefits

• 24" Mixed-Flow Direct Drive Fan: Driven by a 7.5 HP 3-phase motor (6,500 CFM @ 0.500" wc ESP) to deliver high-capacity airflow without belt maintenance.
• Direct-Fired Natural Gas Heating: Provides 503,388 BTU/h of clean, near 100% efficient heat using a 12" burner assembly with an 80°F temperature rise capability.
• Fuel Type Flexibility: Factory-configured for natural gas operation, with liquid propane options available to accommodate site-specific fuel requirements.
• Remote Digital HMI & VFD Control: Features a remote space HMI touchscreen paired with a factory-mounted i500 series VFD (7.5 HP, 230V 3-Phase) for flexible VAV operation.
• Total CFM Monitoring: Pre-installed ±15 pressure transducer system with pneumatic tubing continuously monitors unit airflow performance.
• Sloped Filtered Intake: Weather-resistant sloped intake hood equipped with 2" MV EZ Kleen metal mesh filters for reliable pre-filtration.
• Heavy-Duty Enclosure & Size 3 Curb: Constructed with G90 heavy-gauge galvanized steel and supplied with a matching CRB35X84X16INS insulated flat roof curb.
• Comprehensive Safety & System Interlocks: Equipped with a motorized low-leakage backdraft damper (NFBUP-S actuator), freezestat protection, commercial smoke detector interlock, ship-loose 1" gas strainer, and a 23A exhaust contactor relay.

What's Included

Each Rupp Air R2D.250-20D package includes the direct gas-fired heated make-up air unit with a 20" mixed-flow direct drive fan, a sloped filtered intake with 2" MV EZ Kleen metal mesh filters, 0–150°F discharge temperature control with a remote space HMI, a DF2 gas manifold with dual pressure gauges and 1" butterfly modulating valve, low fire start, motorized low-leakage backdraft damper with LF120S actuator, damper proving relay, freezestat, commercial smoke detector interlock, exhaust fan start interlock relay, factory-mounted Lenze i500 series VFD with a VAV wiring package, total CFM monitoring system, down discharge construction, electrical cabinet LED lighting, and an insulated flat roof curb with full bottom curb corners.

Safety Features

• Redundant Gas Valves: Dual automatic safety shutoff valves protect the gas manifold.
• Timed Safety Lockout: Intermittent spark ignition system with timed lockout on ignition failure.
• High-Temperature Limit: Thermal limit switch monitors discharge air to prevent overheating.
• Airflow & Damper Proving: Airflow switch and damper proving relay verify proper air movement before firing.
• Freezestat Protection: Automatically shuts down airflow or signals controls to protect equipment from low intake temperatures.
• Smoke Detector Interlock Relay: Features pre-wired NO contacts for integration with commercial building fire alarm systems.
• Burner Observation Port: Integrated sight glass allows safe visual inspection of the burner flame.

Warranty Information

RuppAir provides a 2-year limited warranty covering defects in materials and workmanship under normal use and service. The warranty period is 24 months from the date of shipment. Defective parts covered by the warranty will be repaired or replaced at no charge after examination by RuppAir.

The warranty does not apply if the equipment is not installed by a qualified installer according to the manufacturer's installation instructions, is not installed in accordance with applicable federal, state, and local codes, is misused or neglected, is operated outside its published capacity, or the invoice is not paid according to the sales agreement. The buyer is responsible for all labor costs associated with warranty repairs or replacements. For complete warranty details, terms, conditions, exclusions, and limitations, please refer to the RuppAir Warranty Policy.