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Additional Resources

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Frequently Asked Questions View all FAQs
How do you order the correct replacement parts?

Before ordering replacement parts, make sure you have the fan model and serial number.

Where can I find instructions to wire a motor on my fan?

The nameplate of the motor includes a wiring diagram. Wiring diagrams can also be found beneath the motor image in our Buy Parts section. Simply click the wiring diagram icon to view it.

Can I install a thermostat?

Yes, but only if the thermostat has a simple on/off operation. Please note: if the thermostat varies the amount of voltage delivered, it will damage the motor and void the warranty.

Can I install my whole house fan vertically?

Comfort Cooler (CC) series whole-house fans may be mounted vertically, however, the AS and CSS shutters will not function properly in the vertical position. We do not carry a ceiling shutter for vertical installation. Vertical installation instructions.

Quality Products

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FHIR Series: The True Reversible Intake/Exhaust Fan for Industrial Applications

QUALITYProducts.
SINCE 1948.

FHIR Series: The True Reversible Intake/Exhaust Fan for Industrial Applications

Triangle Engineering’s FHIR Series wall fans deliver true reversible performance in a single, rugged unit. Engineered to function equally as supply or exhaust, the FHIR line combines symmetrical cast aluminum airfoil blades with a fully bi-directional venturi to maintain consistent airflow in both directions. Unlike traditional reversible fans that lose efficiency when reversed, the FHIR Series delivers reliable CFM whether drawing in fresh air or exhausting heat and contaminants.

Built in the USA with galvanized steel housings, welded construction, and powder-coated venturi panels, these severe-duty fans are designed for long service life in demanding environments. A totally enclosed motor and included reversing switch (field install) simplify operation, while belt-drive and direct-drive options let you balance performance with maintenance preferences.

Available in 30″, 36″, and 48″ blade sizes with horsepower options up to 3 HP, the FHIR Series provides flexible voltage configurations and ships ready for straightforward wall mounting. Backed by more than 70 years of American manufacturing expertise, Triangle Engineering’s FHIR Series is the go-to choice for facilities that need the versatility of supply and exhaust without compromising on airflow or durability.

True Reversible Performance

  • Bidirectional Venturi: Unlike typical “reversible” fans that lose efficiency when reversed, our venturi is engineered for equal airflow in both directions.
  • Symmetrical Airfoil Blades: Each cast aluminum blade is designed to move air with minimal drag and no loss of performance, ensuring near-identical CFM whether supplying or exhausting.
  • Totally Enclosed Motor (TE): Keeps dust and debris out for longer service life. Our motor design is optimized for smooth, reliable reversibility.

Built to Last

  • Welded Construction: The rugged, industrial-grade housing is made from galvanized steel to resist corrosion, ideal for harsh conditions in factories, warehouses, and agricultural settings.
  • Polyester Powder-Coated Venturi Panel: Added protection against rust and wear, ensuring your fan stays in top shape year after year.
  • Belt-Drive or Direct-Drive: Choose the configuration that fits your application. Belt-drive models come standard with pillow block bearings for smooth operation.

Ready for Quick Installation

  • Galvanized Wall Housing (Standard): Simplifies mounting and saves time—no extra framing required.
  • Reversing Switch Included: Every FHIR fan equipped with a totally enclosed motor ships with a reversing switch (field installed), allowing for seamless airflow direction changes once installed.
  • Maintenance Friendly: All components—motor, belts, bearings—are readily accessible for straightforward service or inspections.

Wide Range of Configurations

  • Blade Sizes: 30″, 36″, and 48″ to accommodate a variety of facility sizes.
  • Horsepower Options: Available in 1, 2, or 3 hp models (contact us for additional motor requirements).
  • Voltage Flexibility: Standard single-phase (115V, 230V) and three-phase (230V, 460V) configurations. Additional options include 277V, 208V, 415V, and 575V to fit specialized applications.

  • Fan Type: True Reversible Industrial Wall Fan (Supply & Exhaust)
  • Drive Options:

    • Belt Drive (with pillow block bearings for smooth operation and easy tension adjustments)
    • Direct Drive (low-maintenance design)

  • Blade Diameters: 30″, 36″, 48″
  • Horsepower Range: 1 hp, 2 hp, 3 hp
  • Motor Enclosure: Totally Enclosed (TE) motor for durability in dusty or moist environments
  • Venturi Design: Bi-directional, polyester powder-coated steel construction
  • Impeller: True symmetrical cast aluminum airfoil blades
  • Voltage: Single-phase (115V, 230V), Three-phase (230V, 460V), optional (277V, 208V, 415V, 575V)
  • Switch: A reversing switch (field install) ships with all models equipped with a totally enclosed motor
  • Construction: Galvanized wall housing and polyester powder-coated venturi
  • Mounting: Wall mount with included galvanized housing
  • Performance Data: Airflow capacities range from approximately 5,500 CFM up to 28,300 CFM. For detailed performance at various static pressures, see the Triangle Engineering product catalog.

At Triangle Engineering, we understand that no two ventilation needs are exactly alike. That’s why we offer a range of customization options for the FHIR Series to ensure the perfect fit for your application:

  • Custom Voltage & Motor Options: Need a different voltage or motor configuration? We can accommodate a variety of power requirements beyond our standard offerings.
  • Alternative Coatings & Finishes: For environments with high humidity, corrosive chemicals, or extreme temperatures, we offer specialized coatings to enhance durability.
  • Mounting & Installation Modifications: Whether you need a unique mounting solution or additional accessories for installation, we can provide modifications tailored to your facility.
  • Specialized Control Integration: Integrate with variable frequency drives (VFDs) or building management systems (BMS) for automated and energy-efficient operation.
  • Custom Airflow & Performance Adjustments: If your application requires a specific airflow range or static pressure handling, our engineering team can design a solution that meets your needs.

Contact us today to discuss how we can customize the FHIR Series to optimize your ventilation system

  1. No Performance Compromise
    The combination of a true bidirectional venturi and symmetrical airfoil blades ensures consistent airflow capacity in both forward and reverse modes—unlike traditional reversible fans that can experience significant drops in CFM.
  2. Industrial-Grade Durability
    From welded construction and galvanized finishes to totally enclosed motors, the FHIR Series stands up to demanding environments—day in, day out.
  3. Time & Cost Savings
    One fan for both intake and exhaust cuts down on equipment expenditures, reduces installation complexity, and simplifies maintenance schedules.
  4. Plug-and-Play Reversibility
    A reversing switch (included, field install) and a robust motor design let you toggle airflow direction quickly, adapting your ventilation strategy to any condition.
  5. Trusted Since 1948
    Backed by Triangle Engineering’s decades-long heritage of quality and innovation, every FHIR Series fan is factory-tested and supported by a knowledgeable customer service team.

Effective ventilation isn’t just about removing stale or hot air—it’s about flexibility. With the FHIR Series, you can seamlessly switch from exhaust to intake without the performance drop-offs typical of “reversible” fans that simply reverse motor rotation. This true reversible design helps facilities:

  • Control Internal Temperatures by bringing in cooler outdoor air during off-peak hours.
  • Promote Healthier Air Quality by flushing out contaminants and quickly replenishing fresh air.
  • Reduce Equipment Costs by eliminating the need for separate intake and exhaust fans.

  • Shutters or Louvers: Prevent unwanted backdrafts and protect the fan opening from weather.
  • Protective Guards: For added safety around moving parts.
  • Rainhoods: Shield the external opening from rain, snow, or wind-driven debris.
  • Speed Controllers / VFDs: Automate speed adjustments for energy savings and integration with building management systems.

For over 75 years, Triangle Engineering has been a trusted name in industrial ventilation. Our commitment to quality, durability, and performance sets us apart. Here’s why customers continue to choose us:

  • Proven Reliability: Our fans are built to last in the most demanding environments, from manufacturing plants to agricultural facilities.
  • Precision Engineering: We design our products to deliver maximum efficiency and airflow, ensuring optimal ventilation performance.
  • Customer-Focused Solutions: We work closely with our clients to provide customized ventilation solutions tailored to their specific needs.
  • Made in the USA: Proudly engineered and assembled in the United States with a blend of domestic and foreign components.
  • Exceptional Support: Our knowledgeable team is here to assist with product selection, customization, and technical support.
    Triangle Engineering: Solutions you can trust since 1948.

Details

  • Reversible totally enclosed motor
  • Welded construction
  • Comes standard with galvanized wall housing
  • Comes standard with reversing switch
  • Polyester powder coated venturi panel

See full specifications for sizing and performance data

View Full Specs
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