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Make-up Air Systems

WeatherHawk Indirect Fired Outdoor Make-up Air (H-Series)

WeatherHawk indirect fired outdoor make-up air systems are designed and engineered to deliver superior performance in a variety of applications. The unit is constructed of a weatherproof duct furnace with a blower, cooling and/or downturn plenum section designed for use with a building’s heating, heating/ventilation/cooling make-up air system.


  • Superior corrosion resistance and extended equipment life with 18-gauge, polyester-powder paint on an aluminized steel casing
  • Eliminate time consuming field mounting of a box-type disconnect with dead-front disconnect switches
  • Quick and accurate field connections with separate line and low-voltage terminal strips
  • Roof curb mounting without roof penetrations for field wiring and piping possible with bottom gas and electrical connections
  • Ductwork installation before unit arrival at job site with roof curb discharge-air and return-air connection kits
  • Easy wipe down of unit interior with double wall interior liners


  • Blower performance up to 3.0” W.C. is perfect for longer ductwork or accessories with high pressure drops
  • Maximum control of outside ventilation air with fresh and return air dampers with two positions, modulating building pressure control or building management control
  • Fresh air dampers are ultra low leak, Class-II leakage resistance
  • Maximum air volume control with variable frequency drives


  • Circuit analyzers minimize start-up and service time by immediately identifying causes of improper unit operation
  • Troubleshooting easier and more accurate thanks to job-specific wiring diagrams
  • Easy burner/pilot access simplifies inspection and eliminates the need to disconnect gas piping when servicing the burner
  • Full cabinet access provides easy access to unit controls, blower section and filter rack


  • Building-management-system-compatible-controls maximize energy savings according to building occupancy and usage
  • Smoke detectors ensure confidence


  • Heating and cooling from one unit is possible with an installed cooling coil section and factory installed DX or chilled water coil


  • 81% thermal efficiency on all models brings high fuel efficiency to every application
  • 20°-100°F air-temperature rise allows the air volume design flexibility of a contoured and dimpled heat exchanger optimized to withstand thermal expansion and contraction

Standard Features:

  • Available in 17 model sizes (input ranges from 75,000 to 1,200,000 Btu/Hr)
  • Natural or propane gas
  • Airflow ranges from 556 to 14,500 CFM
  • 18-gauge insulated aluminized steel blower cabinet with a baked-on polyester powder paint finish on exterior casing parts
  • Blower performance up to 3.0” W.C. external static pressure

  • Unit can be provided with cooling coil section (either factory installed DX or chilled water cooling coil, or coil can be provided by others)
  • Double wall construction for blower and/or cooling cabinet
  • 2-position, modulating, building pressure sensing, 3-position, building management (0 - 10 Vdc or 4 - 20 mA input) damper actuators
  • Blower and motor vibration isolation
  • Units are third party certified by ETL
  • Available variable frequency drives for maximum air volume control