Indirect fired gas make-up air units

IFG indirect fired gas make-up air units are available in three housing sizes incorporating eight blower sizes (9" through 20" single blowers and 10" twin blower units) with air flow capacities from 800 to 15,000 CFM, heating capacities to 1,200,000 BTU input/960,000 BTU output, and total static pressures up to 4" w.g. The furnaces used in the Model IFG are AGA and CGA certified and FM compliant.

These units are offered in a choice of three housing sizes, two discharge orientations and five curb/mounting arrangements.

Standard Construction


    • Heavy-gauge weatherproof galvanized steel housing
    • Downturn plenum
    • 1" thick 3# density fiberglass insulation
    • Large gasketed access panels with draw tight tooled fasteners
    • Heavy-gauge base frame with lifting lugs
    • Intake hood with bird screen
    • V-bank filter rack
    • 1" permanent filters


    • Forward curved double width, double inlet blowers
    • Statically and dynamically balanced blower wheels
    • Precision machined shafts and sealed ball bearings
    • Adjustable motor mount and drives with belt selected for 165% of motor horsepower
    • NEMA frame ODP motor
    • Three phase 1 HP and above motors are EPACT high efficiency rated
    • Blower and motor mounted on vibration isolators


    • Gas controls with spark pilot
    • High temperature limit switch
    • 409 stainless steel heat exchanger
    • Aluminized steel burners
    • Natural gas
    • Two stage discharge temperature control


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    IFG Indirect Fired Gas Make-Up Air Unit (Outdoor)
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    IFG Indirect Fired Gas Make-Up Air Unit (Indoor)
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    IFG with Mixing Box (Low CFM)
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    IFG with Mixing Box (High CFM)
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    IFG Roof Curb Arrangements
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    KEES, Inc.
    KEES, Inc.
    KEES, Inc.

    Other Information

    Options & Accessories


      • Flat filter section in intake hood
      • Delete intake hood
      • Foil faced insulation
      • Double wall insulation
      • Painted housing
      • Stainless steel housing
      • End discharge
      • Top discharge
      • Duct adaptor
      • Four way discharge head
      • Floor rubber in shear isolators
      • Floor spring isolators
      • Hanger spring isolators
      • DX cooling coil module
      • Chilled water coil module
      • Evaporative cooling module


      • 2" permanent filters
      • 1" disposable filters
      • 2" disposable filters
      • 1" 30% filters
      • 2" 30% filters


      • TEFC
      • Two speed, two winding
      • Two speed, one winding (three phase)
      • Premium efficiency (three phase)


      • Low leakage opposed blade damper
      • Two position spring return actuator
      • Intake or discharge mounting
      • End switch
      • Return air damper with numerous actuator options


      • Fan disconnect switch (non-fusible or fusible)
      • Single point pre-wired motor control center with main fusible disconnect, starter(s) and fused transformer (located within the unit or remotely)
      • Exhaust fan starter
      • Remote motor control cabinet
      • Remote control panel
      • Remote control panel with indicator lights
      • Low temperature limit switch (freeze stat)
      • Mild weather thermostat (inlet air sensor)
      • Clogged filter switch with indicator light
      • Convenience outlet (service receptacle)
      • Time delay relay
      • Time clock (seven day)
      • Smoke detector
      • Variable air volume with frequency drive
      • Maxitrol A200 DDC compatible control
      • High/low gas pressure switch
      • High gas pressure regulator
      • Mechanical modulation discharge temperature control
      • Electronic modulation discharge temperature control
      • Room override thermostat (requires electronic modulation)


      • Chilled water coil, ARI 400 tested, copper tubes with aluminum fins
      • DX coil, ARI 400 tested, copper tubes with aluminum fins
      • Evaporative cooling with microprocessor controls


      • Propane in lieu of natural gas
      • Power venting
      • 321 SS heat exchanger in lieu of 409 SS
      • 409 burners in lieu of aluminized steel

      Contact the factory for any other options or accessories not listed.