Cabin Heating & Cooling Systems


  • Cabin heat is the system used to condition the air for the pilot and passenger's comfort during colder months and higher altitudes
  • There are two main systems:
Heat Exchanger
Figure 1: Heat Exchanger

Heat Exchanger:

  • Inlet air is bypassed through an exhaust shroud
  • Air is ducted from exhaust shroud, now heated, into ventilation ducts inside of the cabin [Figure 1]

Combustion Heater:

  • Uses fuel from the aircraft fuel system to support a flame in a designated heater unit
  • Hartzell Combustion Heater Assembly
    Figure 2: Hartzell Combustion Heater Assembly
  • Air enters the combustion chamber by use of a fan or ram air where it is then burned inside a shroud [Figure 2]
  • The resulting warm air from the shroud is routed into the cabin while the exhaust gas is vented overboard
  • Heat is regulated with a thermostat

Cabin Heat Malfunctions:

  • Exhaust pipes may burst allowing carbon monoxide to enter the cabin
  • Heaters may have the same problem with the internal combustor


  • Carbon Monoxide Poisoning in a silent killer who's risk can be mitigated through a few simple steps
  • Especially in winter months, refresh your knowledge on Carbon Monoxide and conduct an extra thorough preflight
    • Remember, the heater system may have gone unused for months
  • You can find more information about your aircraft in Chapter 7 of the Pilot Operating Handbook