THE ACU-802 SERIES AIR CONDITIONING/HEATING UNITS provide maximum passenger comfort in all types of aircraft. Available in a wide variety of configurations, these units meet the requirements of all aircraft operators regardless of fleet size or local ambient conditions. Using R-134a refrigerant, the ACU-802 Series are environmentally “Safe” causing no damage to the atmospheric ozone. The units employ an air-to-air type refrigeration system, and for operators requiring heat, can be supplied with an optional reverse-cycle “heat pump” system. Provisions are made to utilize engine coolant heat to augment the reverse-cycle heat mode. The “change-over” from one mode to another is so simple that it can be performed by the operator on the ramp while the unit is in service. There are no dangers of combustion or its by-products near the aircraft.