Electronic Control Unit (ECU)


The ECU is located in the center console, beneath the instrument panel. It regulates the evaporator blower speeds and heater. Additionally it provides outputs for actuator positions as required.


Air Distribution


Air Conditioning

When air conditioned air is required, the evaporator blower is actuated and air is distributed through the duct in cabin ceiling and in the rear panel behind the baggage area.


Heat

When cockpit heat is required, the compressor and evaporator blower are turned off and the existing heater in the forward cabin is turned on. Heated air is distributed approximately 90% to the floor ducts in the cockpit with the remaining air being diverted to the defog ducts.


DeFog

When the Defog " " mode is selected the existing defog valve is activated at and air is distributed to the windscreen. Temperature selection on the digital Switch Panel regulates the temperature of the defog air.


Quality Control

  • Each component in this system is tested by the manufacture and again by A/C systems, LLC before installation. All components and hoses are tested at 2X the pressure required during operation.
  • The wiring harness is manufactured by a harness machine and scanned by a computer scanner to assure correct location and bonding of all pins and connections. Only two field connections are required at installation, this design reduces possible errors during installation.
  • All actuators, switches and sensors are tested for operation and condition.
  • All structural parts are powder coated per FTA-STD-1 for maximum protection.

Outside Air Temperature Sensor


 The outside air temperature sensor is located in the engine compartment and is exposed to the airflow into the compartment. This temperature sensor continuously measures the temperature of the air passing by the outside of the aircraft. The ECU uses the 

INTRODUCTION


The Beechcraft Bonanza 36 series Vapor Cycle System (VCS) air-conditioning system is not a primary flight system. However, the system does perform the very important function of providing pilot and passengers comfort while the aircraft is on the ground, taxiing or in flight. Aircraft air-conditioning systems must not only provide effective passenger cooling, but must also maintain a high reliability level to minimize aircraft downtime.


SYSTEM DESCRIPTION


The Beechcraft Bonanza 36 series (Vapor Cycle System) air conditioning system consists of an engine driven compressor, a condenser/fan module, a receiver-dryer with Trinary pressure switch and an evaporator with an expansion valve and evaporator coil temperature sensor. Refrigerant barrier hoses connect the components. A combination of Steel and Aluminum fittings are used.


The system is controlled by an Electronic Control Unit (ECU) that will control the air conditioning and heat automatically or manually. Also incorporated into the ECU is a safety feature that will turn off the A/C in the event of an alternator failure or electrical over load. The system completes a diagnostic test each time it is turned on. There is also an advance diagnostic feature that is designed primarily for technicians.


ENVIRONMENTAL CONTROL SYSTEM-AIR CONDITIONING DIAGRAM



Cabin Temperature Sensor


Cabin temperature is determined by comparing the inside temperature of the aircraft with the desired cabin temperature setting. The temperature is regulated by cycling

Evaporator Assembly


The evaporator removes heat and moisture from air entering the aircraft cabin. The unit is located in the empennage just aft of the aft cabin bulkhead. This assembly utilizes a plate and fin type evaporator coil.

Condenser/Fan Assembly Type

Giving up its heat causes the vapor to change to a liquid. Under average load, two-thirds of the condenser contains refrigerant vapor and the other one-third contains liquid refrigerant. The liquid refrigerant in the condenser has lost much of its heat, but sill remains at a relatively high temperature and pressure.

VCS Compressor


The Beechcraft Bonanza 36 Series utilizes a swash or wobble-plate-type axial compressor. The displacement of the compressor is 147cm3. The compressor cycles to regulate cabin temperature and to avoid evaporator coil freeze-up.

The Beechcraft Bonanza 36 series Vapor Cycle System (VCS)​ - description

at 190 psi (13 bar). The other portion of the switch protects the system from damage due to low refrigerant or excessive pressures by turning off the compressor. Power to the compressor is interrupted once the refrigerant pressure drops below 29 psi (2 bar) or exceeds 397 psi (27 bar) at the Trinary switch. The Trinary switch automatically resets once pressures are restored to a safe level. The receiver/dryer assembly is located in the empennage of the aircraft, adjacent to the condenser/fan assembly.

Trinary Switch


The Receiver/Dryer acts as a storage and filter unit for refrigerant and oil. The Trinary switch serves two functions. One portion of the switch cycles the condenser fans once the refrigerant pressure reaches 235 psi (16 bar) and turns off the

EXPANSION VALVE


The expansion valve is located at the inlet to the evaporator. It is a connection point between the high-pressure and low-pressure side of the refrigeration system. The expansion valve determines the flow rate of the refrigerant and provides a pressure drop, reducing pressure on the liquid refrigerant before it enters the evaporator.

The VCS compressor is engaged by a 12V/28VDC magnetic clutch driven by a V-Belt off the back of the engine via the Teledyne Continental Motors (TCM) accessory drive. The magnetic clutch is switched off during air conditioning operation anytime the refrigerant system pressure drops below 29 psi (2 bar) at the Trinary switch or anytime the high-pressure side of the refrigerant system rises above 397 psi (27 bar).Type your paragraph here.

Cockpit Heater Temperature Actuator


Heated air temperature in the cockpit is adjusted via the existing cockpit heater valve. During the heating mode, the Heater Temperature Actuator opens and regulates the existing cockpit

heater valve via the existing cable actuation. This actuator is located behind the instrument panel. Its adjusting range extends from "heating final stop" (all air channeled from the heat exchanger) to cooling "final stop (no air channeled from the heat 

Evaporator Blower


The evaporator blower draws cool, dry air from the evaporator assembly and ducts it into the existing overhead cabin vent system.

The tubing is hydraulically expanded into the fins to ensure good thermal conductivity. Low-pressure liquid refrigerant from the expansion valve enters the evaporator. Because of the reduced pressure, the refrigerant boils into a vapor. The boiling refrigerant absorbs the heat from the incoming air as it changes from a liquid to a vapor.

exchanger)". The Cockpit Heater Temperature Actuator is activated according to the temperature selected on the digital Switch Panel located in the cockpit.

signal from this sensor to calculate the temperature for the Outside Air Temperature (OAT) indication on the digital Switch Panel display.

the compressor and regulating the evaporator blower speed during cooling requirements and by regulating the heater temperature door during heating requirements. The temperature sensor assembly contains a calibrated thermistor and fan used to draw cabin air over the thermistor. The sensor assembly is located on the inside of the center console. If the sensor fails manual temperature control will be required by pilot input into the Switch Panel.

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Defog Valve Actuator


During heater operation, warm air is normally distributed to the floor area of the aircraft. When the Defog mode is selected the Defog Valve Actuator opens the existing defog valve via the existing cable actuation and distributes air to the defog outlets. The actuator operates in either a "full on" or "full off" position. A minimum of approximate 10% of the air distributed by the heater is distributed to the defog ducts anytime the heater is operating. 

The condenser receives high-temperature, high-pressure vapor from the compressor. The assembly is located in the empennage and draws air from the empennage compartment and vents the exhaust air overboard through a side duct in the aircraft. The refrigerant vapor enters at the upper fitting of the condenser. As the vapor flows through the condenser,it releases heat to the cooler ambient air flowing over the condenser.

Rear Heater Temperature Actuator-Manual Operation


Heated air temperature in the cabin is adjusted via the existing rear cabin heater valve. During the heating mode, the Heater Temperature Actuator opens and regulates the existing rear cabin heater valve via the existing cable actuation. This actuator is located behind the instrument panel. Its adjusting range extends from "heating final stop" (all air channeled from the heat exchanger) to cooling "final stop (no air channeled from the heat exchanger)". The Rear Heat Temperature Actuator is activated according to the position selected on the Rear Heat Rocker Switch located on the ceiling console, between the first and second rows of seats. This location allows both front and rear occupants (in the second row) to adjust the rear heat independently of the cockpit heat. The bar indicator, indicates the % of rear heat that is selected.