Distribution

HVAC HOUSING
The HVAC housing is mounted under the instrument panel to the dash panel. It houses the heater core, evaporator coil, blower motor and a series of doors. The doors are used to direct air from the blower motor to venous duct and through the heater core/evaporator coil.

The system draws outside air through the cowl opening at the base of the windshield. It then flows into the plenum chamber above the Heater A/C unit housing and passes through the evaporator. At this point airflow can be directed either through or around the heater core. This is done by adjusting the blend-air door with the TEMP control on the control head. After the air passes the blend air door, the air flow is then directed from the PANEL, BI-LEVEL (panel and floor), and FLOOR-DEFROST outlets. Air flow velocity can be adjusted with the blower speed selector switch on the control head.

Ambient air intake can be shut off by closing the recirculating air door. This will recirculate the air that is already inside the vehicle. Rotating the MODE control knob to the Defrost/Floor or Defrost setting on the control head will engage the compressor. This will send refrigerant through the evaporator, and remove heat and humidity from the air before it goes through the heater core.