Air conditioning (Performance guide-lines): Adjustments

PERFORMANCE GUIDE-LINES

Carry out this test with bonnet, doors or windows open; air conditioning switched on, temperature control set to cold, face vent mode and blower at maximum speed. Set the air supply control to supply fresh air.

1. Close low pressure valve on Refrigerant Station.
2. Close high pressure valve on Refrigerant Station.
3. Connect Refrigerant Station to the high and low pressure servicing connections.
4. With a thermometer measure the air intake temperature, close to the outside air inlet at the plenum.
5. With a thermometer measure the air outlet temperature, at the centre vent outlet.
6. Run the engine at idle speed for 10 minutes or until normal operating temperature is reached.
7. Read both pressure gauges and thermometers. Check readings against the guide-lines shown in the table below.

The temperatures and pressures may be slightly increased for high humidity conditions. The refrigerant pressure will dictate whether the fans operate in series or parallel, which will itself cause the temperatures and pressures to fluctuate. Fans could operate as follows:

• Condenser and cooling fan both running at half speed (series).
• Condenser and cooling fan both running at full speed (parallel).
• Fans switching from series to parallel.