A new method of testing and presenting climate control systems airflow rates is presented, using interior vehicle pressure as a parameter. A Polar diagram can be constructed showing the performance of the complete system, that is, ventilation, heater, air conditioner, etc., at a given vehicle speed, normally 60 mph.
Analysis of the Polar curves can aid in improvements to a present system, design of new systems or even help in predicting the performance of future systems not yet built.
The effect of the aerodynamics of the vehicle body shape on internal flow is discussed. The pressures at both the inlet and exit location for the flow are equally important and are easily determined during the wind tunnel test.
With the increasing use of high level instrument panel registers, new methods of establishing design requirements are needed. Subjective rating curves of Hi-Lo distributions are also discussed.