An evaluation of HVAC control panel in passenger cars

The HVAC control panels of a sample of 10 passenger cars were investigated and evaluated in terms of the type and layout of the controls. The evaluation method of the layout for the same task execution is based on Keystroke Level Model (KLM). According to this method, the results in the manual adjustment of the AC parameters with rotary knobs were better than in the panel with the push buttons, for the same function. The automatic AC control significantly reduces the time and number of actions, thus reducing the driver's workload for the HVAC setting. However, the automatic operation could not provide preferable thermal conditions under some conditions or because of individual preferences, making a manual readjustment necessary