System Description

Heating section
The heating system is controlled on the air side, i.e. coolant continuously flows through the heat exchanger. Regulation of heating is performed via the position of the temperature mixing valve.
Depending on the position of the temperature mixing valve, a certain portion of warmed air is mixed with the fresh air from the outside.

Air-conditioning section
The preselected temperature is controlled automatically. The interior temperature and air flow can be adjusted manually via two pushbuttons. The changes are shown in the display. Information from the outside temperature sensors, interior temperature sensor and the sun sensor are processed to regulate the interior temperature. The system can respond to rapid changes in the outside temperature and also takes into account that the intensity of sunlight has a major influence on the subjective temperature perception by passengers.

The fully automatic control system influences the temperature distribution between the upper and lower areas of the passenger compartment to suit the desires of the passengers in most cases. It is nevertheless possible to control this distribution manually by means of the corresponding push buttons. As is familiar from other Porsche vehicles, the air conditioning of the Boxster is also equipped with a "Defrost" switch. This switch ensures maximum window-defrosting efficiency by suitable control of the heating and blower power and the air distribution. In the interest of simpler use, only one button has to be operated here to direct the full heating power to the windows in order to ensure rapid defrosting when the vehicle is operated under winter conditions.

A quantity-controlled compressor produces the cooling power of the air conditioning.
With this demand dependent quantity control, the compressor makes a contribution towards energy savings. When the compressor is switched on, only approx. 6 % of the refrigerant quantity is pumped. The start-up jerk that occurs with uncontrolled compressors can be largely avoided in this way.