2007 Toyota Prius Owners Manual - Page 313

If manual switching of air intake is desired- The air intake control switch is used to switch the air intake between the OUTSIDE AIR mode and RECIRCULATED AIR mode. With the switch in the OUTSIDE AIR mode, the system will take fresh outside air into the vehicle. 2−way air intake control To improve fuel economy, OUTSIDE AIR mode control changes when the air intake selector is set in OUTSIDE AIR on the following conditions: D When the maximum heating is needed with the air flow Windshield", fresh per compartment, lated in the lower in "Floor" or "Floor/ air flows in the upwhile air is recircucompartment. 27p160a If quick circulation of cooled air is desired, touch the air intake control switch for RECIRCULATED AIR. The indicator will come on in the instrument cluster while the RECIRCULATED AIR mode is selected. D When cooling is needed, both fresh and recirculate modes turns on. Type 1 and Type 2 If recirculated air is used during heating, the windows will fog up more easily. If the hybrid system is turned off in the OUTSIDE AIR mode, the automatic control of the air intake is activated when the hybrid system is turned on again. 27p115a Type 3 296