2007 Lexus RX 400h Navigation Manual - Page 270

RX400h_Navi_U (L/O 0608) 270 AIR CONDITIONING To switch air intake mode manually - The air intake control button is used to switch between the OUTSIDE AIR mode and the RECIRCULATED AIR mode. With the button set to the OUTSIDE AIR mode, the indicator light will turn off and the system will take fresh outside air into the vehicle. To quickly circulate cooled air, push the air intake control button for RECIRCULATED AIR. The indicator light will come on. For normal use, it is best to keep the air intake control button set to the OUTSIDE AIR mode. If recirculated air is used during heating, the windows fog up more easily. To prevent the windshield fogging, the air intake mode may change automatically to the OUTSIDE AIR mode depending on the air conditioning system. For example, when the ambient temperature is low, the air intake mode may change automatically to the OUTSIDE AIR mode. This is not a malfunction. When the air conditioning is on, if the engine coolant temperature or electric compressor inverter temperature becomes extremely high, the RECIRCULATED AIR mode is automatically selected. In this case, it is not possible to return to the OUTSIDE AIR mode. This is not a malfunction. When the engine coolant temperature or electric compressor inverter temperature is lowered, the previous mode resumes.