Recirculate Air On At Startup

[Muadeeb]

Does this happen on everyone else's '02 ES300?

When you start the car, the recirculate air light is on? Is there some way to set this so that it doesn't come on every time?

Thanks,

Michael

[Tyler121]

what temp. do you have it set for? i know if mine is a certain temp. it will automatically go to recirculate.

[wwest]

Does this happen on everyone else's '02 ES300?

When you start the car, the recirculate air light is on? Is there some way to set this so that it doesn't come on every time?

Thanks,

Michael

Yes, generally all cars of asian manufacture will do this, certainly those with climate control systems designed by the idiot Japanese engineers at NipponDenso or US engineers at Denso US.

The base idea is to go to recirculate mode in order to cool the interior down more quickly on a hot, or bright and sunny day. Note that it doesn't have to be HOT outside for the inside of your car to get quite HOT on a bright and sunny day, even a coolish day.

The fly in the ointment is the fact that in most cases the interior atmosphere will have been heated far above the outside ambient temperature as will, in some cases, the interior surfaces themselves.

Example:

It's late in the afternoon and the local atmosphere is cooling, now 75F. But the car has been setting out fully closed up in the hot summer sun all day and the interior atmosphere is at 112F and the seat and other surfaces are hot to the touch. Start up the car, the A/C starts up and moves the system to recirculate. Now the A/C is extraordinarily burdened with cooling the 112F air "trapped" within the cabin plus cooling the extraordinarily heated surfaces.

The way this should work is to use "fresh" mode initially, even at a high blower speed, to move the HOTTER interior atmosphere OUT of the car via the exhauster port provided, until the interior temperature is at least down to that of the outside ambient. Then at that point it becomes, is entirely reasonable, to convert to recirculate mode so the system is not continuously trying the reduce the temperature of the incoming outside HOT airflow.

It is an extremely good idea to use reciculate mode continuously during the times when cooling need(***) is predominant to improve the efficiency of the A/C. Personally I use recirculate continuously and turn the setpoint to max cooling and then use the blower speed to control my comfort level. In that way none of the system airflow goes through the reheat cycle and therefore the A/C compressor runs a lot less often.

Some newer models, maybe yours, have a c-best option that can be set by the dealer wherein this special recirculate mode can be disabled.

***CAUTION...Never, NEVER use the recirculate mode during wintertime, HEATING mode.

Some systems will allow you to keep recirculate mode active as long as the A/C is on and is functional, but the use of the A/C in heating mode, or even in defrost/defog/demist mode, can too easily prove to be HARZARDOUS.