Automatic Air Conditioning

[Mick F]

Hopefully, someone can solve this little mystery.

Button 14 on the attached picture.  I understand fully what it's for.  Personally, I like it switched off to allow fresh air in rather than on recirculation, though I can see that it's useful on smelly roads.

On Startup .................. maybe 50% of the time, the button is OFF, and the other 50% of the time it's ON ........ so I switch it off.  Once or twice, when it's OFF, it comes back ON again some time later, but once ON, it doesn't ever go OFF during the whole journey unless I switch it off myself.

What's going on?

Mick.

[Heidfirst]

What other settings do you typically have set? If it is like the system in the Avensis it can take into account your other settings e.g. temp. required set & internal & external temps. to most efficiently reach that requested - e.g. it takes less energy to raise the internal temp. if it is not taking in cooler external air. Being a hybrid I suspect that your system's rules are even more biased to energy saving/efficiency than that in the Avensis.

[martswain]

If you are in AUTO with A/C selected, to cool the cabin quickly the system will select recirculation automatically until the desired temperature is reached.

This can also happen if the outside air cannot be cooled enough to reach the selected temperature.

You can check the system is working properly by nudging up the selected temperature (not in DUAL mode) and you'll see the recirc light go off.

[Mick F]

55 minutes ago, martswain said:

If you are in AUTO with A/C selected, to cool the cabin quickly the system will select recirculation automatically until the desired temperature is reached.

This can also happen if the outside air cannot be cooled enough to reach the selected temperature.

You can check the system is working properly by nudging up the selected temperature (not in DUAL mode) and you'll see the recirc light go off.

Mystery solved. I knew someone would come up with the correct info.

Thank you, it makes complete sense now!  I wonder why that info isn't described in the handbook?

Mick.

[martswain]

I had my hybrid for 4 years, before that a Lexus CT200H and two different model of Prius, from what I remember all those that had automatic A/C worked the same way.

The GRMN that I now have works the same with a belt driven compressor rather than the electric one on the hybrid.

[YarisHybrid2016]

The recirc has interesting behavior.

If the system is in AUTO then the whole thing is automatic. If you adjust one parameter, that becomes manual but the rest of the system is still automatic, even though the AUTO light goes out.

If you press OFF, then cycle the recirc button OFF/ON, then switch the system ON again (turn the fan on) then this seems to influence the behavior of the recirc.

If you have any heat selected, then you will find it sometimes opens the recirc, especially if it is attempting to get to the set temperature at night. The reason is that it senses the outside air is cooler, to help the aircon, so it opens up. From what I can tell, the heater function also becomes more effective with recirc OFF.

I've also found that with a temperature set, it seems to react to humidity. If it is more humid inside than outside, it will also switch OFF recirc.

When the system is set to LO, the recirc generally stays ON for maximum cooling.