Dual Climate Control

[forevered]

HAVING JUST BOUGHT A USED SR IM CONFUSED WHEN TRYING TO WORK A FEW THINGS OUT WHEN USING THE DUAL CLIMATE CONTROL .

A LITTLE ADVICE PLEASE !

1. WHAT DOES TURNING THE AUTOMATIC SWITCH DO AS OPPOSED TO JUST TURNING THE AC BUTTON ON ?

2. CAN I JUST TURN ON WARM OR COOL AIR WITHOUT USING THE AC ?

[Tomppis]

1. If you choose automatic mode, the car (or computer) makes temperature stay at example 19 C . If you put only AC on, car pushes fresh and cleaned air through and you can choose temperature, where it blows and you "fast".

2. Of course you can, read the manual, there is explanation for what's the difference between AC on or off. AC off takes air straight from outside and pushes it out to inside of car, if you put AC on, it cleans and freshess, (if you could say it that way) and blows it in.

Sorry my bad english I hope you understand at least something.

[forevered]

1. If you choose automatic mode, the car (or computer) makes temperature stay at example 19 C . If you put only AC on, car pushes fresh and cleaned air through and you can choose temperature, where it blows and you "fast".

2. Of course you can, read the manual, there is explanation for what's the difference between AC on or off. AC off takes air straight from outside and pushes it out to inside of car, if you put AC on, it cleans and freshess, (if you could say it that way) and blows it in.

Sorry my bad english I hope you understand at least something.

[forevered]

1. If you choose automatic mode, the car (or computer) makes temperature stay at example 19 C . If you put only AC on, car pushes fresh and cleaned air through and you can choose temperature, where it blows and you "fast".

2. Of course you can, read the manual, there is explanation for what's the difference between AC on or off. AC off takes air straight from outside and pushes it out to inside of car, if you put AC on, it cleans and freshess, (if you could say it that way) and blows it in.

Sorry my bad english I hope you understand at least something.

[forevered]

thanks for that help

[Mooly]

When AC is lit the compressor and "refridgeration" is active and the incoming air is dehumidified and cooled by passing through the cold "evaporator".

Depending on the outside temperature, and the temperature you want that air may then be heated again, but it's now moisture free and as well as stoping you steaming up in damp weather feels much fresher due to the low humidity.

If you turn the AC off the path the air takes is exactly the same... but of course cannot be made colder and does not get dehumidified.

Auto selects the best combination of air flow (lower vents, floor vents etc) for the conditions and temperature you have set. For example if the sun comes out the airflow is directed automatically to the face vents, sun goes in and it combines floor and face vents, goes colder still and it's mainly floor. This is what the sensor on the dash at the base of the screen does.

If you manually alter the fan speed the auto light goes out, but air flow is still altered automatically as above... it's just the fan speed that's fixed at where you set it.

If you change the air flow settings (which vents used) then that function will never alter again until you press auto to reset it.

[hertsnminds]

Auto selects the best combination of air flow (lower vents, floor vents etc) for the conditions and temperature you have set.

This is just as Mooly said. However, you can work out what rules the system uses so you have some idea of what will happen. For example on cold days (outside temp less than 3 deg C) the system will direct warm air to the footwells. When the outside temperature is between 3 and 5 degrees C the system assumes condensation and directs air to windscreen and feet. If the outside temperature is between 10 and 20 degrees C the air flow is usually to the face vents however how fast the fans blow and how often the AC compressor is turned on will be determined by the temperature you have set using the controls.

At any time you can override the auto function and set any of the system functions to suit yourself.

[ikac2000]

I have noticed that, when AUTO and AC are set, outlet air is not so cold compared to car with manual AC (Fiat Punto) set to lowest temperature.

Even if I set LO temperature, air is not as cold as in FIAT PUNTO.

It seems to me that outlet air temperature is controlled, and not freezingly cold as in other cars.

Is it normal, with some purpose (thermal comfor maybe), or may be fault of AC system?

Many thanks...

[Mooly]

I know what you mean... I noticed on both my previous TSport and new Auris that the air is cold but hasn't that really sharp icy feel to it. My old Audi A4 was... before it packed up with a leaky evaporator. Strangely I think you will find the hotter the outside air the colder the air from the vents feels... don't know why but it seems the case. The evaporator matrix (the bit inside the car that gets cold) is designed usually to run a few degrees above freezing so that there is zero possibility of ice formation which would block it. If you lift the bonnet with the AC on the metal piperwork and the small cannister which looks like a "bulge" on the pipework should feel very cold and be wet through with condensation. It's near the alternator... just be careful if the engine is running. The coldest vent I find is the metal one on top of the dash, which does feel very cold.

[ikac2000]

Under the hood, I have found piping, and one is cold, but not condensing. Also, when climate is set to LO it is colder than outside, but not so much.

Air from the vents is colder than outside air, there is condensed water near front right wheel (so evaporator works), but only after 10 min's of driving car is a little bit colder, so I think there is not enough cooling capacity. Maybe I'll schedule visit to Toyota service these days, as car is under warranty.

This is not the case with my Fiat Punto and manual AC, after minute or two, air is sharp cold.

It is very annoying for me that such thing is happening on a 1.5 year old car...

[Mooly]

Do you leave the AC on all year round ? to help stop loss of refrigerant due to lack of use.

It would be interesting to see what Toyota say. I read somewhere a while back, that often new cars are "low" on refrigerant... maybe as an attempt to save money... when I mentioned it on here in a thread it was dismissed as not so. Our Corolla was topped up with gas at 3 years old, dealer said it was not cold enough during a service... and it's now 7 years old and still good cooling. My old TSport I owned from new for 8 years had an AC regass at 4 years old and the cooling seemed much improved... and it was still as good at 8 years old.

That "bulge" or cannister in the pipework should be wet through with condensation with the weather at the moment (high humidity).

[ikac2000]

Do you leave the AC on all year round ? to help stop loss of refrigerant due to lack of use.

In winter, I do not use AC, also in spring, apart from dehumidifying windscreen.

I have scheduled visit to Toyota service.

They mentioned me three possibilities:

1. Low refrigerant if decreased cooling performance (they say that 10-15% of refrigerant can be lost per year, and that is recommended to check / refill every 2 years)

2. Piping leak if car was damaged (not the case)

3. AC Compressor

I will see what will be the case...hope for the best:-)

[ikac2000]

.

[Mooly]

Almost certainly low on gas I'll bet.

There is an oil in the system that circulates with the gas and this helps keep the flexible O ring seals and the front seal on the compressor lubricated and stops them drying out... the main cause of leakage and low gas over time. That's why it's important to use all year round for at least 10 minutes a week.

I leave mine on all the time and have never had any problems.

Let us know the outcome :)

[ikac2000]

After visiting Toyota service, they refilled gas and said that averything else seems to be OK. They said that usually after 3 years you can feel little less AC performance, but in my case car is 1.5 years old, and they suspect that it was not filled properly in the factory.

Now it is better cooling, I must admit, but still not sharp cold like on my Punto on idle (I guess Toyota has milder cooling).