A/C comes on with AUTO... always?

The a/c is coming on because you are selecting Auto and the car feels that because of the temperature and humidity that a/c is required. I personally just let the car work it out as in winter it will still switch on the a/c if needed to demist the windows, but it does lower the a/c or even switch it off (even though the a/c light is still on) if it isn't required.

Or you can manually switch the a/c off and still leave the system in Auto and it'll blow outside air in to cool the car.

Just wait til winter and see what happens. Leaving it in Auto with the a/c lit seems to work fine.

 

it all depends on the outside temp, and the temp you have the climate system set at.

 

Does the Prius have a humidity sensor?

 

Toyota says it does in their brochures.

 

How do you know the A/C has come on?

On the genII Prius the indicator only means that the system can use the cooling if required, it does not mean that it actually is using it.

kevin

 

i don't know about the v, but the pip now has a button w/light for a/c on/off.

 

AC can have uses in the winter. If there is a significant delta in air humidity, even with heat, you still want to adjust the humidity of the air to prevent fogging. AC doesn't just mean cold.

 

The A/C compressor usually won't come on if the outside temp is 40 degrees or less.

 

I just turned AUTO OFF!
When I want heat, I turn the thermostat up, if I want AC I turn AC ON, without hitting AUTO.
Just adjust the thermostat.
Usually a open window works for me!

 

Wonder what it is set on?

 

"AC" stands for "Air Conditioning," not "cooling," although in the US we usually make them synonymous. Conditioning can mean heating, humidifying, and dehumidifying as well as cooling. Put it on Auto, set it for a comfortable temperature, and ignore it. It knows what to do.

 

Personally I don't like Auto mode because it tends to come on with a high fan setting which is noisy and annoying.

 

if you set the temp one degree below outside temp. a/c will come on only one fan bar and very low energy usage. as you turn down the temp, air gets colder and fan goes higher.

 

True, and I've done that as well, but having to fiddle with the temp control to control the fan defeats the purpose of the Auto mode. I prefer to set an interior temp like 74 or 75 or so and set the fan to one or two bars and just leave it there without using Auto. I also don't like the default recirculate mode.

 

The fan only runs really high if there's a big temperature difference. If you set the a/c manually to avoid this situation, then surely you'll spend 10 minutes or more suffering extreme heat or cold?

In 'Auto' setting the fan only blows fast for a min or two until the internal temperature corrects itself and then it slows down accordingly. Well unless you have the a/c switched off and the car is trying to cool the internal temperature with outside air only?

I guess you just can't please all the people all the time.

 

one thing i have found using the pip is that using auto is much more efficient than manual which runs the a/c on high all the time. i do agree about recirc and i also don't like that it's face only and no floor.

 

Only if there's a large temperature difference between the inside of your car and the temperature setting. And then the fan will only run on high until the temperature is corrected, which is at most a few minutes.

Another thing to consider is that Auto is more efficient than manual because the car adjusts it accordingly.

It's easy enough to change both the temp and recirc via the steering wheel without taking your eyes off the road.

 

I'm not sure that the temperature setting does anything at all when Auto is off. I could be wrong about that. But I thought that if you turned off Auto, cooling would work like a standard AC: i.e. you turn it on until you're cold enough, and then you turn it down, all manually.

 

If you run AC in the non-Auto mode, the AC will run until the internal temperature reaches the temperature you set. Auto does the same thing except that it tries to keep the fan speed as low as possible and makes other similar adjustments to save energy and slightly increase MPG. I've found that Auto doesn't allow the AC to cool the car enough or fast enough for my comfort unless you set the temperature to a much colder than normal setting. Auto is to non-Auto what ECO is to PWR. ECO makes the car drive like a slug, but it increases MPG. Auto makes your armpits sweat in the summertime but MPG might increase. I don't mind driving a slug, but I don't like damp armpits.