Best way to defog front window

Usually you can just turn on the AC button, and use Mode to select the picture that shows some to the windshield. I've never encountered a need for the Defrost button in summer. If the fogging is not bad, you can choose the BiLevel picture in Mode (Feet & Dash Vents) initially or after the car has been driven a while, which usually is fine on ours.

 

The defrost button turns on the compressor, so if it's really bad in the beginning, just use that first, then switch to auto.

 

If you leave the system set on "Auto" it will continuously dehumidify the air -- you should not have a problem. In the winter time you may need to use the defrost button. I never have a problem

You are taking about the condensation inside ...correct.

 

You mean it will switch the Air Conditioning (aka compressor/freon/cooling) on as needed? I thought that at the outset, but now I'd say if the AC button is not depressed, the AC is off, regardless if the system is in "Auto" mode.

AFAIK, the only thing that will force AC on is pushing the front defog button.

 

I always forget that Toyota calls that the "AC" button and not the "econ" button - mine is never in the "off" position .......... If you hit the "auto" button in every car I have ever owned the compressor will run ...... how can it be automatic climate control without the compressor running?? All our Lexus vehicles work that way - so I'm not sure why they do the "AC" button it on the Prius. I understand the need for the button on manual systems.

 

I'm not 100% sure. But I think if you for example set auto, and a fairly cool temperature, but don't depress the AC button (the light on the button is off), on a warm day it will try valiantly to bring the temperature down via raising the fan speed, but won't run the Air Conditioning compressor.

Again, I'm not sure on this. FWIW, I like this approach, ie: I like being in control or whether AC is running or not. And I know, it's more typical with "auto" systems that the AC invariably does run, as needed.

Our last car, a second gen Honda Civic Hybrid was like that: hit Auto and likely AC would come on. But you had the option to hit the AC button to disable it. It would then continue as full Auto except for disabled AC.

The Owners Manual's confusing in that they adopt the term "air conditioning" to mean anything relating to moving air through the system, not just active cooling.

 

Nothing new, my Cadillacs were all like that. You could the compressor off in any setting but defrost.

 

My point is that on a car with Automatic Climate Control (ACC) the auto button should be just that ....... automatic --- and on most cars that is what it is ...... get into the car and by hitting the "auto" button the system resets back to fully automatic operation removing the previous driver's settings. The compressor must be working for the system to function correctly! When you hit the "AC" button to turn off the compressor the indicator light on the "auto" button should go out ............as the system is no longer in automatic mode

Many cars ........but not all of them have a button to keep the compressor off -- using various names ..............."econ" often is used and that button will light up to tell you that the system is in that mode. The "AC" button is a hold over from the manual systems.

 

To each his own. I know what "A/C" means, and what the car is doing when the light is lit or not. I'd have no idea what "Econ" would mean, since my main car has never had such a button. And since I avoid using A/C as much as possible, I'm glad I can hit Auto and not turn it on.

(Similarly, it took me a long time before I figured out that the "Max A/C" setting on a previous car was just the "Econ A/C" but in recirculate instead of fresh mode.)

 

What jim256 said. I have the same issue in NC with the high humidity. I will change the mode to windshield for a while to defog the windshield until it starts to condense on the inside. Then I will switch it back to auto for a while until it starts to fog again.

I usually only have to do this on rainy days or really high humidity.

 

Same in Richmond. Always on AUTO. Only once did I feel the need to hit the defrost button. After two minutes I went back to AUTO.

Also as someone said, if you turn the A/C button off it is now out of AUTO and that light goes out too.

 

Use your AC to keep the humidity low inside. Raise the temp setting a bit & turn the side vents away from the windows to keep the side windows from fogging up on the outside. Use Stoners Invisible Glass on the windows - especially on the inside if you are a smoker.

 

People are confusing what the Prius has .........Automatic climate control - with manual controls usually found in an econobox. Max A/C is just that -- it closes the outside vent and lowers the evaporator set point ... it has nothing to do with "Econ". Basically what the system does when you first startup on a hot day. "Econ" is "Auto" without the compressor -- and is best used while heat is needed in dry climates.

But if you keep the system in full "Auto" with the "AC" button light "on" the ACC will cycle the evaporator below the dew point to keep the humidity down -- I will say that the ACC system in the Prius requires more input than what is typical - I'm always moving the temp up or down a degree or two -- most systems never need to be touched.

 

I don't believe the Prius system has a true Auto system. They usually change the modes on their own, without input from the driver.