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Discussion Starter #1
Hi
08, LTD with auto front and rear climate control.

Scenario #1
outside temp 85 degrees, car sitting in sun all day long, inside temp must be about 100 degrees. Air is on recirculate when engine turns on. Why?? Doesn't it make more sense to pull fresh 85 degree air then to recirculate 100 degree air?

Scenario #2
Driving with AC on, outside temp 85 degrees, temp for driver, pass, rear set at 73 degrees. For no reason, pass. setting goes to "max heat" :headbang: Another time, rear temp goes down to 68. :confused:(did not touch any of the controls).


Any explanation or solution to this??
Thanks.
 

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2007 Camry XLE
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Scenerio #1 Opinion is if you shut off the outside air and recycle the inside air it will cool down faster. Guess you would have to run a some controlled tests to validate the manufacturers theory..

Scenerio #2..your Limited uses an artifical intelligence neural network to control the HVAC..."DO NOT QUESTION THE TOYOTA" :ahhhh:

See link for description

Limited HVAC Neural Network
 

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Hi
08, LTD with auto front and rear climate control.

Scenario #1
outside temp 85 degrees, car sitting in sun all day long, inside temp must be about 100 degrees. Air is on recirculate when engine turns on. Why?? Doesn't it make more sense to pull fresh 85 degree air then to recirculate 100 degree air?

Scenario #2
Driving with AC on, outside temp 85 degrees, temp for driver, pass, rear set at 73 degrees. For no reason, pass. setting goes to "max heat" :headbang: Another time, rear temp goes down to 68. :confused:(did not touch any of the controls).


Any explanation or solution to this??
Thanks.

Yeah, your scenario 1 has been my frustration with my 09 since the warmer temps came around. I have the exact same problem. AUTO off, AC off, and I turn the RECIRC off, yet I can turn the car off, and then on again, and the RECIRC automatically comes on again and blows the steaming hot interior cabin air in my face. I spent C$40 K to have to push the recirc every time I get in the car??? :headbang:

This only occurs if the temp setting is colder than interior cabin temp. I can understand the recirc coming on IF I have the AC on, because recirc'd AC air will cool the interior much more quickly. However, I am more a fan of fresh air than AC, so I often have the AC and AUTO off, and therefore find myself driving a minute or two before realizing that the temp is rising and have to push the the recirc button. If Toyota wants the recirc to be automatic, then it should only come on if the AC is on, not if the AC is OFF! OR, it should only work automaticaly in AUTO mode. :headbang:

Anyway, I have my first appt with the dealer Thurs, and besides the rotten egg smell that I am getting every time I accelarate (even if I have windows closed, AC on and recirc on, believe it or not), this recirc isssue is at the top of my list.

We'll see if they have a fix, but I'm not holding my breath.

Cheers.
 

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Now - 2011 Explorer Ltd
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Hi
08, LTD with auto front and rear climate control.

Scenario #1
outside temp 85 degrees, car sitting in sun all day long, inside temp must be about 100 degrees. Air is on recirculate when engine turns on. Why?? Doesn't it make more sense to pull fresh 85 degree air then to recirculate 100 degree air? Any explanation or solution to this?? Thanks.
I was very disappointed to read this. I have an '06 HL Ltd. that does the same thing. This was one area I hoped would have been addressed for the newer models. My '09 Ltd. has just arrived although I won't be picking it up for a few weeks. From what I'm reading, it looks like I can look forward to a few more frustrating years, having to manually turn the recirc button off so I can pull cooler air in from outside!! :headbang:

Peter
 

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Guys......the auto climate control puts the system on recirc because this is the fastest way too cool the inside of your vehicle. You may not like it but I am sorry its the truth and no, Toyota is not the only makers that know this.

My dads 04 Chrysler Pacifica does it, my 07 Tundra did it, my 06 MINI Cooper S does it, etc....

For those of you that have the Auto Climate control...run it in manual mode instead if you don't like recirc.
 

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Guys......the auto climate control puts the system on recirc because this is the fastest way too cool the inside of your vehicle. You may not like it but I am sorry its the truth and no, Toyota is not the only makers that know this.

Absolutely not true, and even your owners manual will tell you so. The owners manual will tell you to lower the rear windows (slightly) to more quickly cool the cabin after the car has been setting closed up on a bright sunny day.

My dads 04 Chrysler Pacifica does it, my 07 Tundra did it, my 06 MINI Cooper S does it, etc....

So, if others do it then it must be right...??

NOT...!!

For those of you that have the Auto Climate control...run it in manual mode instead if you don't like recirc.
Your Toyota dealer can set a c-best option that disallows the recirc mode in this situation.

I always run the A/C in my RX300 at MAX cooling for highest efficiency during the times cooling is required but ALWAYS over-ride the recirc mode until the cabin is cooled to a reasonable level and then switch it to recirc.

I use the blower speed to moderate the level of cooling desired.
 

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2008 Highlander Base
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I don't like a lot of air blowing on me so I usually regulate the temp by adding some heat while the A/C is on. I find my Highlander's A/C system is very, very effective and usually have the heat turned about 25% of the way to hot in order to produce a comfortable temperature. I'd still rather do it that way than have HAL do it for me....:lol:
 

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Guys......the auto climate control puts the system on recirc because this is the fastest way too cool the inside of your vehicle. You may not like it but I am sorry its the truth and no, Toyota is not the only makers that know this.

My dads 04 Chrysler Pacifica does it, my 07 Tundra did it, my 06 MINI Cooper S does it, etc....

For those of you that have the Auto Climate control...run it in manual mode instead if you don't like recirc.
Unfortunately, the problem as originally reported, unwanted recirculate activation, happens regardless of auto/manual setting. I hate the "Auto" mode since I like to be in as much control of the vehicle's operation as possible (same feeling with driving lights/auto headlights), so I use it about once a year. However, I still have to deactivate the recirculate button every time I start up in the summer. All of my start ups are without AC as I do like others here... I turn my AC off prior to reaching my destination to lighten the load on the battery and expel any moisture before engine shut off.

DeWat
 

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Well we know that Chrysler, Toyota and BMW think its the right thing to do when the Auto Climate control is first turned on. I like it the way it is.
 

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I don't like a lot of air blowing on me so I usually regulate the temp by adding some heat while the A/C is on. I find my Highlander's A/C system is very, very effective and usually have the heat turned about 25% of the way to hot in order to produce a comfortable temperature. I'd still rather do it that way than have HAL do it for me....:lol:
The Base model does not have all of the computer controlled logic.

Only the dual zone automatic system uses the artifical intelligence neural network logic to control things

You have more manual control over things in the base model

Also the AC uses a compressor and pulley that is a continously variable capacity type in which the its capacity can be varied in accordance with the cooling load of the air conditioning which reduces the load on the engine and improves fuel economy
 

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If you have AC and AUTO on, yes it makes sense that the recirc would come on to cool the interior more quickly. I do notice that recirc'd air is cooler than cooled air from outside.

HOWEVER, my issue is that even when I have AUTO AND AC OFF (I just want fresh unconditioned air), the recirc button still comes on when I restart the vehicle.

How is it logical that recirc'ing 100 degree interior cabin air will cool the interior more quickly :confused:

Anyway, wwest, thanks for the info on the c-best setting. Will raise it with my dealer on Wed when my HL goes in for its first visit...hopefully it will take care of this annoying situation.

Cheers.
 

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Let us know if the dealer is able to change that setting for you
 

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The Base model does not have all of the computer controlled logic.

You have more manual control over things in the base model
That was one of the main reasons I bought the Base model...I'm not a technophobe, but I don't like "computer controlled" anything and prefer the manual touch.

BTW, man, I don't mean to imply by my answer that I thought you were calling me a technophobe...it's little things like that which can lead to misunderstanding...thank goodness for emoticons....:D :thumbsup:
 

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BTW, man, I don't mean to imply by my answer that I thought you were calling me a technophobe...it's little things like that which can lead to misunderstanding...thank goodness for emoticons....:D :thumbsup:
Wasn't implying anything.

Just clarifying.

The one thing Toyota owners have to deal with is "Toyota knows what is best for you" engineering practice.

They make it difficult for an owner to make custom changes to how things work and it took a while for them to install a switch to allow the owner turn off VSC when situations call for it.

Toyota builds a great product but they seem to feel owners are idiots and need a nanny to protect them.
 

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As to #1, recir is way more efficient than fresh air. Why? Well lets take a little tour.

If the outside air is 85 and your inside air is 105, cooling off that air will be a lot faster than cooling off the outside air and forcing it inside. Recir does just what it says, it take air from the inside and passes it back through the AC/Heat system and blows it back into the cabin. If you are taking "fresh" air in you will 1) have more contaminants from outside (esp. on the road) into the filter and cabin and 2) have a less efficient system due to it trying to blow air into an already full space (i.e. ballon effect).

Internal air pressure stays the same and air temperature exchange is maximized due to 1) the lack of the ballon effect, 2) the humidity inside the car will decrease faster b/c yo are not introducing outside air which will increase humidity levels (yes, even after ONE pass over the AC the humidity level will be higher than inside air), and 3) cooling the air that is already inside will become more efficient as the temp changes than pulling outside air, cooling it down, and forcing it inside.

Sorry if this does not make sense or seems wordy. How about this explanation: Less humid air feels cooler than more humid air. Having the AC running removes humidity. Using recirc. will remove the humidity faster thus making it feel cooler quicker. Re-cooling the same air that has been mixed with the warmer air inside the cabin is much more efficient than pulling the outside air which is gonna be hotter than the cooled inside air (yes the outside air might be cooler at first, but road heat, fumes, other cars, and the interior being cooled down negates this quickly). As for the ballon effect: Your cabin is sealed to be as air tight as possible. There are some leaks, but not a lot. If you pull outside air in, you are trying to fill the already full cabin with more air. The system can only push so much in at a time (thus why in the early days of AC w/o the recird. system you would roll down your back windows to let the hotter inside air escape while the cold air was blown in up front). Now with recirc, you maintain the same air pressure, more air can be moved through the cabin, and the temp. can be controlled much faster. I am all for having some fresh air, but when it comes to cooling/heating and efficiency, recirc. can not be beat right now. Besides, is that "fresh" air from outside with the fumes/smells/toxins really better than cleaning the inside air?

Just my 5 cents ...
 

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As to #1, recir is way more efficient than fresh air. Why? Well lets take a little tour.

If the outside air is 85 and your inside air is 105, cooling off that air will be a lot faster than cooling off the outside air and forcing it inside. Recir does just what it says, it take air from the inside and passes it back through the AC/Heat system and blows it back into the cabin. If you are taking "fresh" air in you will 1) have more contaminants from outside (esp. on the road) into the filter and cabin and 2) have a less efficient system due to it trying to blow air into an already full space (i.e. ballon effect).
Just my 5 cents ...
That's fine IF you have the A/C on. In my case, I do not. Control is set on AUTO which does not engage the A/C,. The A/C is set to OFF. Also I leave the moonroof cracked open (tilted) while parked. So what happens is I get into a car with a much higher inside temp than out side and the recirc kicks in recirculating the hot air that is in the vehicle instead of pulling in the cooler outside air. It doesn't do this first thing in the morning. The fan usually runs at its lowest speed until the sun warms up the interior to the point where the AUTO setting increases the fan speed and starts to pull in the cooler outside air. Why would it not do the same after sitting parked in the sun for a period? I constantly end up having to deselect the recirc button and put the window down as I drive away. BTW, I rarely use the A/C. :confused:
 

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Wasn't implying anything.

Just clarifying.

The one thing Toyota owners have to deal with is "Toyota knows what is best for you" engineering practice.

They make it difficult for an owner to make custom changes to how things work and it took a while for them to install a switch to allow the owner turn off VSC when situations call for it.

Installing a PB to turn TC/VSC off involved an ADMISSION that the F/awd system was not functional in the very conditions for which most buyers purchase these systems.

Toyota builds a great product but they seem to feel owners are idiots and need a nanny to protect them.
Nanny's...

I don't think I would EVER turn off VSC even with the capability.
 

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As to #1, recir is way more efficient than fresh air. Why? Well lets take a little tour.

If the outside air is 85 and your inside air is 105, cooling off that air will be a lot faster than cooling off the outside air and forcing it inside. Recir does just what it says, it take air from the inside and passes it back through the AC/Heat system and blows it back into the cabin. If you are taking "fresh" air in you will 1) have more contaminants from outside (esp. on the road) into the filter and cabin and 2) have a less efficient system due to it trying to blow air into an already full space (i.e. ballon effect).

Internal air pressure stays the same and air temperature exchange is maximized due to 1) the lack of the ballon effect, 2) the humidity inside the car will decrease faster b/c yo are not introducing outside air which will increase humidity levels (yes, even after ONE pass over the AC the humidity level will be higher than inside air), and 3) cooling the air that is already inside will become more efficient as the temp changes than pulling outside air, cooling it down, and forcing it inside.

Sorry if this does not make sense or seems wordy. How about this explanation: Less humid air feels cooler than more humid air. Having the AC running removes humidity. Using recirc. will remove the humidity faster thus making it feel cooler quicker. Re-cooling the same air that has been mixed with the warmer air inside the cabin is much more efficient than pulling the outside air which is gonna be hotter than the cooled inside air

(yes the outside air might be cooler at first, but road heat, fumes, other cars, and the interior being cooled down negates this quickly)

"...outside air might be cooler at first.." "...interior being cooled down negates this quickly.."

"...might be..."

These automatic climate controls have the sensors, EXACTING SENSORS, available wherein the system could automatically be in FRESH mode until such time as the incoming cabin air temperature is equal to or slightly below OAT. Hell, it could ven lower the rear windows slightly until such time, and even allow for extended time for the interior surfaces to be cooled to near OAT.

Those are pretty damn good arguments for over-riding the recirc function "at first".

As for the ballon effect: Your cabin is sealed to be as air tight as possible. There are some leaks, but not a lot. If you pull outside air in, you are trying to fill the already full cabin with more air. The system can only push so much in at a time (thus why in the early days of AC w/o the recird. system you would roll down your back windows to let the hotter inside air escape while the cold air was blown in up front). Now with recirc, you maintain the same air pressure, more air can be moved through the cabin, and the temp. can be controlled much faster. I am all for having some fresh air, but when it comes to cooling/heating and efficiency, recirc. can not be beat right now. Besides, is that "fresh" air from outside with the fumes/smells/toxins really better than cleaning the inside air?

Just my 5 cents ...
Yes, there are some instances wherein modern day vehicles are just plain TOO WELL SEALED. That's probably why most owners manuals still advise lowering the windows for the first few miles of driving when the cabin has been overheated above ambient. And keep in mind that it isn't just the cabin atmosphere that is overheated, all of the surface material might well also be above ambient.

So it is PATENTLY FOOLISH to ask the A/C to un-necessarily cool the over-heated interior atmosphere.


And, somewhat regretably, NetWhiz makes a good point.

If the A/C were operated before the car was parked fully closed up in the hot sun then the cabin humidity is likely to be unusually high. All of the condensate accumulated during the previous operation does not drain out of the plenum. A goodly portion will simply evaporate into the closed cabin.

Making yet another good argument for lowering those rear windows "..at first.." (automatically..??) during the first few minutes of your drive.
 

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2008 Highlander Base
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I don't think I would EVER turn off VSC even with the capability.
I'm assuming you've never been stuck in deep sand, ice, or an algae-slicked boat ramp? Other than finding someone to tow you out, turning off VSC/TRAC is the only way to extricate yourself.
 
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