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Has anyone had a problem with the AC/Heater. Specifically when I turn on the heater the FRESH air vent turns on automatically and if I press the RECIRCULATE it turns on the A/C, but I do not want the A/C to turn on. I want RECIRCULATE with HEATER only.
 

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I noticed this too.. I don't think there is a way to change it..

(like you I want to have the heat recirculated..)
 

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The A/C comes on when recirculation is switched ON to prevent condensation from building-up on your windows. Since the recirculation function does not allow fresh air to enter the vehicle and stale air to ventilate out, water vapor (from your breath, skin, or even damp clothing) can condense on cold windows, fogging them. The A/C 'dries' the air, so to speak. You will notice it is also activated when you turn on the front window defogger.

Yes, kicking up the heat alone will eventually defog the windows, but the A/C is faster, albeit at the cost of running the compressor (and using up additional gas in the process).

If you have ever seen other drivers motoring around with heavily fogged-up windows, you can bet they have their recirculation turned on (without A/C).
 

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It should be noted that even with recirculated air, SOME fresh air is coming into the vehicle.

And yes, you cannot recirculate without having the A/C "on". Even when it is "on", it is not necessarily COOLING the air. You can have your climate control set for 80 degrees and the A/C on... it will still be heat.

A/C Off is good for when you really only want heat, like when you are heating up your car in the morning and want it on full blast.
 

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This is kind of off topic but it kind of relates to the AC being automatically switched on. Does anyone notice that even in very cold weather, the AC compressor engages under the fresh air mode? For example, its 30 degrees outside, and I start the car. I turn on the climate control to "auto" and 70 degrees. I hear the click of the AC clutch engaging. Now why would the AC turn on at 30 degrees? I know its not 70 inside the vehicle! I realize the AC compressor probably cycles on and off as needed, but I am rather annoyed that it turns on EVERYTIME you put the system into auto mode. I know you can turn it on or off manually, but my point is that it should not engage when its freezing cold outside.
 

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Discussion Starter #6
I appreciate all the input and thanks. I should send an email to Nissan and ask them about this little quirk, it not so much me but my significant other.
 

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The behavior is by design. I completely agree with you. I've been trying to find a away to over ride the AC auto turn on feature. I hate it. Many times I just want to recir temp and do not need the AC to run. The only solution I'm thinking about is to run a switch from the compressor to the interior and I can manually cut power to the compressor.
 

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Most car manufacturers have made the heating system turn on the a/c when defrost mode is selected. The main reason is to run the compressor once in a while. Not using it at all (compressor) during the sometimes very long winter will lead to problems when you do need it. The recirculate override in heat mode is a blessing in disguise IMHO. As already mentioned above, running recirculate in heat mode will fog all your windows up very quickly. Personally I cannot see any benifit whatsoever in using recirculate in heat mode. Yes the interior will heat up slightly faster in recirculation but what's the point if you can't see where your headed.
 

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Snowride said:
Most car manufacturers have made the heating system turn on the a/c when defrost mode is selected. The main reason is to run the compressor once in a while. Not using it at all (compressor) during the sometimes very long winter will lead to problems when you do need it. The recirculate override in heat mode is a blessing in disguise IMHO. As already mentioned above, running recirculate in heat mode will fog all your windows up very quickly. Personally I cannot see any benifit whatsoever in using recirculate in heat mode. Yes the interior will heat up slightly faster in recirculation but what's the point if you can't see where your headed.
I use recirc when the car in front of me is 20 years old and is belching noxious exhaust that I can smell. In such a situation, I don't care if it wastes gas that the AC is automatically on, its better than suffocating on gas fumes. This is unrelated to the heater, but using recirc during hot weather places less strain on the AC.
 

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If the car in front of you is spewing noxous fumes, the best bet is to turn off the entire HVAC system. I imagine that closes all outside vents and basically seals off your interior... I could be wrong. But it does disengage everything.. fans.. AC.. heater.. etc.

When you've passed the ugly exhaust fumes, kick 'er back on.
 

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Doombringer said:
If the car in front of you is spewing noxous fumes, the best bet is to turn off the entire HVAC system. I imagine that closes all outside vents and basically seals off your interior... I could be wrong. But it does disengage everything.. fans.. AC.. heater.. etc.

When you've passed the ugly exhaust fumes, kick 'er back on.
I'm one of those weird people who get noxious if I don't have ventilation constantly in the car. :rolleyes:
 

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I need the fresh air too.... if you turn off the entire system, you will still get a 75% floor 25% defrost with the fresh air open. I think the system is designed for the average user. In my prev car that did have this type of HVAC system I would cycle the AC every couple of weeks. Do you think these quick AC cycle on the compressor are good for it?

The only solution that I've got so far and I admit it isn't a good one, if I really need to to any manual over rides I do so, but when I want the system back in auto mode I do so with the engine off and then turn the AC off too so the next time I use it the system (without turning it off) I have full auto without the AC running.

If anyone knows of a good way to manual override the AC on feature please post. I wish the fuse to the compressor was in the interior so I could just tap into that line withouth having to get into the engine side of things.
 

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Gonzo or anybody else that wants to change the operation of the HVAC system. If you do that, you can kiss your warranty goodbye on the whole system.

As someone else stated. There is a secondary reason for the A/C to kick on.......the A/C system has OIL in it that keeps the bushings and seals lubricated as well as the compressor......so it needs to be operated every once and a while to keep the system "fresh".
Also, as stated, using the A/C while heating dries out the air to keep it from fogging up your windows, although it STILL HEATS with a slight loss of efficency while saving your A/C system from breaking down.
Its best to just know how it works and that it is in your best interest to just leave the system to how it is.

Just an FYI...
Chez
 

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Thanks for the info chezman, I'll take care of exercising the system myself. I think that if I run it for 15-20 minutes is better than these little 2 seconds on/off. I just want to turn of the outside when behind a smelly car for a few minutes. The car will not fog up that fast. I agree and us freeair 99% of the time. I can remember when I was young (12 years old) and my dad was dring to defrost the car with recir off. He didn't believe that drawing in fresh air would help.

Silly looking at drivers in the winter (outside humidy 20%) and their windows are fogged. Wouldn't a normal person notice and think that "why am I the only one on the road with fogged windows and the air is so dry... I know I'll open the fresh air vent"

People can be so dumb sometimes.
 

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Yeah, it would nice to be able to recirc the air temporarily such as when there are noxious fumes outside the car. I mean, it would be fine if the HVAC system turned on the AC when you recirc if it's in Auto mode- if you choose Auto, you should be willing to accept what it thinks is best. But what is is about "Manual" that they don't understand? I guess that's why there's no "manual" mode just an "auto" on and not-so-on (can't really call it "off")

Okay, I'd be fine with the recirc automatically turning on the AC when you hit the button, but it should allow you to at least turn off the AC afterwards. That's like my other car- hit defrost and it turns on the AC, but (for example) if it's a cold humid night, I can turn on the recirc and turn off the AC to heat up the windshield quickly so it doesn't get condensation on the outside.

On another note, another annoying thing about the recirc and AC is the blast of cold air when you first turn it on (the recirc, I mean). Wouldn't it be better for the recirc to crank up the heat while turning on the AC?

If it's summer and you turn on the recirc and you didn't have the AC on already then the heat wasn't that bad to begin with. If it's winter then you've got the heat on and certainly don't want the blast of cold air. And the recirc doesn't necessarily have to crank the heat all the way, just roughly enough the offest the AC.

Yeah, and with a bit more programming they could have the recirc compare the outside air temp with the thermostat and crank the heat up or down accordingly, but I guess that's too much to worry about for a transient condition anyway- eventually the climate control will figure things out and get the air blowing out the vents to the correct temp.
 
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