Greetings,

I adjust the AC on my 09 G37x to its lowest temperature 60° then gradually increase up to 75°. The fan speed decreases; however the temperature measure at the air vent seems to be constant ~39°. Should a warmer air blow through the air vent instead of cold air?

Thanks,

 

Wouldn't it be easier to put it into AUTO mode and you set the temp you want? That way, the fan speed and compressor enagement are taken care of automatically.

 

Remember blowing air over skin will lower the perceived temprature so the harder the fan blows the lower the temp. will feel even though the actual wind temp. hasn't changed. Thats why a windy day (wind chill) will feel cooler even though the ambient temp remains the same.

 

Terry,

If the fan speed is decreasing by itself...then he is in auto mode. Personally, I like that a system would blow hot or cold air at lower levels. I like the minimum fan needed to keep the car at the set temp...that way you not getting lots of cool air and a loud fan, but a little cold air to keep it set right.

My altima was the oppisite of the G and in auto mode...the fan was always loudish...like it never lowered to less than 50% of the fan.

BTW: if you keep going up past 75...at some point, the vent will switch to half face/half feet..and the air WON'T be 39 comming out of the vents...keep raising a degree or two...and the air will go to you feet and start comming out warm.

Also, don't forget...75 is still lower than probably what the sensors think the car is at...so unless your driving for 30+ mins, 75 inside on a 75 outside sunny day will result in lots of cold air.

 

I don't know if it is just me, but I find that I change the temperature setting to be comfortable depending on the weather outside (which I have not done on previous cars). It may be because the air temperature from the vents stays cold....

Next time I have it in for service I'll have them check it out, but it is probably just the way the system works.

 

Same here. If it's hot and sunny outside I need to keep it at about 76F, but in overcast conditions I need to drop it to 74F to keep comfortable. It seems normal - the combination of sunload sensor and external temp sensor seems to overcompensate rather than undercompensate.

 

The operation of the auto HVAC is to maintain a set temperature inside the cabin. So whatever you set the temp to is what the vehicle will try to maintain. It will use a combo of blend door adjustment and blower speed adjustment to maintain your desired tempurature. The actual tempurature of the air coming out of the vents doesn't matter. It's the cabin temp. Just as it would be in a home with a thermostat!

 

Thank you all for your valuable comment and input.

This is such a relieve since I thought that I have to make a 4th visit to the dealer for the HVAC issue.