2016 AC Issue

[KCSam]

With the high temps here in KC recently, I've finally been running my AC on a more regular basis. Never had any issues with it until this past Saturday.

I turned the AC on and had it set to 75. I noticed the air coming out from the vents was relatively weak. I looked at the mode and realized that the blowing default mode set to head and feet (even though I never set it to feet since I've owned the car). I pushed the mode button to change to head only, and when I did it turned the auto AC setting off and switched to outside area rather than the inside circulation mode. I went round and round with this for about 10 min. Couldn't get the blower for head only while the AC was running. If I wanted the temp set at 75, it made me set for feet as well. The only work around I was able to find was to lower the temp to 72 or below. At that point, it defaulted to head only and removed the foot blower.

Has anyone else encountered this? Never had this issue before Saturday. To make matters even more strange, later that day and into the night, all of my favorite channels were erased!

Saturday was a strange day for the Cx-5..

 

[MikeM.]

That's why I like manual climate control. Turn lefty for cooler, righty for warmer. Other knob is lefty for feet, righty for head. And of course the fan speed knob.

 

[craigo]

My guess would be that 75 is kind of warm for the A/C and its mixing both A/C and a little heat to achieve it. The system likes to direct toward the feet when the heater is engaged on auto (hot air rises) and so there you go.

I typically keep it set to 68 to maintain a steady breeze. I also agree that manual a/c is simpler - you can still use the auto AC system like that if you turn auto off which is as simple as tweaking the fan speed. I think the temperature displayed is, at best, a sort of guided placebo. I bet you won't be able to tell a difference between 72 or 75. Between 68 and 72 the only difference I see is the fan blows slower.

 

[chucky2016CX5]

I just tried it on my 2016 CX5 this afternoon:
I turned the temp up to 76F and change to head, it let me. I cycled thru all the different modes; head, feet, head + feet, and Windshield. No problem there.

 

[MikeM.]

Chucky, I noticed this is your first post. Welcome, and be sure to share your experiences with your new ride!

 

[KCSam]

Turned the A/C on tonight and it defaulted to 75, where I last left it. This time it set the blower to my head solely and not my feet. I didn't fool around with the temp as I was content to have it finally blowing on my head and not my feet.

Not entirely sure what the issue was before, but it seems fine again. Hopefully it remains.

Thanks for everyone's comments/suggestions.

 

[Cis4]

When you change the mode and/or fan speed, you disable the auto climate control. This is why the auto AC turned off. If you want the AC back on, you need to manually turn it on, set your fan speed, set your mode, set outside or inside air only, and set your temperature. If you switch back to auto, you'll only be able to change temp and inside/outside air only, and the auto mode will decide on AC on/off and fan speed.

 

[KCSam]

This morning when I turned it on it was still set at 75, but again, the foot blower was engaged. I moved down to 73 and it switched to head and foot, and then I moved back up to 75 and the head fan was set by itself. The last 3 times I have used the A/C it's been different. Hopefully now I can just drop it down a few degrees where it sets just the head blower and then raise back up. That didn't work the first time, but I guess I'll see what happens the next time I need the A/C.

 

[craigo]

This morning when I turned it on it was still set at 75, but again, the foot blower was engaged. I moved down to 73 and it switched to head and foot, and then I moved back up to 75 and the head fan was set by itself. The last 3 times I have used the A/C it's been different. Hopefully now I can just drop it down a few degrees where it sets just the head blower and then raise back up. That didn't work the first time, but I guess I'll see what happens the next time I need the A/C.

The outdoor air temp in the morning in KC is under 75, so setting the temp to 75 will first direct air to the feet until the cabin warms up. As it warms up, it will start to direct air both, then to head. Sun load will have an effect too. See: http://articles.chicagotribune.com/...conditioning-climate-control-systems-cool-air

 

[KCSam]

The outdoor air temp in the morning in KC is under 75, so setting the temp to 75 will first direct air to the feet until the cabin warms up. As it warms up, it will start to direct air both, then to head. Sun load will have an effect too. See: http://articles.chicagotribune.com/...conditioning-climate-control-systems-cool-air

That was an interesting read. Thank you for sending. Although, this morning (11:30am) the temp was not 75 as you indicated. It was around 85. I'll need to try again when in the 60's or low 70's and see how it functions.

 

[craigo]

That was an interesting read. Thank you for sending. Although, this morning (11:30am) the temp was not 75 as you indicated. It was around 85. I'll need to try again when in the 60's or low 70's and see how it functions.

Here's an interesting and technical simulation of a system showing the many variables: http://www.mathworks.com/help/simulink/examples/simulating-automatic-climate-control-systems.html

One thing I notice though is that it's actually simplified a lot. The compressor will cycle off if the coil is close to freezing, and usually the blower doesn't turn all the way off either because most people like a little breeze. Every system is a little different, but often setting it to the lowest temp (60?) actually just turns it onto "full cold" while 85 will be "full heat". 75 is a bit on the warm side of the dial so it may skew toward keeping it warmer rather than trying to (hopelessly) achieve a perfect setpoint. This is quite unlike how your home A/C works, even though the physical principles of refrigeration are the same.

 

[KCSam]

Going forward, I'll just set it at <=73 and be done with it. That way I don't have to fool around with trying to get the head blower set alone when at a higher temp. (75).