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Mazda6 Interior & Passenger Comfort Issues

19 messages,  Last post on Apr 08, 2013 at 10:17 PM

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What is this discussion about? Mazda MAZDA6, Heating / Cooling, Hatchback, Sedan, Wagon

    

Messages Page 2 of 3

#3 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [rswafford] by wwest

Jul 22, 2011 (9:53 am)

Replying to: rswafford (Jul 21, 2011 3:11 pm)
You now have a DEFECTIVE climate control system.
 
Modern day climate control system design is as much about PREVENTING occupant discomfort as they are about promoting comfort. Almost ALL modern day climate control systems MODERATE the heating and/or cooling mode such that the cabin occupants are not discomforted by EXTREMES.
 
Set the temperature setpoint to 70F on a HOT sunshiny day and you will get fairly COOL system outflow initially, until the cabin air, atmosphere, is lowered to, say, 75F, and then the outflow will be moderated to maybe as high as 60F. Once the cabin atmosphere subsequently reaches within a degree or 2 of the 70F setpoint it might be moderated to 66-68F, just (barely) enough to hold the cabin air temperature at a relatively constant 70F.
 
In my '01 F/awd RX300 if I wish to WARM up the cabin QUICKLY starting out on a cold morning I MUST set the temperature setpoint to the highest temperature (85F). Otherwise the climate control system will moderate the heat level of the system cabin outflow such that occupants are not unduly discomforted.
 
The same is true of simple heating and/or cooling, once the cabin temporature has been raised to nearby your temperature setpoint, or lowered to nearby for cooling, the system will "moderate" the system outflow temperature such that the occupants are not discomforted.
 
Also, once the temperature is within plus or minus a few degrees of setpoint in "heating mode', COLD outside (footwell predominant outlet airflow), it will still switch into cooling mode, cool, coolish, and DRY airflow to your face and upper body.
 
It will still do this, switch into COOLING mode, on the darkest and coldest winter night provided the cabin air temperature is within your setpoint "bandwidth".
 
My advice, and the practice I follow, is to use MAX cooling + recirculate or MAX heating, in accordance with my body needs, and then manually manipulate the blower speed for/as my "comfort" control. If the cabin still becomes too cool for my comfort I then turn off the A/C functionality, disable the A/C compressor clutch.
 
Quite a nuisance to turn the A/C on and off as you travel throughout the day, but more comforting than what those idiot NipponDenso, Denso US, engineers think of as "comfort".
 
Oh, my A/C compressor remains disabled throughout the coolish months.

#4 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [wwest] by mz6greyghost

Jul 22, 2011 (12:43 pm)

Replying to: wwest (Jul 22, 2011 9:53 am)
You now have a DEFECTIVE climate control system.
 
What's so "defective" about it? He jiggled a wire and it started working again, end of story, and it had NOTHING to do with your post about your "defective" climate control.
 
And for the record, modern climate control systems work to the SPECIFIC TEMPERATURE that you set it at, then keep it there. That's what it's supposed to do. If the ambient temperature is dropping from the A/C, and suddenly the air gets slightly warmer, it means the system has reached the temperature that YOU set it at, and it's now maintaining it. It's not "defective", and there's nothing wrong with it.
 
It sounds like you wasted your $$$ on an "auto" temperature-based climate control system on your Lexus, and now wish for a vehicle with the standard rotary knobs for the temperature and fan speed. They still make them.
 
AFAIC, this is my second "auto" climate control system on my '10 Mazda6 (my previous '04 had it as well), and it's works beautifully.
 
On cold mornings, it automatically kicks on the defroster and keeps the fan speed on it's lowest setting until the air gets warmer (usually in under 5 minutes), then gradually increases fan speed, then direction, until the windows are clear and it's at the set temperature. I almost never touch it in the winter months because it does exactly what I'd do.
 
Summer? No problem there as well. In a hot car, the system switches to recirc air and kicks up the fan speed until the car cools off, then slows the fan and maintains the set temperature. Again, as designed.
 
There's nothing "defective" about how an "auto" climate control system works, it's just not for some people used to the rotary dials or levers.

#5 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [mz6greyghost] by wwest

Jul 22, 2011 (8:30 pm)

Replying to: mz6greyghost (Jul 22, 2011 12:43 pm)
"..in a hot car, the system switches to recirc air.."
 
Yet another design FLAW...!
 
It should be pretty obvious to even a beginning HVAC design engineer that switching immediately to recirc is a mistake. The proper procedure would be to leave the system in "fresh" airflow long enough to PURGE the cabin of the atmosphere that is HOTTER than the outside, THEN switch to recirc.
 
I'll bet even your owners manual points out this mistake. It will direct you to lower the rear windows slightly for a few miles in order to purge the HOT cabin atmosphere.
 
Not many of us humans feel very comfortable with dry and cool, coolish, airflow directed to our face and upper body when the human comfort equation indicates the need for HEATING.
 
Toyota and Lexus have recognized the design flaw and there is now a C-best option that prevents the system from going into cooling mode when the human comfort equation indicates otherwise.

#6 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [wwest] by mz6greyghost

Jul 23, 2011 (8:15 am)

Replying to: wwest (Jul 22, 2011 8:30 pm)
It should be pretty obvious to even a beginning HVAC design engineer that switching immediately to recirc is a mistake. The proper procedure would be to leave the system in "fresh" airflow long enough to PURGE the cabin of the atmosphere that is HOTTER than the outside, THEN switch to recirc.
 
That's right, lets allow the super-humid outside air to circulate into the cabin for a few moments while the occupant wants the cooler, DRYER air immediately. That makes sense...
 
The reason why it switches to recirc in the first place is to limit the amount of moisture in the air, as well as being more efficient by reusing the cooler air. Despite the fact that it may be warmer inside a vehicle when first starting out, the air is also not nearly as humid, and it's also something that HVAC engineers DO know.
 
I'll bet even your owners manual points out this mistake. It will direct you to lower the rear windows slightly for a few miles in order to purge the HOT cabin atmosphere.
 
Umm, nope, it doesn't. In fact, if I needed more than 30 seconds to feel at least some cool air coming from the vents, then I'd say the A/C wasn't working at all.
 
So it makes more sense to keep the windows down for a few miles, then kick on the A/C? Umm, no thanks. Since most car trips are no more than a few miles, why bother?
 
Not many of us humans feel very comfortable with dry and cool, coolish, airflow directed to our face and upper body when the human comfort equation indicates the need for HEATING.
 
Actually, the typical "human comfort equation", or whatever name you give it, likes to be at a certain temperature, whether or not it's the winter or summer. That's why you have a thermostat in a home, office, and now in cars, to maintain that temperature, that's all it does. You make it sound like that it goes into full A/C mode when the car reaches the set temperature in the cooler months, and kicks on the heat in the warmer months. That simply isn't the case.
 
Toyota and Lexus have recognized the design flaw and there is now a C-best option that prevents the system from going into cooling mode when the human comfort equation indicates otherwise.
 
Then it sounds like Toyota has addressed a flaw in their climate control system that isn't found in any other maker today.

#7 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [sgrae] by wwest

Jul 23, 2011 (9:02 am)

Replying to: sgrae (Jun 19, 2008 4:34 pm)
"...Another myth.."
 
Most newer automotive HVAC systems, once the cabin ATMOSPHERE, AIR, has reached a point very close to your temperature setpoint, will "moderate" the system outflow temperature to within only a few degrees.
 
Change the setpoint even 2-3 degrees and the system will react by raising/lowering the outflow temperature in order to most quickly reach your new setpoint, and then moderate begins....
 
The radicalness of the outflow temperature swing upon a setpoint change is dependent on several not so obvious factors.
 
1. The OAT, the outside air temperature.
2. Sun's BRIGHTNESS, solar radiation level.

#8 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [sgrae] by wwest

Jul 23, 2011 (9:10 am)

Replying to: sgrae (Jun 19, 2008 4:34 pm)
"..Im not sure what finally fixed the problem.."
 
My best guess is you somehow locked the "blend" door/vane servomotor in the MAX cooling position, no airflow diverted to flow through the heater core so as to moderate the system outflow.

#9 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [wwest] by oldburbnewcx9

Jul 24, 2011 (8:52 am)

Replying to: wwest (Jul 23, 2011 9:02 am)
Everything you said prior to explaining how radical the temperature swings and the obvious factors is exactly how a modern automotive HVAC system should operate.
 
Wow.. I didn't even know that my car sensed the brightness of the sun.

#10 of 19 Re: 2005 Mazda 6, 3.0L - A/C blows too warm, heater blows too cold. [rswafford] by sgrae

Jul 25, 2011 (10:33 am)

Replying to: rswafford (Jul 21, 2011 3:11 pm)
Awesome! Great to hear it helped.
 
My A/C has been working great ever since I jiggled the wires, and I'm never going back under my dash as long as things are working. One wrong touch of a wire could screw up the A/C again.

#12 of 19 Help A/C prob pls! Only 2 mos Warranty Remains! by natb1

Jun 04, 2012 (12:34 pm)

09 Mazda6 S Grand Touring 3.7L
 
Just got the car 1 week ago, & already I need to find what is causing the following. I only have 2 months of factory b-b warranty, and I want to make sure the issue is addressed properly....especially if expensive factory parts are involved! Im thinking this is happening to others:
 
Symptoms:
 
* after 4 hours of drive time, with AC at maximum blower velocity and minimum temperature and NOT on “Auto”.
 
* AC Blower velocity significant reduced.....especially in drivers side.
* AC temperature not even “cool”
* pulled over opened hood while engine running and AC still on.
* The refrigerant line, leading into firewall, was frosted over.
* turned AC off and waited 5 minutes.
* investigated evaporator area under dash
* Water was pouring out of Evap Box, and down onto the floor boards. ( no drain hose? )
* Water was running out onto unidentified electronic control module and wire harness!
* No Protective Loom or Jacket on wire harness either...... 8 \
* Water came into contact with Heater Core OR “High Side (hot side) AC line”, then dripped on passengers feet, burning them.
* water droplets were spitting out of passenger-center vent.
* Next day AC "seems to work"
 
Have only seen mentions of "cooling fan problems" on this car. Could this be the issue? I was driving Highway speeds the whole time....so never say engine temp go up.
Can this cause the refrigerant line to frost over?
 
Someone please point me to another post if it rings a bell.
 
Im trying to avoid being placated with jive nonsense, or worse, for <60 days, when I will fully own the "real" problem with this car. Thank you in advance!

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