Completely disable auto HVAC recirc?

[Kamuelaflyer]

@Ford Motor Company just put the recirc button on the "home" screen below the HVAC drawer button. There are two buttons stacked one on top of the other on the other side of the volume knob so it's feasible to put two buttons on the right side.

If you have a touch screen, at a minimum it's your responsibility to minimize touches (and waiting for a response, for that matter). Makes me wonder if the lawyers considered how far the car goes down the road while a user waits for the HVAC screen to appear?

Proper usage is not to stare at the screen. Tap the icon that bring up what you need, go back to watching the road and driving. Repeat again if necessary. Always return to driving after each tap. When the screen you need is up, in this case the full HVAC screw, tap rye ici you need once. Go back to watching the road, then glance at the screen to confirm the system is where you want it. Repeat as needed until everything is how you desire.

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[DigitalN]

Meanwhile, I have little to no issues with fogging in the same conditions and colder? Also on the latest HVAC software. I use 20ºC AUTO 2 as my preferred setting (I leave it in AUTO 99% of the time).

The ONLY time I have issues with fogging is when I slow down (<60 kph), above that speed it seems the outside air damper never closes. When I do slow down, the fogging only lasts for a minute or two before clearing by itself.

Also, I'm typically just one person in the car with minimal snow on my boots.

Do you think you have a lot of moisture in the car, usually drive below 60 kph, or park in heated garage that might cause a lot of melt water or trigger the AC to run during remote start?

I want to understand why some people have a lot more fogging issues than others.

Sure I can provide some context!

We usually drive around at 21.5 or 22C. There is typically 2 adults and a child in the car at a time.

I've tried auto 2 or 3, but the fan never ramps up enough to keep the cabin warm, or the fogging becomes brutally difficult to control so I have to manually control the fan to 5 or 6 just to delay the fogging and keep the fan noise to a reasonable amount.

This happens going down the highway, but it's even worse around town in traffic on regular roads in stop/go traffic. There is no way to just let the auto HVAC do it's thing, the windows fog up so much it becomes dangerous to drive. You absolutely need to press the defrost button to clear the windows before going back to normal.

We do park in a heated garage overnight, the floor mats are clear without water, and it happens on extended drives. Like we'll have been out of the garage for hours and it still happens.

 

[Kawika]

I just hit fan and roll the control to off and it does not come on by itself.If you leave the system on, it will revert to previous setting next time I drive.If I use a warm up, it will stay in that mode until I hit the fan and roll the control to off.

 

[Mach-Lee]

Sure I can provide some context!

We usually drive around at 21.5 or 22C. There is typically 2 adults and a child in the car at a time.

I've tried auto 2 or 3, but the fan never ramps up enough to keep the cabin warm, or the fogging becomes brutally difficult to control so I have to manually control the fan to 5 or 6 just to delay the fogging and keep the fan noise to a reasonable amount.

This happens going down the highway, but it's even worse around town in traffic on regular roads in stop/go traffic. There is no way to just let the auto HVAC do it's thing, the windows fog up so much it becomes dangerous to drive. You absolutely need to press the defrost button to clear the windows before going back to normal.

We do park in a heated garage overnight, the floor mats are clear without water, and it happens on extended drives. Like we'll have been out of the garage for hours and it still happens.

If I had to guess why you have worse fogging, it's probably because you have three people in the car. At -20ºC outside, it only takes about 4% relative humidity in the cabin to produce window fogging. At -30ºC, it only takes 1.5% relative humidity (these are extremely low levels). Your breath alone can easily raise the humidity in the cabin to 10% or more. You also emit moisture through your skin. Basically each person in the car is acting like a humidifier.

In order to fight the moisture and keep the relative humidity below 5%, you need a lot of fresh air, which is too cold to fully heat. That's why you end up with no heat trying to fight window fogging.

FYI, for more cabin heat you actually want the blower speed as slow as possible, like around speed #2. When you turn up the blower you are also exhausting more warm cabin air, essentially all the warm air gets blown out the back of the car so you cool down. It's very important to minimize fan speed for heat retention. That's why I recommend using AUTO 1 or 2 setting in externe cold and only using defrost as needed.

Because you act like a humidifier, it's best to use remote start to warm up the car and glass as much as possible before you get in it.

 

[rugedraw]

@Mach-Lee with the Bill Nye the Science Guy response FTW. OP is gonna have to drive around with DampRid in his car during winter.

 

[Mach-Lee]

@Mach-Lee with the Bill Nye the Science Guy response FTW. OP is gonna have to drive around with DampRid in his car during winter.

Well, wait 'till you see this: Window Fogging Analysis

Not the first time I've been called BNTSG...

 

[rugedraw]

Well, wait 'till you see this: Window Fogging Analysis

Not the first time I've been called BNTSG...

I flippin' love Florida.

 

[DigitalN]

If I had to guess why you have worse fogging, it's probably because you have three people in the car. At -20ºC outside, it only takes about 4% relative humidity in the cabin to produce window fogging. At -30ºC, it only takes 1.5% relative humidity (these are extremely low levels). Your breath alone can easily raise the humidity in the cabin to 10% or more. You also emit moisture through your skin. Basically each person in the car is acting like a humidifier.

In order to fight the moisture and keep the relative humidity below 5%, you need a lot of fresh air, which is too cold to fully heat. That's why you end up with no heat trying to fight window fogging.

FYI, for more cabin heat you actually want the blower speed as slow as possible, like around speed #2. When you turn up the blower you are also exhausting more warm cabin air, essentially all the warm air gets blown out the back of the car so you cool down. It's very important to minimize fan speed for heat retention. That's why I recommend using AUTO 1 or 2 setting in externe cold and only using defrost as needed.

Because you act like a humidifier, it's best to use remote start to warm up the car and glass as much as possible before you get in it.

Yeah more people is obviously more humidity. I'll try Auto/1/2/3 a bit more but 1 or 2 is always way too far off of the target temp because of the low fan speed (on top of condensation issues). Auto 3 has the higher fan speed which keeps the fog away longer, but it's still unavoidable.

Understood that a higher fan speed means a higher energy cost from excess heat being dumped outside. I'd rather have a clear windshield and less range than be driving a 5000lb car that I can't see out the windows of though.

I think my problem is I've never had issues like this in any other car. Literally any other car I've ever owned has never automatically turned on the recirc when I specifically don't ask for it, other than when you press Max A/C. I've owned upwards of 30 different cars from varieties of makes and models.

Take my 2008 Mercedes E320 for example. I would set Auto at 21.5C, set it to defrost and foot... the car takes care of everything. It keeps the fan low when the engine is cold, speeds it up when it warms up, and if the cabin temp goes down it speeds the fan up. I seriously don't even touch it all winter as it's that good. I feel like in my Mustang I constantly need to baby the HVAC to keep it at a comfortable temp while being able to see out the windows and not have the fan so loud I can't hear my kid in the back. It's a bit frustrating as it's such a high tech vehicle but the HVAC is such a pain.

Obviously it's ICE vs electric but the fact of the matter is the fog wouldn't start if it didn't start re-circ out of the blue. It's comes on and my windows are fogged within 20 seconds, and then I need to start the defog setting where the temp sets to max, fans on max, and window vents only until it clears up. If I don't do this, the area I can see out of the window is dangerously small, if there is one. Once it's clear I turn it off so I can talk with my family, and I start the dance again within 10 minutes. It's incredibly annoying

 

[gavine]

If you super-clean the inside of your windows, they will be much less-likely to fog-up.

 

[DigitalN]

This has always been a pet-peeve of mine. I have been meaning to go into the HVAC with FORScan and disable everything that has to do with the recirculation strategies to see if it just stays on what I set it to, but I have yet to actually do it to see what happens. Part of the reason is, if you go to the FORScan spreadsheet under the HVAC and control F and search for "recirc", there are SO MANY different kinds of recirculation strategies, I don't even know where to begin in terms of disabling them.

The one thing I have seen there that may just prevent the recirc actuator from ever working is this:

This has always been a pet-peeve of mine. I have been meaning to go into the HVAC with FORScan and disable everything that has to do with the recirculation strategies to see if it just stays on what I set it to, but I have yet to actually do it to see what happens. Part of the reason is, if you go to the FORScan spreadsheet under the HVAC and control F and search for "recirc", there are SO MANY different kinds of recirculation strategies, I don't even know where to begin in terms of disabling them.

The one thing I have seen there that may just prevent the recirc actuator from ever working is this:

My truck shows a 2 there which means no 3rd row actuator (makes sense) and it does have a recirc door actuator WITH feedback. No sure what "with feedback" means, but I have thought of going in there with FORScan and chaning it to a 0 to see if the recirc actuator just gets disabled permanently while recirc is on and just stays on.

I finally got ForScan working and tried to get into these settings, odd that there is no HVAC section for my MachE. There is PCM, BodyCM, and obviously some others too but no HVAC. Interesting that there is one for the F150 however.

 

[rugedraw]

I finally got ForScan working and tried to get into these settings, odd that there is no HVAC section for my MachE. There is PCM, BodyCM, and obviously some others too but no HVAC. Interesting that there is one for the F150 however.

This is something I would say is very safe to play with as long as you make a back-up of the HVAC ab data first jic.

 

[DigitalN]

This is something I would say is very safe to play with as long as you make a back-up of the HVAC ab data first jic.

Indeed I will do this, I just need to sort out how to actually access the HVAC module first. I only have these ones.

I've configured modules on Mercedes and VW before so I know there are risks, but I'm hoping that I can at least find the settings on my car specifically.

PCM (As Built)
PCM

SOBDMC (As Built)

BECM (As Built)

SODR (As Built)

SODL (As Built)
SODL (Configurable)

CMR (As Built)

CCM (As Built)
CCM (Configurable)

ABS (As Built)
ABS (Configurable)

PSCM (As Built)

BdyCM (As Built)
BdyCM (Configurable)

BECMB (As Built)

GWM (As Built)

IPMA (As Built)
IPMA (Configurable)

SODCMD (As Built)

SODCMC (As Built)

BCMC (As Built)

 

[rugedraw]

Indeed I will do this, I just need to sort out how to actually access the HVAC module first. I only have these ones.

I've configured modules on Mercedes and VW before so I know there are risks, but I'm hoping that I can at least find the settings on my car specifically.

PCM (As Built)
PCM

SOBDMC (As Built)

BECM (As Built)

SODR (As Built)

SODL (As Built)
SODL (Configurable)

CMR (As Built)

CCM (As Built)
CCM (Configurable)

ABS (As Built)
ABS (Configurable)

PSCM (As Built)

BdyCM (As Built)
BdyCM (Configurable)

BECMB (As Built)

GWM (As Built)

IPMA (As Built)
IPMA (Configurable)

SODCMD (As Built)

SODCMC (As Built)

BCMC (As Built)

That is weird. I assume this is the first time you plug forscan in, so this is based off of a fresh scan. You may need to email FORScan support with your VIN. It could be a database issue on their side.

 

[DigitalN]

That is weird. I assume this is the first time you plug forscan in, so this is based off of a fresh scan. You may need to email FORScan support with your VIN. It could be a database issue on their side.

Yes I've never used it before, this is my first Ford. I'll reach out then and see what they say. Cheers!

 

[Vice]

Sure I can provide some context!

We usually drive around at 21.5 or 22C. There is typically 2 adults and a child in the car at a time.

I've tried auto 2 or 3, but the fan never ramps up enough to keep the cabin warm, or the fogging becomes brutally difficult to control so I have to manually control the fan to 5 or 6 just to delay the fogging and keep the fan noise to a reasonable amount.

This happens going down the highway, but it's even worse around town in traffic on regular roads in stop/go traffic. There is no way to just let the auto HVAC do it's thing, the windows fog up so much it becomes dangerous to drive. You absolutely need to press the defrost button to clear the windows before going back to normal.

We do park in a heated garage overnight, the floor mats are clear without water, and it happens on extended drives. Like we'll have been out of the garage for hours and it still happens.

Hi,
I experience the same but I'm only one in the car and my car is parked outside but I also have to go to manual and fan 6 to fight the fog

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