Cooled seats not cooling

[GT Pony]

The thermoelectric devices (TEDs) can be deceptive. When you apply a voltage across them, one side heats up and the other side cools. Reverse the voltage and the sides switch. If you set it to cool in a 55f car with 55F air, it will cool the cool side to less than 40F.

Here's where it gets ugly. Imagine the car is at 110F and you turn on the cooled seat (which has TEDs for the bottom and back). It starts blowing 95F air. Very quickly, the hot sides heat up from their own heating. Worse, the heat from the seat bottom TED rises and heats the seat back TED. If the seat back TED gets up to 120, its blowing 105F air, etc.

My theory is that the things were designed for the Fusion (which has AC ducts under the front seats to serve the rear seat passengers) where the underseat ducts help cool the TED hot sides and thus prevent the situation of runaway heating when you want cooling.

Could very well be that is one reason they stop cooling shorty after being turned on. If so, maybe they would do better if the whole cabin temperature was brought down significantly with the AC on recirculation before turning on the seat coolers.

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[papinist]

I gotta say that so far my seats seem to cool enough, though the highest temp I've had so far is 55F... bottom cools a lot quicker and more than the back though, and the back seems to only be the lower half...? anyhoo, first cooling seats I've ever tried - it's a little bit creepy to feel that "frost" come up from down below

My friend, you are in Norway... you probably don't even need A\C

 

[ctlaw]

Could very well be that is one reason they stop cooling shorty after being turned on. If so, maybe they would do better if the whole cabin temperature was brought down significantly with the AC on recirculation before turning on the seat coolers.

But consider the environment under the seat.

Air is not easily getting there. it will be the last place to cool down. But, as the car warms up, heat from the exhausts will heat the floor and possibly overpower any incidental cooling from cabin AC.

 

[gojensen]

My friend, you are in Norway... you probably don't even need A\C

Oh I do everytime it goes above 68'F (20C) ... which is... sometimes? Then again, I'll be dropping my top for that so no worries :cheers:

 

[Sc00ter]

Oh I do everytime it goes above 68'F (20C) ... which is... sometimes? Then again, I'll be dropping my top for that so no worries :cheers:

Sounds wonderful. Are you guys left-hand drive over in Norway, like we are in the US? :ford:

 

[Cobra Jet]

Just curious - has anyone prestarted their vehicle w/ AC on AND the seat cooling set to MAX - then got in the car to go where ever for a ride?

If the interior vehicle temps are high due to exterior weather or from baking while sitting for a period of time in direct sunlight - and the owner just hops in w/o prestarting the car and AC or seat coolers are off - the combination of a hot interior (seat back) is going to be exasperated by the human body resting/pressed up against it. Turning on the seat cooler at that point is going to feel like it does not make a bit of difference...not after your back has already now absorbed the heat from that seat that's been baking all day long.

I'm just curious to know if anyone has precooled their car first if they have any significant differences.

For those that do not know (at least this is true for my 2016):
You can set the seat cooling/heating function for the remote start to "auto". By doing so, if hot outside and the car is remote started, the seats will automatically click on to cool (and same is true if it's cold out and vehicle is remote started, the seats will click on to heat). If this function is set to "last setting", that means if the seats were not left on by the user when car was turned off last, the seats will not click on when car is remote started (same is true with HVAC system).

 

[Darko66]

Well it cooled down here quite a bit, so couldn't do any truly useful testing.

I did sort of try to see what would happen with a remote start and confirmed at least that the seat coolers do indeed turn on if they are set to do so. The car wasn't hot enough to really see much though. I think, realistically, that the AC blowing on the seats in a really hot car does much more in a remote start than the seat cooler will. Of course, without at least some kind of fix for the air intake be it Ford's iffy fix or something like I or droidjunky and possibly others have done, the back cooler is fairly useless in all instances.

I did have very good results on my way in today. Car was in garage and started at 79° and both blowers stayed around 55° for the 15 minute trip. I borrowed a Seek Thermal camera that plugs into my iPad and took a pic a couple minutes after I'd gotten out of the car with the car and seat coolers still running. If I'd had my act together, I would have been ready to take the photo as soon as I'd gotten out. The seat cushion is a little cooler than the back, but the back is pretty close. I was trying to get the whole seat in, so the hot area on the left side is the side pillar/windshield.

I'm working on an idea to make a custom intake tube that will be flat enough to allow the seat to be properly closed up as well as go all the way to the front of the seat. It might even have a little insulation. I have to wait for the materials to come and then will hope it turns out a success vs a disastrous failure.

I'll do a timelapse with the thermal camera once it's warmed up again and I have the chance.

 

[GT Pony]

^^^ "Cool" IR photo. Assuming the seat cushion is at 66 F (photo should be rotated 90 deg CCW).

 

[Darko66]

^^^ "Cool" IR photo. Assuming the seat cushion is at 66 F (photo should be rotated 90 deg CCW).

Yes, sorry, the photo was upright when I previewed the post.

fixed it, maybe?

 

[ctlaw]

^^^ "Cool" IR photo. Assuming the seat cushion is at 66 F (photo should be rotated 90 deg CCW).

Darko66,

Thanks for your work on this. The photo reminded me of something. In general the seat bottom cooler is weak; whereas the seat back cooler is almost nonfunctional or even counterproductive.

We've mostly been talking about mechanical solutions involving airflow. Is there anything that can be done electronically?

My thought is to electronically shift the bias toward the seat back. If I recall correctly, one issue is that heat from the hot side of the seat bottom TED is heating the hot side of the seat back TED. if we drop power to the seat bottom TED by say 50%, will that improve performance of the seat back TED?

 

[Darko66]

Darko66,

Thanks for your work on this. The photo reminded me of something. In general the seat bottom cooler is weak; whereas the seat back cooler is almost nonfunctional or even counterproductive.

We've mostly been talking about mechanical solutions involving airflow. Is there anything that can be done electronically?

My thought is to electronically shift the bias toward the seat back. If I recall correctly, one issue is that heat from the hot side of the seat bottom TED is heating the hot side of the seat back TED. if we drop power to the seat bottom TED by say 50%, will that improve performance of the seat back TED?

Well, the primary problem with the seat back cooler is the airflow, but I do think software tweaks could possibly help. Ford would have to be willing to either update the control module or send whatever codes needed. I think you could leave the seat cushion voltage (amperage?) alone and just up the back a little. Although it is possible that it's already set at the ideal voltage. The more power you give it the more heat is generated, so it might be counterproductive.

What I think it really needs is a higher fan speed to both push more of the cool air through the seat and to cool off the hot side of the TED. I had run across something that talked about a fix for cooled seats in an older Ford, but I haven't been able to find it. The fix was to send a command to the control module - "max fan" I think. Although it's possible we are already pushing the fan to its maximum. I will keep searching for that description of the fix and will share if I stumble upon it again.

 

[Darko66]

Old Expedition TSB

This wasn't what I'd seen before, but essentially what I was talking about. Not sure it's still applicable to today's systems.

TSB 07-22-4

11/12/07

POOR SEAT COOLING PERFORMANCE - BUILT BEFORE 7/16/2007
FORD:
2007-2008 Expedition

LINCOLN:
2007-2008 Navigator

This article supersedes TSB 07-15-5 to update the Service Procedure.
ISSUE
Some 2007-2008 Expedition and Navigator vehicles built before 7/16/2007 and equipped with climate control seats, may exhibit poor cooling performance in the seat.

ACTION
Follow the Service Procedure steps to correct the condition.

SERVICE PROCEDURE

Verify there are no diagnostic trouble codes (DTCs) and that the thermal emitting device and fan assemblies are working properly. Then use IDS to select the Maximum Output Mode. This will increase fan speed to provide quicker cooling.
1. Using IDS (equipped with release B51.5 or higher) normally ID the vehicle.

2. Select "Toolbox" at the top of the screen.

3. Select "Module Programming" from the menu.

4. Select "Programmable Parameters".

5. Select "Climate Control Seats".

6. Select "High Cool Blower Voltage" to change setting.

7. Select "Maximum Output Mode".

8. After the preference has been successfully changed, verify that the seat fan assemblies are operating according to the new setting.

WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
IMPORTANT : Warranty coverage limits/policies are not altered by a TSB. Warranty coverage limits are determined by the identified causal part.

OPERATION DESCRIPTION TIME

072204A 2007-2008 0.3 Hr.
Expedition/Navigator
Vehicles Built Before
7/16/2007: Check For
DTCs, Then Change The
High Cool Blower Voltage
to Maximum Output (Do
Not Use With 12651D,
12651D4)

DEALER CODING

CONDITION
BASIC PART NO. CODE
14C724 42

 

[Cobra Jet]

Out of curiosity - could the actual fan be upgraded or replaced with another fan that is higher output? Not necessarily a "Ford" fan unit, but say one that is known to perform better?

 

[Darko66]

Out of curiosity - could the actual fan be upgraded or replaced with another fan that is higher output? Not necessarily a "Ford" fan unit, but say one that is known to perform better?

Well I imagine you could replace the whole blower unit with any other somewhat recent Gentherm/Amerigon one like one from a previous generation F-150, but it probably wouldn't squeeze into the back of the seat.

I'm just guessing, but I assume if you could find a replacement for just the little squirrel cage fan itself, you could swap it. Not sure how well incased the fan is in the shell though.

Although it might not make much difference. I assume it probably is a highly efficient fan already and you can't put a larger one in. The fan would still be receiving the same voltage, so it would have to have more cfm per volt, I guess.

I believe the procedure in the old Expedition TSB I posted is just boosting the fan voltage a little. Forgot to mention that.

 

[Rich of So Cal]

TSB date is 9/22 and says this "may affect some 2015/16 Mustangs." So I would surmise if your build date is after 9/22 you may be good, and if it's much before that, you may be affected. Hard to know from what they are saying. The squealing brake TSB had a hard date in it, all cars built before April something, as I recall. This one is not so helpful.

I can't believe I finally reached the end of this thread!

I had my car seat cooling checked a couple days ago and got the same response as others...normal operating status.

They also told me they checked and found no tsbs! I didn't know about the one from last September, at the time. I have the same problem as others. Minimal cooling in the seat bottoms, and after while it blows hot thru the back. Now, with the extreme heat we have been having, I understand why it is doing that later in the day, but checked as normal at the dealer 2 mornings ago.

This thread went quiet suddenly in May? Has everyone gotten their seats fixed or what???

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