Cooled seats not cooling

[GT Pony]

I have a suspicion that we're missing something important somewhere. If I have some time tomorrow I'm going to begin dismantling and see what I find in there then report back.

I'm going to hit the sack before I convince myself I need to do it right now.

Sounds good ... we all will be interested in what you find!

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[Free Agent]

Edited: Sorry I think I've been off on my guesses so far.

 

[Free Agent]

It is extremely soft. I couldn't really tell if it was getting squashed. It's only held on by tie wraps. I got a fairly decent pic. Would have posted it earlier but apparently my new phone is saving the files too large. Maybe that is the foam Free Agent is stalking about?

Is that rubber duct connected to the BACK of the back seat or to the FRONT of the back seat? Can't tell from that angle, I'm guessing the BACK of the back seat. But the more I look at it I think I'm wrong.

If that is the front then all my guesses are wrong and its the opposite case. And if that is the case these thing absolutely suck because you can put your hand down by the lower unit and all it does is blow hot air. I guess I need to take an actual drive instead of just running the car in the garage and then feel what type of air is coming out that little vent.

 

[Free Agent]

Here's my stab on what I think is going on. In the photo below, the red arrows show the rejected heat, the blue arrows show the cooled air that goes up inside the rubber duct after the fan blows it across the cold side of the Peltier unit and out the back of the seat perforations. The warm spot you feel on the back of the seat is being warmed up by the warm air rising out of the hot side of the Peltier unit.

The yellow arrow shows the thin Styrofoam insulation wall that separates the cold side from the hot side of the Peltier unit. The hot air just rises up and out of the hot side via natural convection, as the red arrows would be pointing in the upward direction based on how the unit is mounted in the seat back.

I think you are on it in this post the more I think about this.

Here's my latest guess (I've been doing a poor job on my other guesses so take this one with a grain of salt).

The fan is blowing air over the Peltier unit/grid. One side is hot the other cool. The rubber duct vents the cool air to the seat back for the upper unit. The hot air blows out right next to it. That hot air then proceeds to warm up that little rubber duct and when sitting in the seats we compress that duct so basically it isn't flowing much cool air at all and getting warmed up by the hot air blowing right on it.

Now as for the lower, I need to see if there is a little rubber duct down there that does the same for the lower unit on the seat bottom.

I think you guys are onto it and I apologize if I've been scatterbrained trying to figure this out.

 

[Droid_Junky]

Is that rubber duct connected to the BACK of the back seat or to the FRONT of the back seat? Can't tell from that angle, I'm guessing the BACK of the back seat. But the more I look at it I think I'm wrong.

If that is the front then all my guesses are wrong and its the opposite case. And if that is the case these thing absolutely suck because you can put your hand down by the lower unit and all it does is blow hot air. I guess I need to take an actual drive instead of just running the car in the garage and then feel what type of air is coming out that little vent.

The rubber duct is pointed towards the front of the seat. It is why you feel some air blowing through the front. I could actually get a finger in front of the duct and there is a hard plastic insert where the air escapes. you can see it in the picture. It's flat around the edges but shaped like the tube at the seat back. There is only a little padding between the seat and that plastic vent. It seems to hit that padding and then disperse through those top two sections.

The vent that has hot is more towards the back but since there is no duct it just fills the space with warm air. I'm sure some of it escapes the perforated square above the seat pocket on the back of the seat but not enough.

I actually haven't felt much hot air from the lower unit.

 

[Droid_Junky]

I think you are on it in this post the more I think about this.

Here's my latest guess (I've been doing a poor job on my other guesses so take this one with a grain of salt).

The fan is blowing air over the Peltier unit/grid. One side is hot the other cool. The rubber duct vents the cool air to the seat back for the upper unit. The hot air blows out right next to it. That hot air then proceeds to warm up that little rubber duct and when sitting in the seats we compress that duct so basically it isn't flowing much cool air at all and getting warmed up by the hot air blowing right on it.

Now as for the lower, I need to see if there is a little rubber duct down there that does the same for the lower unit on the seat bottom.

I think you guys are onto it and I apologize if I've been scatterbrained trying to figure this out.

The rubber duct is very warm to the touch even after a few minutes. I've got some things to do this morning but I'm up for cutting those two tie wraps that hold the duct. I have some replacements. Curious to see why it is so warm. maybe just wrapping the duct to insulate it from the heat would help?

Mine improved simply by adding the cardboard scoop at the bottom but it could be better. I'm thinking of adding a a CPU fan to force more cold air in their. I have a few laying around.

 

[Free Agent]

The rubber duct is very warm to the touch even after a few minutes. I've got some things to do this morning but I'm up for cutting those two tie wraps that hold the duct. I have some replacements. Curious to see why it is so warm. maybe just wrapping the duct to insulate it from the heat would help?

Mine improved simply by adding the cardboard scoop at the bottom but it could be better. I'm thinking of adding a a CPU fan to force more cold air in their. I have a few laying around.

The rubber duct is pointed towards the front of the seat. It is why you feel some air blowing through the front. I could actually get a finger in front of the duct and there is a hard plastic insert where the air escapes. you can see it in the picture. It's flat around the edges but shaped like the tube at the seat back. There is only a little padding between the seat and that plastic vent. It seems to hit that padding and then disperse through those top two sections.

The vent that has hot is more towards the back but since there is no duct it just fills the space with warm air. I'm sure some of it escapes the perforated square above the seat pocket on the back of the seat but not enough.

I actually haven't felt much hot air from the lower unit.

Its up to you but you may want to hold off cutting those zip ties and undoing the rubber vent. It is shunting the cooled air to the front of the seat where you want it. I think the problem is the hot air is blowing out right next to it heating up the rubber. That is why it feels warm or hot to touch. Frankly the hot side needs its own dedicated shunt or vent to the back side of the seat to keep the two air temperature pathways separate. Its a poor design in my book and only made worse because when we lean back in our seats we are compressing that rubber duct even more cutting off the cool air and pushing it into the path of the warm air.

As for the lower one it seems to be designed a little differently. I don't think there is a rubber duct down there as it is hard to tell. And the duct below the seat seems to be angled differently than the one in the seat back. I think that is why it works much better.

My most current theory now is that IF the upper unit in the seat back had two hard plastic ducts, one to vent the cold to the front side of the seat and one to vent the warm air to the back side of the seat (with a small vent in the seat back) that it would perform MUCH better and more like the bottom unit. Of course they would have people complaining about, "Why do I feel a hard plastic piece in my seat back when I sit?"

Bottom line for me (at this point) Its a poor design for the upper unit and it will never function as well as the bottom one. If it is ever found you can disconnect the upper unit without disabling the lower unit it very well might be worth it as the upper unit succeeds in basically warming the upper seat when it is on and someone is sitting in it. :(

 

[Free Agent]

maybe just wrapping the duct to insulate it from the heat would help?

You might be onto something there. It won't make it perfect, but it could help. Maybe some thin flexible styrofoam material (like the white styrofoam in your picture) wrapped around that rubber duct/boot that is supposed to be venting out cool air.

 

[GT Pony]

The rubber duct is very warm to the touch even after a few minutes.

Sounds like that means the heat rejection from the Peltier unit isn't being separated away very well from the cold side of the unit, which is the rubber duct. If the heat on the hot side was rejected correctly, the rubber hose would get cool, not warm.

 

[GT Pony]

I think the problem is the hot air is blowing out right next to it heating up the rubber. That is why it feels warm or hot to touch. Frankly the hot side needs its own dedicated shunt or vent to the back side of the seat to keep the two air temperature pathways separate. Its a poor design in my book and only made worse because when we lean back in our seats we are compressing that rubber duct even more cutting off the cool air and pushing it into the path of the warm air.

I agree with that.

As for the lower one it seems to be designed a little differently. I don't think there is a rubber duct down there as it is hard to tell. And the duct below the seat seems to be angled differently than the one in the seat back. I think that is why it works much better.

The bottom unit is a whole different configuration ... no duct, the fan just blows directly up into the seat cushion. Can't quite tell how the heat is rejected on the bottom unit by the photos. It could very well be that the white insulator between the hot and cold side of the unit lets a little air bleed through it from the fan to help vent the hot side - ie, a controlled purge.

Bottom line for me (at this point) Its a poor design for the upper unit and it will never function as well as the bottom one. If it is ever found you can disconnect the upper unit without disabling the lower unit it very well might be worth it as the upper unit succeeds in basically warming the upper seat when it is on and someone is sitting in it. :(

Unfortunately, I think that is the case. The unit in the back would probably operate just as good as the one in the bottom cushion if it could efficiently reject the heat it's producing while cooling.

 

[jbailer]

Wow, great information guys, thanks! I have an appointment at the dealership on Wednesday for them to look at mine. I'll let you know what they say. I'll be watching this very closely just in case. Where on the seat back would that vent be coming out? I don't feel any air, warm or cold. Would it be possible to show with arrows in a picture?

 

[Droid_Junky]

Wow, great information guys, thanks! I have an appointment at the dealership on Wednesday for them to look at mine. I'll let you know what they say. I'll be watching this very closely just in case. Where on the seat back would that vent be coming out? I don't feel any air, warm or cold. Would it be possible to show with arrows in a picture?

The duct is roughly the small square. The large square is where I felt air.

 

[Darko66]

That's the exact spot where mine gets the hottest (the inner rectangle). Both in cooled and heated modes. I tested the temps with the heated on and that area is around 130°. That's likely hotter than it would be in colder weather obviously, but seems a little too hot. I don't feel any airflow on the seat back in either mode and all I feel on the backside of the seat is heat radiating from right at the top of the pocket.

I think those of us getting the hot spot obviously have either a different problem or a second problem than those whose just don't cool. Maybe we're missing the foam pad with the air distribution channels or the fan isn't hooked up correctly to it.

There was someone in one of the other threads on the seats that said something about having the wrong pad. Another poster was supposed to be getting their whole back of the seats replaced. Not sure what the end result was, but at least they got some help at the dealer level. I'll have to go back and look through that thread and see if they provided feedback.

 

[Droid_Junky]

the air is very light in the large square even on high. I had to get my hand wet to determine the entire area.

 

[jbailer]

So this is contrary to what I heard before. Someone, including Ford was saying the seat back only cooled at the lumbar region. Thank you very much for this. Will be good info when I go to the dealer. I wonder if anyone can say their seat cools well there?

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