Active Ventilated Seats- Opinions Wanted

[X5FX]

unless the cabin air magically cools itself as it passes thru the leather, this is coming from the AC.
The air is very cold, so not sure how the cabin air could feel like this.

regardless of where the air is coming from, it is very cold air...I have never had any issues with it not being cold. I live in Louisiana and it is very hot in the summer. When I get in the car the first thing I turn on is the ventealted seats and the air is cold...and the cabin temp is over 100.

[pvandam]

This is a very interesting thread.
Today my car was in for a check up of the Ventilated seats.
My complaint was that they were not cool enough.
When the outside air temp was colder (60's, some weeks ago) I would really feel quite quickly the cooling of the seats when you turn in on.
Now, when the temperture is moving towards the 80's, the seats seem to have more prolems cooling and that is why I brought the car in, thinking something was wrong.

My dealer confirmed that the AC is not involved in this system at all, and that (as also confirmed by a few on this board) the air is coming directly from the area below the seats.

This is a bit disappointing of course as this does explain why, when it get's warmer outside, the system is less effective as the air is warmer inside.
But isn't that why we bought this feature??

Very interesting what X5FX is saying as this seems to indicate that AC is somehow involved.

When the temperature goes above the 80, I simply have a hard time noticing the ventilation of the seats. And this seems to confirm that it is not controlled through the AC.

Maybe in markets where there is a higher average temperature, this does work through the AC? Would that be possible? Sounds strange, but might be the only explaination why people describe 2 different behaviors in this thread. One saying that the seats are really cold (also in warm air conditions) and the other, that it's not so noticable.

Curious about other thouhts.

[bmwestcoast]

I bought them for a few reasons:

1) I don't like a sweaty backside after spending a few hrs in hot car with leather seats...not like it ever really gets hot in Seattle though. Curious to know if it's cooled by electric fans or the actual A/C..
2) "Active" seemed neat for those 14 hr road trips I do on occasion up to Canada...maybe it will help from keeping my legs, back and a$$ from falling asleep
3) Because 14-way power seats are just not enough so I needed 20-way (joking) :p

[juicer]

So, if its cabin air and you fart - does that just make things worse with ventilated seats
just a thought?

[X5FX]

All I can say is when I get inside my car and the cabin is 100 degrees...the air blowing thru my seat is absolutley cold...if this was cabin air that would not make any sense.

[Viperfreak2]

How about: there's an A/C vent pointed under the seats, and the fan circulates this cooled air up into the seat?

[X5FX]

bottom line is it works extremly well in hot environs...so who really cares exatly how.

[bmwestcoast]

I care, I like to know how things work/break. According to the dealer I just spoke with yesterday it uses fans, not AC. The fans simply blow air up through the perforated leather. I would assume, that if you have your lower AC vents on, it would also then pick up some of that cooled air and pass it through the seat as well. Not sure if the fans are encased within the seat itself but to X5FX's point, moving air through it regardless if it's cooled or not, will reduce the amount of trapped heat.

[Penguin]

It also can depend on the humidy and sweat factor. If you are in a hot, but very dry, climate like Phoenix in the summer, 100 degree air at 4% humidity can feel very cold if your skin or clothes are sweaty... just ask anyone who has gotten out of a swimming pool in Phoenix when it is 110 degrees with a breeze. If your shirt is damp and the air is very dry, even warm air coming out of the seat will feel cold.

[xnsf]

There's a company called Amerigon which manufacture MicroThermalModules which takes use of thermoelectricity. Looks somewhat like a turbine. Within it, there's a heat exchanger and a Peltier circuit (the main thermoelectric doing). The cooled or heated air enters the seat, and the waste air exits the seat.

In the seat itself, there are channels which are molded in foam. Then a layer of scrim material and a distribution layer, and finally you have the perforated leather.

So no, the seats aren't linked to the car's ac.