I'd also like to report ~ My 2016 IS 350 has the same problem. Back seat is boiling with the Ventilation on. The bottom seat is nice.

Anyone try experimenting to just shut off or disconnect the top fan from the switch so the bottom still ventilates while the top stays off?

 

I see it's been mentioned in here but these ventilated seats hold hot air...then the air is pushed out.

I didnt look it up but there is another thread here with pretty recent discussion. It put my mind to rest about the hot seats. The guy took the seat apart and tried a few things but it's just the way it is.

Best fix as I recall was directing the air from the rear vents underneath the seats. The seats draw air in through the bottom and there are 3 fans in the seat not 2.

Since knowing this I start with my air vents directed out front and down in the foot well. And I deal with the hot air contained in the seat coming out for the first 10 min of my drive.

 

I have a 2018 Lexus NX. The ventilated seats work intermittently. I can never predict when they won’t work. Both the driver and passenger seat break concurrently. I have also noticed that when the ventilated feature is broken, the heated feature is also malfunctioning / not working to capacity. Had it to the dealer several times. Only one attempt was made to address the problem. I have brought it in while it is broken, had a tech feel the seats, left the car for a week at a time, picked it up, turned on the ventilated seat and discovered it was still malfunctioning. Never left the lot. Dealer kept car, couldn’t replicate the problem and did nothing. I am currently arguing with service manager who insists they will not fix it if it’s not broken when I drop it off. Each time I brought to dealer it was broken. Today my ventilated seats work. Tomorrow, who knows. Lexus you need to fix this issue. I believe it is the entire system, heating and cooling that is malfunctioning. It happens simultaneously in both passenger and driver seat and when the seats don’t work, the general AC is less effective too. Stand by your car Lexus and find a solution.

 

Anyone tried to redirect the air vent under the seat towards the fans to improve the ventilation?

 

Have you seen my thread on this?

https://www.clublexus.com/forums/is-...-solution.html

the iPhone box pictured in my reply really, truly fixes this issue as far as I can tell. What also helps a bit is just switching the vents from upper only to upper + lower.

 

yes this is exactly what I was talking about.... I did notice today that blasting the AC onto the floor makes a big difference in the performance of the vents in the seats...

 

Just gave this a try. Looks like my box is positioned in the same area. It definitely helped for me, but isn't a true fix. My butt is still much cooler than my lower back.

Kind of a shame, I didn't really realize how lacking our seat ventilation is until I rode in a friend's Mazda 6 last week. Truly put the IS to shame. Oh well, at least the car is still sexy.

 

My lower seat cushion is cooler than the upper too but the seat overall gets so cool that I have to turn the A/C temp higher than I normally would. I no longer have the hot spot and that’s really all I wanted.

 

I was in my friend's B9 A4 as well and it sucks in the air instead of pushing out like 3IS. It works like wonders when we were in Vegas in 110 degrees.

 

I wonder if the fans can be reversed to do the same thing on these seats? I'm sure the seats would probably have to be removed though to do that....

 

I did the mod today and immediately noticed the bottom seat cushion had much colder air. Not so much for the back but on a longer trip I expect it to be better as well. So easy and totally worth it.

However, I wonder if there's a way to keep the A/C in Auto but also direct air flow to the feet? I'm confused why it has to come out of auto if you direct the airflow to the floor.

 

This works very well for the lower portion. Happy with the results...it's like an air conditioned seat cushion.
On the passenger side I simply propped the floor mat up against the bottom of the seat. Similar results but not quite the same.

This also seems to not only provide cool air but increases air flow coming through the seat as well.