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Ventilated seat motors creating hot spots + potential solution
Since it’s been warming up a bit, I’ve been making use of my ventilated seats a bit more. However, I’ve noticed more and more often that I have a hot spot between my shoulder blades. Then I came across this thread in the RC forums with 225 replies and counting:
Once I realized it wasn’t in my head I took a trip to Newport Lexus for my 2019 IS F Sport. I’ve attached a photo to show exactly where the hot spots are.
The shop foreman met with me and sat in my car with me. He very nicely confirmed this is how every Lexus is except the LS as they are only ventilated seats, not air-conditioned (which is something I was aware of prior to visiting)
He actually pointed out a second spot on the seat that warms up, though not as much as the seat back. These are the locations that the two ventilation motors sit.
He offered to to bring a brand new IS F Sport down so we could both sit in it so I accepted that offer. The brand new vehicle never even slightly began to heat up like my car. However, the brand new car was cool inside as it came from a covered parking garage.
I decided to take my car back with me and try the ventilated seats this morning straight out of my garage as I typically only use them when the interior is already hot. I found that after sitting in a garage for 14 hours, the hot spots did not occur where the motors sit within the seat.
At this point, I have to conclude that one of two things are happening: either the closed up motors inside the seats aren’t robust enough to deal with the heat and begin overheating in warm weather or the seats are trapping hot air inside when the outside of the seat already feels cool to touch.
My plan now is to do the “iPhone box mod” where one side of the iPhone box is cut off and cool air from the HVAC vent below the seat is redirected into the lower ventilated seat motor. Hopefully that allows the inside of the seat to cool down quickly when the interior of my car is 100+ degrees.
This helps more than I could have ever imagined! I keep my seat at the lowest position so the box gets wedged between the floor and seat and stays in place. If you tend to keep your seat higher then you may need to tie a rubber band around it to keep it in place.
My seat is so cool now that I almost want to say it’s icy!
So quick question. Does your zone selection need to be a certain setting for air to blow out from under the seats? For example, if you have it set to just have air blow out your dash vents, does air also blow air out from under seat vents? Or do you have to have it set to the blow on feet selection?
So quick question. Does your zone selection need to be a certain setting for air to blow out from under the seats? For example, if you have it set to just have air blow out your dash vents, does air also blow air out from under seat vents? Or do you have to have it set to the blow on feet selection?
You have to choose to have it blowing out the front vents and lower vents for this to work.
I just read through this thread and the cross post RC forum thread as well.
I had no idea this was "a thing" that others had experienced (I was sure I was nuts...)
There is a statement on the RC thread that mentions that this was fixed for model year 2018--but my 2018 IS 350 F-Sport has it as bad as others have described
I wondered if the switches between the seat heaters and ventilation operation had been intermixed somehow.
The seat back gets so hot that I have to shut the vent system off (as many others have said). The seat bottom works pretty well to cool my ****. It's as if the ventilation
is switched on for the seat bottom and the heaters switched on for the seat back.
People are too picky about a "nice to have" feature on an entry level premium sedan. The seat is designed to move existing air within the cabin and through the seats. It's not really going to do much beyond that. Also the efficacy of the system not only depends on the cabin temp, but the exact shape/size/pressure/areas of pressure the body that sits on it. Obviously depending on where your body mass rests on the seat, and what you're wearing, your results will vary as to where air is able to flow through or around your clothes, giving (or not giving) the perception of "cool." Just depends how you're shaped and what parts of the seats you're body is pressed on and how hard it's pressed.
In short, there is way too many variables involved to ensure every single driver is cooled the exact same way. It's just one of those "ahh this is neat" features and not something to completely rely on keeping you perfectly cool in every situation for every driver.
My ventilated seats on my 200t were grand. Didn't really notice any hot spots. though my body may not sit on the seat the exact same way everyone elses does.
Vinyl is going to be hot in general. Having holes helps. Having holes that air moves through helps. But still--it's vinyl. You are sacrificing ultimate comfort to *not* have cloth seats.
People are too picky about a "nice to have" feature on an entry level premium sedan. The seat is designed to move existing air within the cabin and through the seats. It's not really going to do much beyond that. Also the efficacy of the system not only depends on the cabin temp, but the exact shape/size/pressure/areas of pressure the body that sits on it. Obviously depending on where your body mass rests on the seat, and what you're wearing, your results will vary as to where air is able to flow through or around your clothes, giving (or not giving) the perception of "cool." Just depends how you're shaped and what parts of the seats you're body is pressed on and how hard it's pressed.
In short, there is way too many variables involved to ensure every single driver is cooled the exact same way. It's just one of those "ahh this is neat" features and not something to completely rely on keeping you perfectly cool in every situation for every driver.
My ventilated seats on my 200t were grand. Didn't really notice any hot spots. though my body may not sit on the seat the exact same way everyone elses does.
Vinyl is going to be hot in general. Having holes helps. Having holes that air moves through helps. But still--it's vinyl. You are sacrificing ultimate comfort to *not* have cloth seats.
I disagree. It is simply a bad design that doesn't work the best. I have a Ford Super Duty Truck (Yes FORD!) with ventilated seats as well. No matter hot it got inside, how hot the seats are, or what I am wearing, those seats get cold in about 2 minutes--every time--even through thick Levi's.
I guess to me, I don't see how Ford can get it right, but Lexus has trouble with it.
I have been using my iPhone box under the seat for several days now and can confirm the hot spot has been minimized to the point that I’d say it’s just about gone. I don’t notice it on my back at all but I think I can feel it with my hand on a hot day.
My ventilated seats work so well that I've actually been turning the temperature of the HVAC up because my legs and back get too cold.
People are too picky about a "nice to have" feature on an entry level premium sedan. The seat is designed to move existing air within the cabin and through the seats. It's not really going to do much beyond that. Also the efficacy of the system not only depends on the cabin temp, but the exact shape/size/pressure/areas of pressure the body that sits on it. Obviously depending on where your body mass rests on the seat, and what you're wearing, your results will vary as to where air is able to flow through or around your clothes, giving (or not giving) the perception of "cool." Just depends how you're shaped and what parts of the seats you're body is pressed on and how hard it's pressed.
In short, there is way too many variables involved to ensure every single driver is cooled the exact same way. It's just one of those "ahh this is neat" features and not something to completely rely on keeping you perfectly cool in every situation for every driver.
My ventilated seats on my 200t were grand. Didn't really notice any hot spots. though my body may not sit on the seat the exact same way everyone elses does.
Vinyl is going to be hot in general. Having holes helps. Having holes that air moves through helps. But still--it's vinyl. You are sacrificing ultimate comfort to *not* have cloth seats.
Completely disagree with this statement when Lexus is charging you thousands to add luxury packages for these options to add to your vehicles
For the original thread poster, how does this scientifically help keep the air cooler? Do you mind explaining? Will try soon
I just read through this thread and the cross post RC forum thread as well.
I had no idea this was "a thing" that others had experienced (I was sure I was nuts...)
There is a statement on the RC thread that mentions that this was fixed for model year 2018--but my 2018 IS 350 F-Sport has it as bad as others have described
I wondered if the switches between the seat heaters and ventilation operation had been intermixed somehow.
The seat back gets so hot that I have to shut the vent system off (as many others have said). The seat bottom works pretty well to cool my ****. It's as if the ventilation
is switched on for the seat bottom and the heaters switched on for the seat back.
Just adding my experience to the list.
Some RC owners have pulled fuses for heated seats and had no success. Additionally, the technician was able to show me the hot spots are exactly where the ventilation motors are so I don’t believe the seat heaters are being accidentally engaged.
This helps more than I could have ever imagined! I keep my seat at the lowest position so the box gets wedged between the floor and seat and stays in place. If you tend to keep your seat higher then you may need to tie a rubber band around it to keep it in place.
My seat is so cool now that I almost want to say it’s icy!
Completely disagree with this statement when Lexus is charging you thousands to add luxury packages for these options to add to your vehicles
For the original thread poster, how does this scientifically help keep the air cooler? Do you mind explaining? Will try soon
Originally Posted by Neat
Is there a tutorial anywhere?
Literally break down one side of an iPhone (or similar) box top. Stick that broken down side under the vent below the seat so the three intact sides force air upwards. The vent is designed to provide A/C for the footwell area of the rear passengers. Personally, I keep my seat as low as possible so I just lowered it back down and the intake on the bottom of the seat naturally sits right on top of the box and it does not slide around.
Amazing.. I came on here as I was feeling the same heat in our nx 200t. My wife thought I was imagining it. She finally agreed. The iPhone box trick actually works.. but it shouldn’t come to that. I’m taking it in to Lexus and telling them to come up with a cure. Doubt if it will happen. Thanks for the sanity check folks.
07-27-19, 09:51 AM
Ventilated seat motors creating hot spots + potential solution
