Ventilated seat back fan intake location

[chris1601]

I've done the listerine bottle mod for the seat cushion intake and with the AC on, it gets nice and cold.

Does anyone know where the intake is located for the seat back?

[Inazone]

I've done the listerine bottle mod for the seat cushion intake and with the AC on, it gets nice and cold.
Does anyone know where the intake is located for the seat back?

Ooh do share the mod, this sounds very interesting?

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[chris1601]

I found it on Youtube. Whilst it references an IS250 and the previous gen, it still works great on the gen 3 as well:

 

 

[PCM]

Could that potentially work for any seat I wonder?

Great video and great idea...

[Mincey]

That's worth investigating!

[Inazone]

That's a simple mod assuming we have a fan bolted beneath our seats. I assume that will apply to people who have the ventilated seats, not standard on the executive edition.... [emoji853]

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[ColinBarber]

Even without the mod, putting the climate system to feet allows cooler air to pass under the seat and be drawn up.

 

19 hours ago, chris1601 said:

Does anyone know where the intake is located for the seat back?

Never checked but as the motor is right at the top of the seat it may well get its air from around the headrest area?

 

9 minutes ago, Inazone said:

That's a simple mod assuming we have a fan bolted beneath our seats. I assume that will apply to people who have the ventilated seats, not standard on the executive edition....

Indeed, and unless you have perforated seats it wouldn't really work anyway.

[Mincey]

2 hours ago, Mincey said:

That's worth investigating!

...assuming you have perforated seats already. I just checked and rather unsurprisingly, Lexus weren't kind enough to fit my non-perforated seats with a fan.

[200h]

you can tell if you have the ventilated seats as the seat heater button

has a top and bottom to the switch heated at the top, vented at the bottom

of the switch.

[Inazone]

I wonder how effective the seat ventilation actually is. The heated seats work a treat but trying to get air through the perforations while sitting on the seat must be none existent... Anyone actually got the ventilated seats?

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[chris1601]

The seat cushion is pretty effective by virtue of the air flow being mainly towards the front half where air can escape between your legs. Ducting the foot vent up to the seat cushion and putting the AC on makes it really quite cold indeed but it's by no means essential.

The seat back is different. I feel little effect but it depends on what you're wearing and your build. I'm 6' and 14st and fill the seat fairly well and I find it's not enough ventilation for a long journey. The air gets trapped and after a while it still feels very warm.

I've added a mesh lumbar support thing which puts a little distance between my back and the seat without compromising comfort. I removed the central nobbly part which was just stitched in place. With this mesh support on the seat back, I can feel the warm air escaping from my sides and the ventilation is reasonably effective and good enough. I'd still like to duct cold air from the AC to it if I can figure out roughly where the intake is. 

[Mincey]

The ventilation is quite effective - my wife thought she'd wet herself when I put it on for the first time.

[Texas]

Agreed it is in fact quite noticable and needs to be 'turned down' after a long while, I have read that if used constantly then the fan blades can get covered in crap and reduce efficiency, just like the fans on desk top computers! Yuk.

good, easy mod to try without any actual intervention into the car's operating systems. Well worth a try but it may be a placebo effect if you do it yourself!

paul m.

[Inazone]

Just had a look at my front seats, they are indeed perforated which I never considered. I also checked under the seat and there are a couple of channels which appear to run to the top of the seat ie where I sit... Just wondering how difficult it would be to retro fit the ventilated cooling part? If it's just a fan how hard can it be..... Got plenty of space on the dash to fit a switch.... Anyone retro fitted the ventilated parts?

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[ColinBarber]

1 hour ago, Inazone said:

Just had a look at my front seats, they are indeed perforated which I never considered. I also checked under the seat and there are a couple of channels which appear to run to the top of the seat ie where I sit... Just wondering how difficult it would be to retro fit the ventilated cooling part? If it's just a fan how hard can it be..... Got plenty of space on the dash to fit a switch.... Anyone retro fitted the ventilated parts?

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To retrofit the OEM system would probably be more expensive than selling your vehicle and purchasing one with ventilated seats. New wiring, switch gear, electronics, ducting etc. You may be able to do something non OEM.

e.g. the blower assemblies are around £250 each - you need 4 of those and the seats are probably different so wouldn't just bolt in.

[200h]

my opinion of the IS's heated seats is they are rubbish the seats get warm

and not much hotter than that, the heated seats in the CT are fab you can

cook on those seats and the IS's ventilated seats are poor so if you dont

have this feature your not missing out on much.

[200h]

i have just made the modification from some small bass port ducting

i tried it on the drivers seat first and then turned both seats on

the drivers seat is noticeably better , i will see how good it is tomorrow when

i go to work mid morning.

 

[PCM]

Someone with a 3D printer could knock these out and sell them ...?

[Inazone]

Someone with a 3D printer could knock these out and sell them ...?

Yeah this is what I was thinking. Does the seat back have a fan unit or is it channelled up from under the seat?

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[chris1601]

That diagram was really useful @ColinBarber. I ran some bog roll tests and found that there was no obvious suction for the seat back in the seat back perforations. Even right at the top there was positive pressure outwards when turning the fan on.

I next tried blocking the seat cushion intake and confirmed that there was no effect on the seat back, so it appears that intake doesn't pipe over to the back.

Lastly, I unzipped the left zip on the drivers seat back and saw the seat back ducting. There's actually a lot of room in there and with my hand near the fan itself confirmed that the air intake for the seat back is taken from the seat back void. The void itself when zipped up is fairly tight so I'm thinking perhaps a slight gap introduced at the bottom of the seat back might be enough to suck up some of the cold air from the foot vents. Now to think of something that will do the job, needs to be quite narrow but wide...

[PCM]

I made one out of an Asda Smoothie bottle ( empty! ).

I figured the worst would be it would make little difference.

Kept me out of trouble for 45 minutes...

 

[chris1601]

It's not quite what I had in mind, but I have used an old vacuum cleaner extension hose to duct one of the two footwell outlets under the driver's seat into the seat back void. It's a flexible hose so moves with the seat. There are a few cables to be aware of when pushing the hose through the gap between the seat and seat cover at the back but otherwise it slots in without any drama. 

The car has been sat baking in the sun all afternoon. Seat temperature was about 30c after I got the sun off it with a silver windscreen shade thing. I had the AC on Lo which recirculated, doors and windows closed, still with a lot of residual heat in the car. I had my right hand measuring the temperature of the same point on the seat, my hand resting on the seat to minimise any movement. My left hand holding my phone (excuse the closeups while changing CC mode).

With the climate control on Auto Mode, AC On, S-Flow off and temp set to Lo, all air was coming from the face vents, directed up to the roof. No air hitting the seat directly. I measured a fairly steady 28c and turning on the ventilated seat to 3 it was still steady at 28c.

Then I set the air mode to face + floor, still Lo and still AC On. The temperature of the seat back started dropping.

Set it back to 'auto' mode, still Lo and still AC On. All air is now from the face vents only. The seat back temperature stopped dropping and stayed steady, rising slightly.

Then I set the air mode to face + floor, still Lo and still AC On. The temperature of the seat back started dropping.

So it seems that ducting into the seat back works well. I'll be out for a couple of hours on Saturday so that will be the test.

Video of testing: 

Start with seat fans on full, no air to floor
0:50 - set mode to face + floor
2:15 - back to auto (face only)
3:45 - back to face + floor

 

 

[200h]

well here is my update

i have used the ventillated seats now for 2 days since i

completed the mod and the base of the seat is really cold

and i can now feel air blowing through the seat , my seat position

probably helps as i have my seat as low as possible this means

the fan is as close to the ducting as it can possibly be

[chris1601]

@200h nice 🙂

My seat back mod was quite successful, in combination with the mesh back support. My back was actually cool to the touch after a couple of hours, so much so I turned down the seat fans from 3 which I'd normally use on a warm day to 1. It was actually a little too cold! I think I'll try it next without the mesh back support and see if it still keeps me cool.

[Andrew888]

On 5/27/2020 at 9:33 PM, 200h said:

i have just made the modification from some small bass port ducting

i tried it on the drivers seat first and then turned both seats on

the drivers seat is noticeably better , i will see how good it is tomorrow when

i go to work mid morning.

 

Was this in Auto mode or just footwell mode? I find Auto doesnt have much going on