Radiant Heat From Vents??

[BlownPony306]

Anyone else experience heat coming out of the vents when the hvac system is completely off? I generally drive around with the windows down unless its about 100 out. And unless I have the ac on I get a horrible heat coming out of the vents. It's enough that makes you sweat.

 

[95PGTech]

Lots of JDM Saleen supercharged cars have this problem - the current theory is that the motors are generating so much horsepower that they're trying to dissipate some of it as heat since holding it in would probably mean explosion - the engine bay fills with all this horsepower and even then it's not enough. So it has nowhere to go but find openings, one of which is the heating system into the cabin. Eventually the cabin fills up and its forced out small openings into the atmopshere. We have so many JDM Saleen supercharged vehicles running around these days, the atmosphere can't even hold all that horsepower in anymore and we're punching holes in the ozone layer. The EPA is all over my phones every day trying to get us to detune some of these cars!!!




On a serious note, does it do it with the indicator in the max a/c position but without the air conditioning actually on? as in, closing the outside air door completely? my car at speed in any setting where that outside air door is partially open the cabin will start to have real small amounts of ambient hot air coming out.

 

[cekim]

On a serious note, does it do it with the indicator in the max a/c position but without the air conditioning actually on? as in, closing the outside air door completely? my car at speed in any setting where that outside air door is partially open the cabin will start to have real small amounts of ambient hot air coming out.

Also, I have noticed, I get some warm air with everything off if the temp/mixer knob is not all the way to the cold side.

 

[travelers]

Mine does it also. Its another great feature that Ford engeneered into our cars

 

[GRAYPNY]

Yeah, it's very annoying.

 

[JimmyD]

I get it too, not alot, but you can feel it coming out of the vents slightly. Also, it seems I get more heat from the trans tunnel area, over 70 degrees out, you gotta crack windows or put the a/c on to take the edge off.

 

[05stroker]

I get it too, not alot, but you can feel it coming out of the vents slightly. Also, it seems I get more heat from the trans tunnel area, over 70 degrees out, you gotta crack windows or put the a/c on to take the edge off.

Me too! I saw a thead on another forum also about excessive heat on leg while driving.

 

[BlownPony306]

Lots of JDM Saleen supercharged cars have this problem - the current theory is that the motors are generating so much horsepower that they're trying to dissipate some of it as heat since holding it in would probably mean explosion - the engine bay fills with all this horsepower and even then it's not enough. So it has nowhere to go but find openings, one of which is the heating system into the cabin. Eventually the cabin fills up and its forced out small openings into the atmopshere. We have so many JDM Saleen supercharged vehicles running around these days, the atmosphere can't even hold all that horsepower in anymore and we're punching holes in the ozone layer. The EPA is all over my phones every day trying to get us to detune some of these cars!!!

Well damn!! I must have some special factory ringer then! lol!!

On a serious note, does it do it with the indicator in the max a/c position but without the air conditioning actually on? as in, closing the outside air door completely? my car at speed in any setting where that outside air door is partially open the cabin will start to have real small amounts of ambient hot air coming out.

I don't think it does. I'll try it on the way home tonight. I generally cruise around with the ac/heat in the straight up off position. I just hate robbing power to do nothing. But since I am making so much power maybe I have some to spare!! lol

 

[Bingo]

I also experience this. The whole dash gets warm, and I'm pretty sure it's not from the ambient air, because it gets warm in the winter, too. And yes, the trans tunnel and even some of the plastic gets warm.

I don't mind too much - I rarely put the a/c on, and with the windows down in the summer, it just mixes in with all the other hot air.

 

[BlownPony306]

It almost reminds me of how my old fox would get warm because of the built motor, long tube headers and auto trans. But this car shouldn't do that. I am taking in Monday to address the speaker/window button rattle tsb and the exhaust rattle. I am having them look at it then for the heat too. Will see what they say.

 

[ZmanM3]

I just turn on the AC myself.

 

[BlownPony306]

Well they said it is normal. Has to do with the blend doors and how they operate when the HVAC control is in the off position. Allows hot air thru. They said, "It may not be a very good design but it's the design."

 

[cekim]

Well they said it is normal. Has to do with the blend doors and how they operate when the HVAC control is in the off position. Allows hot air thru. They said, "It may not be a very good design but it's the design."

As I mentioned, I only every noticed this when I had the mixer somewhere other than max cold and everything was off (i.e. the heater core is still hot and if the blend door is not all the way closed - mixer in full cold - then you get heat coming out).

Do, you still get heat even in that position?

 

[06gt4rad]

I keep the vents closed but i do get heat from the floor board and it is really bad in hot weather. I am pretty certain it is the cats radiating heat through the floor board.

 

[05stroker]

I keep the vents closed but i do get heat from the floor board and it is really bad in hot weather. I am pretty certain it is the cats radiating heat through the floor board.

Its not the cats cause I dont heve them and I get the leg heater as well I thought about pulling the seats and carpet and installing some kind of light weight heat barrier.

 

[06gt4rad]

http://www.secondskinaudio.com/products/Acoustic-Car-Audio-Noise-Reduction.php

 

[BlownPony306]

As I mentioned, I only every noticed this when I had the mixer somewhere other than max cold and everything was off (i.e. the heater core is still hot and if the blend door is not all the way closed - mixer in full cold - then you get heat coming out).

Do, you still get heat even in that position?

Yeah it doesn't matter what position the mix is in. If the control is in the off position heat blows in. Here is exactly what they put on my service sheet.

"When hvac systen is shut off, hvac doors remain in default open setting to allow condensation moisture to evaporate. This also allows outside air to flow in to the cabin, especially when vehicle is moving."

So as far as they are concerned it's a normal condition.

 

[06gt4rad]

So their saying it defaults to the vent position when off. Hmm sounds fishy

 

[05stroker]

After driving 260 mi round trip to Dallas yesterday with no AC I had a lot of time to feel around in my hot ass car while driving in 95 deg heat . Here are acouple of things I noticed alot of the heat seems to be coming from the floor pan but I think even more homes from the heated itself not from the vents but from what I am assuming is the heater core housing . I am thinking of trying to install some sort of elec valve inline on the heated hose in the engine bay so that when the heater is not in use there is no hot water in the core to heat up the cabin. If anyone has heard of such a valve I would love to hear about it. I think I will also install a radiant barrier under the carpet on both sides of the car.

 

[Dread53]

A couple of my musings.

First, if you think about installing a valve to shut off the coolant flow make sure you put in a jumper line to keep the coolant from deadheading. The Taurus's did that some years back and had a recall to flush the systems for corrosion due to aeration.

Second, I've removed the rubber strip at the rear of the hood to keep hood flex down, which allows underhood air directly into the interior vent system. Remember, the intake is right there at the base of the windshield. This makes it very noticable when sitting at a light or at very low speeds.

This doesn't mean it's any less crappy a design, just some explanation.