sun > hot interiors... electric tint?

[miekedmr]

Cars tend to act like greenhouses during the summer, to the point where I can't hold on to the steering wheel. Sometimes I have to park out in the sun someplace where I can't leave the windows open (and give people access to the inside.) It seems like a big waste of energy to counteract that heat buildup using AC... and even then you have to wait for it to cool off.
There's those foily windshield covers, but they're ugly, bulky and a PITA. I was trying to come up with a more creative way of dealing with it, and wondering if anyone has come across anything for like this for sale.
Electric tint for the windshield/windows would work very well I think. I could have a switch to tint the windows (probobly wired so no one can tint the windshield while the car's running,) that turns off if the battery drops below a certain voltage (to prevent draining it.) LCD's in calculators draw a very small current I believe, so I can't see it being very taxing. It wouldn't be too hard to hook a small 12v solar panel into the electrical system either...
I have no idea where I could get electrically tintable stuff to apply to the windows, however.

My much less elegant, lamer, but more realistic idea was to hook up some 12v 120mm computer fans to the same kind of circuit, to draw cold air in from under the car and force hot air out the top, through cracked windows or sun roof. Vinyl would still get hot under direct sun but it would be an improvement, much like leaving the windows down.

Thoughts, besides me overcomplicating things?

 

[born2drv]

LED TINT???? I've never heard of such a thing....

All you can really do is use real tint. I have 15 all the way around and it helps a lot.

I also plan to put a very dark strip of tint on the top of the windshield after I replace the glass.

 

[CTsupra]

^ that's what i did to my old 89'. 50% all around, including the windshield strip. helped a lot.

miekedmr: sounds like a good idea if you can get it to work! ...something like those rx glasses/sunglasses that you can buy that automatically darken, or tint themselves in the sunlight, but on a swich.

 

[miekedmr]

LCD tint.. LED's produce light.
I have read of newer cars having sunroofs that are tinted, and when you flick a switch it applies voltage to the glass and it turns clear.
For a windshield you would want the opposite, clear without voltage and dark with voltage, otherwise you would run the risk of the windshield turning dark while driving if something failed electrically.

 

[Shytheed Dumas]

I like your idea a lot. Since they have it for sunroofs, I can't see why it couldn't be applied to the rest of the car. I don't fully understand LCD's, but the question I have is whether the redundant safety feature of clear w/o voltage would work? Can you just reverse them like that? I think it would have to be built that way or it would never be approved in case of electrical failure, just like you said.

I've had a similar idea for years for a much better windsheild defrost. I always wondered if a clear conductive material existed that could be sandwiched between the windshield layers to make a defroster similar to rear windows without the lines. That way you could have the speed and effectiveness of rear window defrosters instead of relying on the car to heat up. Wish somebody would make that work and get it on the market...

 

[HIDPLANET]

Another cheap solution without having dark tint on the front widndshield or other windows is to use Zero-Tint. Its UV film just like most good brand tint, but is crystal clear. It blocks out harmful UV rays and also keeps a good amount of heat out even during direct sunlight. Its not gonna block heat like limo tint, but it help a lot if you park in direct sun all day.

 

[SupraMario]

For a windshield you would want the opposite, clear without voltage and dark with voltage, otherwise you would run the risk of the windshield turning dark while driving if something failed electrically.

I was thinkin that too.
In fact, I prolly wouldnt even mess with the windshield, just buy a cover and use it.

 

[SupraDerk]

The way I understand the electric tint technology to work is that there is a polymer film that reacts to current flowing through it. There's the film on top of a conductive glass...and whenever current flows through the sheet the polymer reacts to it and darkens. I think if you can find the film and the conductive glass and someone to cut it to the specs you need...you might be able to get it to work.

The LCD thing on the other hand I'm not too sure of what you mean by that. I don't think any kind of LCD blocks UV light...I haven't heard of any kind of negative logic (turn on when recieving no signal...in this case I would imagine a second power line from a sensor or a switch) LCD out there.

-Derek

 

[CPT Furious]

I also just saw some new gadget on TV that attaches to your window and using solar cells, powers a small fan to circulate air through the interior and out the crack in the other window.

Can't remember how much, but if you did this with a cracked sunroof, it would probably work pretty good, plus it doesn't use the car's power supply.

 

[miekedmr]

The LCD thing on the other hand I'm not too sure of what you mean by that.

I mean like a display on a calculator. its completely transparent except when voltage is applied, then sections turn black.. that's liquid crystal I believe, it's just not backlit and much less complex than say a LCD monitor.

 

[miekedmr]

Another cheap solution without having dark tint on the front widndshield or other windows is to use Zero-Tint. Its UV film just like most good brand tint, but is crystal clear.

Cool, I wasn't aware of that..

 

[johnathan1]

Those little solar powered fans have been around for years...I remember my grandma having one in her car, and that was like 13 years ago...

 

[miekedmr]

Those little solar powered fans have been around for years...I remember my grandma having one in her car, and that was like 13 years ago...

I thought up the fax machine too when I was maybe 8 years old, later to discover there was already such a thing..

 

[SupraDerk]

I mean like a display on a calculator. its completely transparent except when voltage is applied, then sections turn black.. that's liquid crystal I believe, it's just not backlit and much less complex than say a LCD monitor.

LCD's work by blocking visible light...it's like messing with two polarizers. If you align them...light passes through, if you start to turn one sheet, then eventually all light is blocked out. You still have UV and IR coming into the car and heating it.

-Derek

 

[Clip]

is there an electric tint readily available? iirc there was something in a new ferrari or lambo that used this tech, but i think it was built into the glass. it had liquid crystal in the glass and when a current ran through it, the crystals would align themselves with the current, decreasing the transmission of light. when the current stopped, they would go back to their normal alignment and let all light through.

i hadnt known there was a product that could be applied like tint.

how about some dry ice or somethin?

 

[Turbo. Targa. Life.]

Polarization was exactly what I was thinking of. Actually I thought it up 3 years ago and was smart enough to have my dad's lawyer hook me up with copyright info

Unfortunately I'm not sure how well it'd work, because heat still gets through, just not light.

 

[Clip]

cheers, TTL, congrats on the copyrights. but if you decrease light, will you decrease heat too?

 

[thesandymancan]

i'm almos positive heat depend on the uv rays. correct me if i'm wrong.

its a great idea.

iknow they have bathroom shower doors that go from clear to cloudy when an electrical current is applied. that tech. with tint would be awsome!

 

[CRE]

UV is creates the majority of the radiant heat, but not all of it.

In regards to the LCD tinting, one of the biggest downfalls is its sensitivity to temperature. Get it too cold and it'll go solid black on ya. I've heard a lot of complaints about that in regards to its employment in commercial and residential windows. I don't think the polarization has any effect on that issue either.

The stuff I've installed required two parallel rails for the power, otherwise you would get inconsistent levels of tint. As such that stuff may not work for automotive use.

 

[NgoFcukinWay]

reminds me of K.I.T. from Knightrider....