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Car Colors - Is White Cooler in the Desert?

I live in the desert and have always wanted a
white car. A dealer (with a green car to sell)
recently told me that a study was done - and there
is no difference in how hot a car gets based on
color! I have subjective evidence to the contrary
- put your hand on a white car in summer and its
cooler than a black car.

So - whats that truth?
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Comments

  • Most of the interior heat is absorbed through the glass, but some does creep in through the painted surfaces. I heard a talk by a PPG Paint guy a few years ago, and they were working on an "eggplant" paint: one which looks dark in the visible spectrum, but which blocks heat. (Eggplants are cool to the touch, no matter how intense the sunlight.)

    As for the answer to your question, the white car will be less hot, but certainly not cool, in the desert sun.
  • rfellmanrfellman Posts: 109
    I lived in Florida for years. White is cooler. Open any high school physics book and you should find references to empirical evidence that the color white absorbs less solar energy than blue, green or black. Try successively wearing two identical cotton t-shirts, one white and one black in direct sun light for 30 minutes each. You can either weigh the perspiration absorbed or just subjectively measure your relative comfort. Further, White paint is less likley to fade from long term exposure to direct sun light than are darker colors. Walk barefoot under a midday sun in August and tell me the light colored side walk is not cooler than blacktop in the street.
  • Mr_ShiftrightMr_Shiftright CaliforniaPosts: 45,116
    Just try and sell a black car in summer in Arizona!

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  • I agree that the exterior colour of a car makes somewhat of a difference, but I think that the number of windows and the interior colour are even more important. Dark colours reflect less of the sunlight then pale colours so a dark interior will heat up the interior like a boiler room.
    I lived in Kuwait (it's damn hot there) for a couple of years and drove a old white Dodge Aspen wagon with a dark blue interior. It also had vinyl covered seats. The thing was deadly if left in the sun (usually didn't have a choice, not many trees in Kuwait). I had to sit on three layers of thick beach towels and use leather driving gloves just ot hold the steering wheel. I also drove a dark blue Firebird. That car had a light grey and white interior and was much cooler. I still had to sit on beach towels and drive with gloves, but it was not as bad.
    I concluded that the Aspen was worse because it was a wagon and had a dark interior. All those windows did little to prevent the sun from cooking the inside of the car. The Firebird was the opposite of the aquarium-like Aspen: smaller window surface and lighter coloured interior. It did not heat up nearly as much as the wagon.
    Now I live in Canada (it's damn cold here in the winter) and I would not consider buying a white or light coloured car. The reason is that light coloured cars rust much more quickly then dark cars. On a dark car, the sun will heat the metal and dry the moisture (even when it's colder then 32F), helping to reduce the effects of corrosion. With a white car, the metal would not get hot enough to evaporate the moisture, leading to faster corrosion.
    A solution to keeping some of the heat out of the car is to use window tint. Some after-market window tints have a film that helps to reflect some of the sun's heat. I have also seen these solar powered fans that you stick in the window of your car (roll up the window on it). They are about two inched high. The fan circulates the air in the car, keeping it cooler.
  • rfellmanrfellman Posts: 109
    Gees, I guess unless someone has owned a saab and lived on a volcanic vent, we have the definitive word on hotter than any Saab should be.
  • I've lived in Florida for the last 5 years, and I can tell you that white cars are definitely cooler in the sun - at least on the outside! A simple trip into any sunny parking lot will prove it. Just find a white car parked next to any other color and put one hand on the top of each. What a difference! Even lighter-colored cars such as biege and sky blue are *much* hotter than white. Although there is undoubatbly some insulation between these exterior surfaces and the car's interior, I'm sure some of the heat gets through.
    However, I agree with that the windows are the primary route through which the sun's heat enters the car. Sunlight that strikes the car's exterior must penetrate by conduction through the frame and any insulation inside, and most of it will dispserse into the air from the heated surface instead. But any light going through the windows is basically 100% transferred to the car's interior. (The only bit that escapes is the light you see when looking into the car from the outside!) From a heat-absorbing point of view, all of the car's transparent sufaces are "black". I'd even be somewhat surprised if a light-colored interior mitigated this effect much. While it's certainly true that a light seat would reflect more heat away from itself to other parts of the car's interior, I doubt if much of that reflected heat goes back out through the windows. Maybe we could get a real physicist to enlighten us on this. :-)
    My question is: How much does window tint help with keeping cars cooler in the sun? It seems that darkening the windows would block some sun from going directly to the car's interior, but at the cost of absorbing the heat into the glass itself. The heat could then be conducted to the air inside the car at the hot windshield's interior surface. You only really get rid of the heat if you *reflect* it away. Can somebody who's had their windows tinted recently comment on this? If I go to have my windows tinted after-market, what do I ask for to get the reflective stuff?
  • Try this link. http://www.shadeofday.com/ and look under auto tinting. The company mentions that the window tint film will block(??) 55-70% of the sun's heat. I have had the windows on my black 98 Corolla tinted with a similar product and I did notice a difference, although 55-70% seems exagerated.
  • I've had a black car for a while, and being a Ford, it's rusting despite its supposed advantage per ylockhead above. The other problem with dark colors is whatever drops on it (sap, birdies) bakes on instantly in the sun. Despite the obvious evidence to the contrary as set out in these posts, I can't help but think white will be much cooler inside.
  • cticctic Posts: 291
    Black is very hot. I drove a charcoal colored car in CA and it was much hotter than a yellow car I subsequently drove. I also agree with #3's white vs black tee shirt comment. What I don't understand is why Bedouins wear black cloaks in the desert. Can ylockhead answer that?
  • 300z300z Posts: 7
    blaikm,
    You state that a tinted window will heat up by absorbing solar radiation and then transfer this heat to the car's interior air by conduction. Well, actually most of the heat given off by conduction will be given off to the outside air(via the exterior surface of the window). And since the coating is on the exterior, most of the heat will go to the outside, since glass is not a very good conduter of heat.
  • #8
    I agree with the fact that tree sap and bird crap will 'bake' more on a dark car, but a good wax should help in protecting and making it easier to clean off

    #9
    Don't know why bedouins wear black (or other dark colors), but they usually didn't walk around in the sun during the hottest part of the day. Personally, I prefer a white t-shirt.

    I think I'll get one of those shades for the windshield for next summer. I'll post the results of my experiment.
  • bchaubchau Posts: 8
    Is the "purpose" of this enquiry, can I buy a "bad" black car in Arizona?
  • I am planning to buy a car that I've always wanted - not real sure just yet what that is - but I do know some of its attributes.

    I have always felt that I want a white car (living, as I do, in Arizona). I believe it will be cooler.

    A dealer - who happened to have a dark green demo accord EX V6 coupe - with all the goodies so that the sticker price as $29K - said that there had been a study done - and that white cars are actually no cooler than any other car in the desert. I mentioned this to another dealer that was bugging me over the phone - and he said the same thing.

    So - true or a conspiracy to not sell me a white car!?

    There is obviously some physics involved here. If the hood is hotter - does that make the inside of the car hotter? Does it wear only rubber components quicker if the engine comparment is hotter?
  • 300z,
    Having never had tinted windows, I wasn't aware that the tinting film was on the outside of the window. In fact, that comes as kind of a surprise to me. Wouldn't that make the film deteriorate much more quickly (being constantly hit by wind, rain, assorted debris, acorns, etc)?

    Another Q: For years I have used Rain-X on my windows (greatly improves rainy-weather visibility, especially at night). Can you use Rain-X on an externally-applied tinting film?
  • Externally tinted windows - not in this part of the country. Here in AZ, windows are tinted - if they are tinted - on the inside. At least that's how they are tinted on my '95 Honda - and on all my budies vehicles also.
  • As far as I know, window tint is applied to the interior of the window. Up here in Canada, scrapping ice off the windows of a car would destroy a tint film if applied on the exterior.
  • We live in SE Texas and it seems it's always hot here. The summers are true scorchers! Window tint is a must to survive. It really does help. We tint all our vehicles, usually aftermarket. We pick a tint that "matches" with each vehicle, but also go with a mid - high grade "sunscreen".
    Oh, and make sure they guarantee their work. Tints vary in price, UV blockage, and guarantees. Our newest vehicle has a lifetime guarantee on the tint. If you want the reflective stuff, they carry that, but not the mirror tint, as that's illegal to have.
    Again, tint does make a difference in the interior heat of your car.
    And, FWIW, all our cars are tinted on the inside of the window. :-)
  • sebarge,
    When you say "sunscreen", are you referring to a characteristic of a tinting film or one of those auto sunshades you stick up in your windows when you leave the car? I have one of those now (the cheap folding cardboard variety) and it definitely helps keep the car cooler when I have to leave it in the sun. I understand there are nicer "space age" versions of these sunshades that reflect more heat than the cardboard. Anyone had any experience with them?

    The thing that worries me most about getting my windows tinted is fear of getting a bad job. I see many cars around town whose tinting film obviously wasn't sealed properly when it was applied, causing the film to "bubble up" away from the window. Looks terrible. Even the tint on the Lexus owned by my girlfriend's mother has problems: one of the rear side windows was done so badly that it looks like you're trying to see out through stained glass. (And that tinting was done at the Lexus dealership!) Are there any tinting chains that anyone could recommend where I can avoid such sloppy jobs? Roughly what's a resonable price for a quality tinting job?

    One final issue: How much does window tint impair your ability to see well at night?
  • I've tinted my windows and share in the general chorous that it makes a big difference here in AZ. Just don't do it yourself. I don't know this for sure - but I'm of the general opinion that most of the crappy, bubbly stuff is do it yourselfer's.

    No difference in night driving.
  • In referring to "sunscreen", I meant the window tint's blockage, just couldn't think of the correct word to use.
    Nope, no difference in night driving, unless you get that limosine tint, which is extremely dark.
    Ask around about the shop you choose; they need to be established, and to guarantee their work.
  • Definitively don't try to do the window tint on your own. I have tried on my old car and failed miserably. I bought the 'good' stuff at the auto parts store (Canadian Tire) and it was still crap. It bubbled after a few days even thought I followed the instructions carefully.
    As for night time driving I find that it makes a difference when checking the blind spots (I have a fairly dark tint on the rear side and rear windshield). It definitely makes it harder to see cars at night!
  • gobiegobie Posts: 1
    The bedouines wear black so they sweat more. This way they cool themselves more efficiently and it counter acts the effects of the heat.
    I have also heard from other sources that the exterior color does not effect interior temperature of the car due to construction. The only effect is from the sun entering the windows. The sunlight passes through the windows and is absorbed by the interior colors. If the interior is a lighter color some of it will be reflected back out but not all of it. That is why the cardboard blockers work. Most are light in color to reflect the light and the light does not get reflected into the lower areas of the car.
  • My experience has been in the Palm Springs Area in summer, and it is that the lighter vehical is cooler (this is a relative term for sure). A lighter interior is also cooler, and those reflective shiney things in the windshield are VERY effetive. It ain't cool, but can be 10 degrees different inside. (Don't let anyone tell you that there is no difference after you reach 110.) If you are inb an area where you can do this, crack a window to let the superheated interior air out.
  • I have tinted all 6 cars I've owned in Houston over the years, and never had "bubbling" problems. I've spent a little more having it done at the dealer when the cars were new, which the dealer warrants. I think some problems occur if you use amonia-based cleaners afterwards. This screws up the adhesive properties.

    I find that tinting reduces the heat that reaches the interior, and keeps things from fading. I recommend as heavy a tint as is legally permitted.
  • ruking1ruking1 Posts: 14,916
    White is cooler by app 10- 20 degrees cooler than say ones that fall the middle of the visible spectrum to the darker end.
    (the easiest way to explain it is not so easy, but can be viewed in terms of Ansel Adams Zone system)
    The tinting incorporates metallic particles which in order of importance to me is filtering out UV light, and thus allows less heat in that hits inside masses which store and give off heat by conduction.
    In practical terms, the air conditioner is in fan 2 speed and in darker vehicles in fan 3 and 4 speeds to maintain the same perceived ride comfort.
  • slayv1slayv1 Posts: 1
    The overall verdict is definitely correct, lighter is cooler. Having a minor in physics, I'm only a minor authority. =) Here's the deal:

    White reflects light. Dark colors absorb light, then radiate the solar energy as heat. In the interior of a car, here's the results. A lot of the light that's reflected off of the light colors is reflected right back out of the windows. The dark interior absorbs that light and warms the stagnant air via conduction. Thus making the darker interior color a hotter car.

    How does tinting come into play? Well, it partially reflects, partially absorbs that light. Granted, there's quite a bit of light that still makes it through (otherwise, you couldn't see *grin*), but a significant portion of that solar energy is filtered out. So, what's the difference between the tint absorbing the energy and the interior? Glad you asked. First, the surface area of the tint is smaller, so there's simply less area of the car giving off heat to the interior of the car. Secondly, the tint radiates heat in both directions, inside and outside of the car. If that were the only thing in play, your car would get hot at half the rate. As it is, it helps significantly.

    So, how can people say that there's no difference between the tempatures of light and dark cars. The cheap answer is, there is no difference in how hot either car gets because they'll both peak at the same temp (although I've never experienced a temp. peak). The difference lies in how fast they'll reach that temp. Again, in most modern cars, you're not going to feel too much of a difference between a dark and light car if the interior is the same color due to the engineering / insulation of the cars. However, get two cars of differing interior colors, and I'd prefer to ride in the light colored one any hot day.

    Blaikm had the right idea when he said that clear is black, but I'll go one step further, clear is pure evil and of Satan. It goes back to that surface area thing; it allows for more interior space to be heated faster psi than if your entire exterior were black.

    As for things baking onto your paint, that's another matter entirely. In hot states, I doubt it really matters what color your car is, anything could possibly bake into your paint and it would definitely be more noticeable on a dark car. Dark colors also fade faster under harsh conditions, but then, I don't need to tell you that.

    Having said all that, I have a dark green Solara with a dark interior living in Louisiana. Intelligence? What's that?

    - Slayv1
  • I have a question here: during a hot day, does exterior sheet metal conducts heat more than the sunlight radiating through the windows? Here I assume the window is not tinted.

    In my opinion, the windows should contribute more heat than the metal conduction. The point is how much portion either part contributes. Window 70% and metal 30%? Or simply window 100% and metal none? Can you give your opinion please?

    Thanks,
    Buddhaseed
  • lwflwf Posts: 223
    gobie,

    "The bedouines wear black so they sweat more."

    Most of the bedouin men I saw in my 2 years in Saudi Arabia wore white. The women wear black, but I think that's a cultural/religious thing which has little to do with comfort. And from what I saw of their vehicles, almost all of the bedouin's pickups are without air conditioning and painted white.
  • vivonavivona Posts: 410
    Here's an idea...instead of speculating about whether to buy a dark or light colored car, go to Radio Shack and buy two cheap digital thermometers. Get a type that has a display big enough to see from outside the car. Go to the dealer and tell them you are seriously considering a car, but need some information before you can make up your mind. Find a dark and light colored model of the same car parked reasonably close together and pointed in the same direction to minimize differences. Put a thermometer in each car (in exactly the same place in the car) and close the doors. Make sure you can see the displays. Hang around, look at cars, sit in the shade, etc. until the temperature stabilized in both cars (when the thermometers no longer change) and read which car is the hottest.

    Then post the results here for the rest of us. Tell us the exterior and interior colors of both cars. It would be best if the exterior colors were dark vs. light, but the interior colors were the same.

    As long as you are careful to keep everything but the car color the same, this would be a valid way of getting your answer.
  • previous post great idea, but only if they have donuts & coffee. tell them you want to try it again on a cloudy day to see what the filtered radiation does. I hate dark cars, including mine. Even if it's only the outside that's hotter, I will still notice it if I try to drive with windows down and put arm out. Parked at a stoplight, all that radiating air surrounds you. I think I'm getting paranoid or else they're after me.
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