Do Black Cars get Hotter than White Cars?

backcarwhitecarshot

Until finish converting this article from the other site, the short answer is no. Theres a bunch of tests I did one Saturday but the simple explaination is that black cars get hot faster. You would  notice this if you get in and out of your car many times a day but if a white car and a black car are in the beating sun all day - the cabin temp would be the same. Yes white is cool to the touch but the big heat collectors are the windows. "I have a solar windshield covering thingy" you say. That just keeps the excessive heat from the DIRECT sun off  of your steering wheel but still fills the car with the hot air generated between the glass and the fabric thing.

Oh, and example of direct sun heating vs ambient. Ambient is the temp of the air around you, direct is the heat that the light radtion interacting with the materials surface. An perfect example of this is resting and burning your arm on an iron gate on a sunny day.

 

After I bought my oven probe kitchen thermometer, the first thing I needed to find out was exactly how hot my car got sitting in the sun. The details were:

cgMedium 4Runner interior
cgMedium  Windows rolled up
cgMedium  2:30pm
cgMedium  Tucson, 110 outside

The cooking thermometer was needed for placement flexibility and a wider temperature range than outdoor models.

 
expBlackWhite01
  Not realated, just wanted to measure the A/C efficiency with the car stopped vs in motion

expBlackWhite01

 

  The experiment: This is the first of a series of experiments to prove or disprove what gets hotter in the sun. Does a piece of black steel get hotter than the inside of a glass jar? Will a potato remain cooler at its core than the outside air? Since things like this have kept me awake at night for the past few years – I’ve decided to finally do a quick series of heat experiments. Hopefully the results presented below can be interpreted and twisted to give you an idea of other scenarios – say the difference between the inside of a car vs. the hood based on the glass jar test.

expBlackWhite01

 

  Might be hard to see but basically between every measurement - the thermal probe was hung up in the shade to cool off. expBlackWhite01
  All off these samples were done at the same time, separated only by a minute to let the probe cool down. All the samples were taken within 15min during a cloudless July day.

cgMediumInside the glass jar = 136 degrees F
expBlackWhite01
 
cgMediumInside a black steel box = 134 degrees F
expBlackWhite01
  cgMediumInside a piece of square steel stock, unpainted expBlackWhite01
  cgMediumInside a potato after an hour. Remember it was only 101 outside. expBlackWhite01
  cgMediumThe leather glove - pretty hot... too hot to wear actually. And yes, I'm a wimp. expBlackWhite01
   

cgMediumThe White car vs the Black Car cgMedium

The key photo I neglected to shoot back in 2003 was the dual mesurement of the black painted box and an identical steel box spray painted white. The results were they both got up to 136 BUT the black box hit this peak temperature in one third of the time.

There you have it. I'm sure there are a few erronious elements to my setup but the results at least show there is a lot less difference in car color than one might expect.