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Old 04-19-2019, 07:29 AM   #23 (permalink)
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Originally Posted by hayden55 View Post
I've always read the exact opposite.

"The researchers developed a thermal model that predicted the air conditioning capacity (rate of heat removal) required to cool each vehicle to a comfortable final temperature of 25C (77F) within 30 minutes. (This is an industry standard for vehicle air conditioner performance.) Based on the experimental measurements, the analysis predicted that the capacity required to cool the cabin air in the silver car is 13% less than that required in the black car."

"Using a white or silver paint (solar reflectance = 0.60) instead of a black paint would raise fuel economy by 0.44 mpg (2.0 percent). It would also decrease carbon dioxide emissions by 1.9%, and reduce other automotive emissions by about 1%."

I know the Prius has a 4500w HVAC so that would equate to about 292.5 watts saved for that 30 minutes then level off. That's pretty significant given its smaller hybrid battery and how much using the hvac kills the battery around town when the engine is off at stop signs or coasting.

I remember reading a more detailed report in 2016 on window tints, and vehicle colors but I couldn't find that one.

I second the IR gun in a parking lot. You could easily measure roof surface temp and cabin temp with them. I'm gonna do that one day when I'm roaming around campus with my IR gun.

I'd say when you get some measurements buy a can of white plastidip and have at it.
That's probably correct.
The article I read the cars where parked with windows up for the test. Although all cars reached the same temp the dark cars got there quicker so logically the ac would need to work harder in dark cars to combat the temp rise.
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