Dirty Pictures and wishful thinking...

[israndy]

And it would be heavier if it got hot... yeah, think I'll need to see some numbers on your research.

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[S.H.Peterson]

Its quantum physics and it works on a level that will never be real world apparrent.

 

[Kahpernicus]

Its quantum physics and it works on a level that will never be real world apparrent.

Just like CT scalpers.

 

[Crissa]

oh you picky pick person! You know we dissect things to a quantum level around here! We have photometric proof, even!

Yeah, but do photons have weight or mass? Their velocity is enough for one but maybe not the other... depending upon your mathematical model.

-Crissa

 

[CyberGus]

oh you picky pick person! You know we dissect things to a quantum level around here! We have photometric proof, even!

According to quantum mechanics, there is a non-zero probablity that a Cybertruck will spontaneously materialize in my driveway.

I check about once an hour.

 

[cvalue13]

And it would be heavier if it got hot... yeah, think I'll need to see some numbers on your research.

I mean, states have considered banning the sale of black ICE cars for reason of the underlying data on effects to efficiency. There will be similar effects in BEV vehicles on “emissions” equivalent data (eg energy required to condition the batteries/cabin).


Do black cars get hotter in the summer? - “A 2011 study by the Berkeley Lab Environmental Energy Technologies Division discovered that white, silver, and other light paintcolors do improve a car's efficiency. The study, which pitted a silver Honda Civic against a black one, found that light colored cars reflect about 60 percent of sunlight compared to dark colored cars. This translates to a 2 percent decrease in fuel economy (due to increased air conditioner use), a 1.9 percent increase in carbon dioxide emissions, and a 1 percent increase in other harmful emissions for a black car.

The research was published in Applied Energy.
The researchers had two cars in the sun for an hour, one black and the other silver, parked facing south, in Sacramento, California. The silver Honda Civic (shell SR 0.57) had a cabin air temperature of about 5-6°C (9-11°F) lower than an identical black car (shell SR 0.05).”


Thermal Video Showing How Hot Black Cars Get Will Surprise You - “[identical] black and white Highlanders were parked side-by-side, and the [thermal] camera registered a full 46-degree difference between them. Specifically, the hood of the Black Toyota was upwards of 159 degrees Fahrenheit, while the white Highlander only showed 113 degrees.”

Car Color Test: Are Black Cars Really Hotter in the Sun? - “the numbers don’t lie: the cabin of the black car came in at a sweltering 130 degrees, while the white car’s interior was a still hot (not skin-searing) 113 degrees…. Will a white car cool faster than a black one? We took our trusty thermometer and found that the interior of the white car dropped to 84 degrees after 10 minutes, while the black car cooled off a little, but still comes in at stifling 91 degrees.”

 

[israndy]

Any data on Teslas? Isn't that what we are talking about? With their identical glass roofs and identical interior.

 

[Crissa]

Any data on Teslas? Isn't that what we are talking about? With their identical glass roofs and identical interior.

Good question! It's difficult to get identical Teslas, tho.

-Crissa

 

[Cyberman]

This stuff works great on my stainless outdoor grill.

https://weiman.com/stainless-steel-cleaner-spray

Wonder if its available by the gallon

Hmm. Sthmells like oven cleaner.

 

[JBee]

still, the color of the rest of the vehicle matters. Heat comes from all sides (including under), and radiates in all directions.

In 90° weather in a parking lot, an all black Tesla’s cabin temperature will be as much as 10-15° hotter than an all white Tesla, and take as much as 2-3 times longer for the AC to cool off.

Conversely, in a 30° weather parking lot, an all white Tesla’s cabin temperature will be 5-10° coolder than an all black Tesla, and take 2-3 times longer for the heater to warm up.

If a person cares, then buy white in Texas, black in Wisconsin.



-> (nerd with transition lenses)

That's only true if the black car is exposed to radiant heat from sunlight though. If it's in the shade or parked outside overnight the black vehicle will be colder in the morning, or at least reach equilibrium with the outside air during the night faster than a white car.

The surface colour is also particularly important for the transfer of heat into the thermal mass of the vehicle. That means in the summer a black surface will absorb more heat and therefore heat up whatever materials make up the car faster. This is due to the fact that a larger temperature difference leads to incresased heat flow. This stored heat energy requires even more energy to remove with a car HVAC, because now you also have to cool the parts of the car that won't even get warm in the first place in a white one.

Oh, you were talking HONDAs on this Tesla site, you got me confused, I thought you were talking about Tesla vehicles that have glass roofs and no paint over the cabin at all. Now if you were talking about black leather as opposed to white leather, I get that.

Still don't buy this nonsense about heat being heavy. Put a pan on a scale, weigh it, then heat it on the stove, now weigh it again, gosh, it's the same. Shocker

As for glass roof, this depends on if the glass has a IR filter or tint. As pointed out by Peterson, there are three main forms of heat transfer, of which one is radiation. Radiation actually allows a heat transfer to occur through glass as well, so like a greenhouse, heat can get through the glass. Likewise heat can escape from inside to the outside as well. It's possible to freeze water with radiant cooling into space in the desert using a glass covered peice of black metal.

So on a Tesla with glass roof you could have radiative losses from the cabin to the outside, on top of heat loss from convention (airflow) and conduction through the body.

A black interior will therefore not only heat faster in the summer sun, but also cool faster on a winter night. Both of which would be less with a lighter colour like white or stainless, which would consume less energy for climate control, and therefore offer more battery capacity for range instead.

In saying that, if you precondition your car before driving, especially when connected to thebgrid and using its power instead, the effect on range will be less, but it will still use more energy overall than a white one.

As for it consuming more because of the extra weight from the heat, this is likely to be so insignificant it's not worth considering for range....but overall temperature plays a big roll in range in that energy needs to be expended to keep things at operational temperatures (batteries, motors, people etc) but also impacts things like bearing tolerances or how sticky your tyres are on the road.

Even rain significantly reduces range as the tyres are using extra energy to lift water off the road and turn it into water spray.

 

[JBee]

Yeah, but do photons have weight or mass? Their velocity is enough for one but maybe not the other... depending upon your mathematical model.

-Crissa

That's if you believe photons exist or not. If you don't they don't either. So it depends on "your perception", of the model you make of reality....

Many things exist that we have no manifestations of, in our perception, or in physical reality. Likewise, many people just make stuff that anyone would believe.

But the one thing many have wrong is the duality of photons. It doesn't care how we see it, it is, in reality just one.

 

[S.H.Peterson]

Hmm. Sthmells like oven cleaner.

it leaves a slightly oily film that LOVES dust and airborn junk...

 

[CyberGus]

It looks like black EVs are the new "coal rolling".

 

[JBee]

It looks like black EVs are the new "coal rolling".

The only time black is cool on a EV is if it's black, or dark coloured, because it's solar PV cells to charge it.

CT has got to be one of the easiest cars to slap PV cells everywhere on though. I think the dash alone could do 100W.

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