Cool paint job

Reflective paint and glaze can reduce the need for A/C in your car

Posted by Joseph Romm (Guest Contributor) at 4:06 PM on 18 Apr 2008

The following post is by Earl Killian, guest blogger at Climate Progress.

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Cool Car in IR California's AB 32 cap on greenhouse gas emissions has its regulatory agencies working to find a set of measures that will amount to savings enough to cut 2020 emissions by about 30 percent. Since 12 years is too short to change California's vehicle fleet or its power plants, myriad measures are being considered, each rather small but hoped to make a difference cumulatively.

One such effort is to find paints and coatings to reduce how hot cars get when parked, so the driver is less likely to turn on the air conditioner:

This strategy is based on measures to reduce the solar heat gain in a vehicle parked in the sun. A cooler interior would make drivers less likely to activate the air conditioner, which increases carbon dioxide emissions.

Potential approaches include reformulation of paint to reflect near-infrared sunlight, parked car ventilation, and solar reflective window glazing. It is expected that cool paints, together with reflective glazing, will reduce the soak temperature of the typical vehicle parked in the sun by 5 to 10 degrees Celsius.

Some of the work [PDF] appears to be from the National Renewable Energy Laboratory. With the federal government largely AWOL on global warming, it is left to the states to move NREL's research from laboratory to the market. NREL found this:

[T]he United States uses 7 billion gallons of fuel per year for light-duty vehicle A/C, which is equivalent to 5.5 percent of the total national light-duty vehicle fuel use. It takes 9.5 percent of the imported crude oil to produce this much gasoline.

...

A combination of these technologies reduced breath air temperature by 12 degrees C (22 degrees F), seat temperatures by 11 degrees C (20 degrees F), windshield temperature by 20.4 degrees C (37 degrees F), and the instrument panel surface temperature by 16.8 degrees C (30 degrees F).

...

[R]esults show that the A/C load can be reduced by over 30 percent. Vehicle simulations show that the 30 percent reduction in thermal load results in a 26 percent reduction in fuel used for A/C.

Getting into a hot car after it has been parked in the sun is never pleasant, so this falls into the category of a good idea even if it weren't necessary to stop global warming.

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.

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12 Comments | Post a Comment

Maybe

We should also plant more shade trees.

by Matt G at 4:30 PM on 18 Apr 2008

Sunroof

Sunroofs work very well at reducing the need for A/C. The heat rises when parked. When moving the sunroof increases circulation. I have never turned on the A/C in my present vehicle.

by tomrobey at 5:24 PM on 18 Apr 2008

Convertibles

We blast the A/C in enclosed cars.

Yet, a convertible is a status symbol.

Doesn't make sense...

Texeme.Construct(function(x)=Participation(x))

by jabailo at 6:25 PM on 18 Apr 2008

Painting the Titanic

This is a bit like painting the Titanic.

Far better to spend time and effort on creating transportation choices for people so they are not forces to drive everywhere.

by racc at 6:38 PM on 18 Apr 2008

Don't be surprised ...

"[Don't be surprised, though, if the auto industry experts suggested that all car rooftops should be silvered, and that it'd be a great service to the planet to buy more cars!]"

http://feww.wordpress.com/2007/10/15/only-zero-emissions- ...

by LGT at 7:57 PM on 18 Apr 2008

Driven to Extinction

If we want to have any chance of leaving a living planet for the 22nd century, Americans must reduce their emissions by 80-90% in the next fifteen years. Cars just can't fit into the picture here, except as executioner. We must choose between the apparent comfort of driving or life itself. The message of this article is that we will not choose life.

By the way, when one is on a bike it does not feel nearly as hot as it does in a car, at least at 115F (typical hot summer day in Sacramento).

by human power at 8:06 PM on 18 Apr 2008

I don't see compliance.

Similar things can be accomplished by color choice, those portable reflectors, leaving windows cracked, or using the PV powered window blowers. I can't get the other two drivers in my family to do any of that. I don't know what it will take to get more than a few percent of the population to take such nearly painless steps.

by bigTom at 8:42 PM on 18 Apr 2008

They Already Are

Most of the people on the planet don't drive and never will. It is just that not many of the most of people are Americans.

by racc at 11:12 PM on 18 Apr 2008
[ Parent ]

That's ingenuinity, but will it be affordable?

In a developing country where tinted glasses are already considered a luxury for a car, will these special paints have their place in these countries? Developing countries are emitting more CO2 than developed countries, so even though this technology is technically feasible, it will be impractical for residents in impoverished countries to buy a car with such specially coated paintings.

http://environe.blogspot.com

by Sephyrave at 12:10 AM on 19 Apr 2008

Hot weather habits

Here in the Northern Sacramento Valley one circles the block looking for shaded parking from May 1st to November 1st. Front window sunshades are de rigeur and a few fanatics put tyvek covers on thier cars during the day.

I'm seeing increased use of solar panels to cover parking areas but there are millions of acres still available. HINT, HINT. Paradoxically one of the PV shaded parking lots is at the brewery; you can park there but you might not be able to drive home. (it's actually staff parking)

As far as biking in the heat it works far better than biking in the cold. The rider has to be very carefull to allow for a cool down immediately upon stopping because all that heat seems to catch up to you.

Also we freeze out water bottle solid. Two, one-liter bottles are enough for mixed interior/exterior work and four are needed for a full day outside.

I'm starting to see parasols used in the summer. An elegant habit I'd like to encourage.

The bus is always air conditioned.

Put the Carbon Back

by Pangolin at 12:28 AM on 19 Apr 2008
[ Parent ]

Planting shade trees

and planting mushrooms with psilocybin, are both to be recommended.

Those hubcaps are glowing, man. And butterflies are emerging from the one in front; but earthworms, from the one in the rear ...

Chickens deserve our true friendship! So do fish! So do other sentient beings! Let us learn to be kind.

by caniscandida at 12:50 AM on 19 Apr 2008

Per Capita Emissions

Don't get stuck on the "Developing countries are emitting more CO2 than developed countries" line. Of course they are. There are far more people in these countries. What really matters is per capita emissions and people in developed countries are emitting far more ghg gases than people in developing countries.

Impoverished people are not buying cars. It is only a small percentage of people in these countries that will ever be able to have a car. Do something about what is happen in your backyard before worrying about somewhere else. Its called leadership.

by racc at 9:31 AM on 19 Apr 2008

ADVERTISING POLICY

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