CARB Holds Workshop to Discuss "Performance-Based Options"
for Solar Glazing Regulations; Final Draft to be Released by End
September 17, 2009
The California Air Resources Board is holding a workshop today
in El Monte, Calif., to discuss the Performance-Based option for
the recently adopted "Cool Cars" regulations, which call
for enhanced auto glass to reduce the use of air conditioners in
vehicles in the state. CARB calls for total solar energy that enters
a vehicle through the glass to be reduced by 2014 using both solar-absorbing
and infrared-reflective glass.
The regulations call for an even further reduction of solar energy
by 2016-using either solar-absorbing or infrared-reflective glass
or "a combination of technologies that result in equivalent
reduction in solar heat gain." The aim of today's workshop
is to discuss a test by which the "equivalent reduction in
solar heat gain" can be measured.
The group is proposing two tests for the temperature based metric-one
for stationary parked cars, and one for moving vehicles. In addition,
CARB is proposing a possible CO2-based test, which would measure
the vehicle's internal temperature and differences in CO2 emissions
to reach a "comfortable temperature," according to today's
There are still many questions to be answered, though, if the CO2
test were adopted-such as what a comfortable temperature is, what
test cycle would be used, and how the test correlates to actual
driving conditions, according to a presentation from CARB.
The group also notes that a CO2 test could be somewhat complex and
costly, and would need to be in place by the middle of 2016.
The final text of the regulation is scheduled to be released by
the end of October, at which point a 15-day comment period will
begin. The final regulation must be approved by May 2010, according
to information from CARB, so it can be submitted to the full Board
for review in summer 2010.
In the current draft of the regulation, the first tier of the current
regulation draft calls for the following: 50 percent TTS through
the windshield, 60 percent TTS through the sidelites and backlites
and 30 percent TTS through sunroofs. The second tier calls for a
further reduction of TTS-to 40 percent in 2016, for all except the
sunroof, for which CARB calls for 30 percent TTS in 2016, or a combination
of technologies to achieve the equivalent result.
The regulations initially focused on the use of reflective paints,
but during their development, the paints effort was dropped and
glazing requirements were added. The regulations came about as a
result of California AB 32, a bill passed in 2006 aimed at reducing
the state's greenhouse emissions. The goal of the glass regulations
is to reduce the load on a vehicle's air conditioner by cooling
the vehicle through the glass.
The regulations were then extended to include a possible equivalent
for the 2016 phase, during the June hearing during which the board
voted to adopt the regulations, at the suggestion of several in
attendance, including CARB member John Balmes.
"I feel much more comfortable with performance-based standards
were there are alternatives available, because I just think we get
into trouble when we try to be too prescriptive about any one specific
technology," he said.
Another board member noted at that time that by extending the regulations
beyond the glass, it opens it up for something the entire nation
might take on.
"But if our true goal is to reduce greenhouse gases, I think
the most important thing we can do is to write a regulation that
is not just used in California but is used throughout the
United States," said CARB member John Telles. "And if
we have something that is too prescriptive or whatever, that is
not being-that cannot be incporated in the rest of the United States-then
we-then we haven't really accomplished our goal. We've just kind
of put a little bit of water in the bucket, but didn't fill the
HERE for full text of today's presentation.
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