How can somewhere so hot be so cool? Well if you’re driving along in California it’s probably because of windows that reflect or absorb heat-producing rays from the sun.
The California Air Resources Board has now adopted regulation that will require new cars sold in California from 2012 onwards to be fitted with these windows. The aim of the scheme is three-fold – to keep cars cooler, to increase fuel efficiency and to reduce greenhouse gas emissions.
Cooler cars will mean less use of air conditioning, which in turn increases fuel consumption and prevents around 700,000 metric tons of carbon dioxide from entering the atmosphere. This is the equivalent of taking around 140,000 cars off the road for a year.
However, the state will not be adopting a plan proposed for a cool cars measure based on reflective paints. The Air Resources Board chose to drop the consideration of a cool paint regulation after determining that the paint technology was not ready. Its concerns included that greenhouse gas emissions from reflective paint were considerably below the levels expected; that black reflective paint was not commercially acceptable; and that the paint would have durability concerns in terms of potentially suffering chips and scratches.
So instead the Air Resources Board chose glass technology as a way of reducing the vehicle cabin temperature and air conditioning use. Broadly, there are two forms of this technology: infrared reflective glass, which requires the window to be laminated; and solar absorbing glass, which is laminated or tempered with a solar absorbing material.
Compared to existing cars already in showrooms, the solar control glass technology should block 33 per cent more heat producing rays from the sun.
