How Heated and Cooled seats work in cars

Have you ever wondered how the ventilated seats in newer cars work? Without really thinking about it, I assumed the seats had hoses connecting to the car's ventilation system.  Where else would they get a stream of cool air?

It turns out, they get it via solid state magic.

Climate controlled seats rely on something called the Peltier effect, named for the man who discovered the process in the early 19th century.  Back the, inventors were experimenting with batteries and electricity, but electric light and all the devices we depend on were still decades in the future.

This is what Peltier discovered: When you pass an electrical current through a sandwich of two dissimilar metals, one side gets cold and the other side gets warm.  It took more than 150 years to turn that observation into an automotive product.

In the photos below you can see the heating and cooling module from Amerigon, a California company that is capitalizing on this effect.  They have a patented device that has made its way into many high end cars, starting with Lincoln.

The fins in the top photo transfer heat or cold into the air, which is pushed by the pancake blower in the photo below, and ducted through the inside of the seat, to flow out gently around the occupant.

Pretty slick, isn't it?

The Peltier effect can raise or lower the temperature by about 10 degrees.  That's not enough to be "ice cold" air on your face, but it's certainly ample for cool air from a hot seat. For perspective, consider the difference between our body temperature and a super-hot shower is just 20 degrees - a lot less than people think.

One day Peltier devices may be used for cooling in electric cars, since they are electrical devices.  A Peltier cooling system would not be as cold as today's refrigeration but would be considerably more space and energy efficient.  I'd look for more from the inventors Amerigon, now known as Gentherm, in the future.

My friend Richard Vaughn was part of the design team that first applied this technology in the 2002 Lincolns. Since then it has spread to all high end cars and is moving toward adoption in all cars. But progress never ceases and new technologies may augment or supersede this soon enough.  The most amazing thing, though, is the fact that this modern innovation is based on an invention that dates to 1834.  And the inventor himself was born in the time of George Washington.  Pretty amazing, isn't it?

Read more in this article from the LA Times

John Elder Robison

John Robison is the founder of J E Robison Service Co of Springfield, MA. His company specializes in the repair and restoration of Jaguar, Land Rover, BMW, Mercedes, Rolls-Royce and Bentley motorcars.  John is also known as an author and advocate for people with autism and neurological differences.  His books include Switched On, Look Me in the Eye, Be Different,and Raising Cubby. John has also written numerous articles on collector car service and repair, and he’s the technical editor for the Rolls-Royce and Bentley Club (the RROC). He’s always available to advise owners about the care and feeding of their fine motorcars.  www.robisonservice.com  413-785-1665