Hypercar Air Conditioning

Flawless air conditioning is one of the most important aspects of any car, but a 400km/h-plus top speed does tend to complicate matters

- Scott Newman

DR JULIA LEMKE HAS a very cool job. Her official title is the overall technical coordinator for the air conditioning systems in the Bugatti Chiron and its associated variants and we promise there will be no more puns in this article. You might think that designing an air conditioning system is a breeze (okay, sorry, that’s the last one, promise) but the task becomes somewhat more complex when the car involved is capable of well over 400km/h.

Lemke was a qualified historical archivist before going on to study energy and process engineering, writing her doctoral dissertation on “Energy assessment of car air conditions systems with secondary circuits”. This knowledge made Lemke the perfect candidate for solving the problem of keeping one of the world’s fastest cars cool.

Most vehicles draw air into the interior from the base of the windscreen, but in a Bugatti this area switches to negative pressure at 250km/h, meaning air would be sucked out rather than drawn in. To overcome this, a ram air flap and “optimised blower” ensures air continues to be forced into the interior.

The Chiron’s top speed potential creates further issues. Its aerodynamic needs demand a steeply raked windscreen – 21.5 degrees rather than around 30 degrees in a conventional car – which substantially increases the surface area from 0.7m-squared to 1.31m-squared. In turn, this heats up the interior more quickly thanks to the greater solar load, a problem only exacerbated by Bugatti’s Sky View glass roof option.