On 23/04/2017 22:09, Tim Streater wrote:

Actually Tin-Tout/Tin. Which equals 1 - Tout/Tin.

OK, I'm not a physicist.

And the reason its degrees K is because the kinetic energy in a gas is
proportional to its temperature in K. Just look up thermal efficiency
in Winky.

But I'm enough of one to know that while one kelvin is equivalent to one
degree celsius, it isn't a degree. It's just a kelvin.

Andy