Hello to all, I'm reading one article about boiler. I have found one interesting fact about air preheater used in industrial boiler. It goes something like this "Approximately 1% of fuel is saved for each 40 F rise in combustion air temperature. Now, since I'm in Europe, I want to know how much this is in deg Celsius. Just want confirmation about this: since Tc = 5*(Tf-32)/9, this will be Tc2 = 5*(Tf1+40-32)/9. This will lead to: Tc2-Tc1 = 40/9 +160/9 = 200/9 = 22.2 C Is this correct?